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pereira [Technical Aspects of the S800]
+++ start [2020/11/06 13:17]
pereira [Operation of the S800]
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 ====== The NSCL S800 spectrograph ======
-Welcome to the wiki page of the NSCL S800 spectrograph. The page provides technical information about the S800, as well as instructions to operate the S800 prior to and during an experiment.
+Welcome to the wiki page of the NSCL S800 Spectrograph and S3 vault. The page provides technical information about the S800, instructions to operate the S800 prior to and during an experiment, and some general maintenance information of the S800 and S3 vault. Support of the S800 is provided by Jorge Pereira ([[pereira@nscl.msu.edu]], ext. 77428) and Shumpei Noji ([[noji@frib.msu.edu]], ext. 77600). Details on the Service Level Description of the S800 can be found in [[https://www.nscl.msu.edu/users/s800_sld.pdf]]
+All users of this site are personally responsible for full compliance with the export control regulations of the United States and/or any other jurisdiction of which they may be resident.
+For questions related to this Wiki document, please contact  Jorge Pereira.
 ===== Technical Aspects of the S800 =====
@@ Line 10: / Line 12: @@
   * [[Modes of Operation]]
   * [[Determination of Angles and Momentum]]
+  * [[Determination of Angles and Momentum#Calculation of the inverse map|Calculation of inverse map]]
   * [[Detectors]]
   * [[Electronics]]
   * [[Data Acquisition (DAQ)]]
-  * [[S800 Software]]
+  * [[S800 SpecTcl|S800 analysis software (SpecTcl)]]
-  * Coupled Detectors/Devices
+  * Coupled Devices
-  * Types of Experiments
+  * [[Types of Experiments]]
 ===== Operation of the S800 =====
+  * [[Preparation for tuning the S800]]
+  * [[Tuning the S800 (XDT)]]
+  * [[During experiments]]
+  * [[Division of operation responsibilities]]
+  * [[Venting/pumping vacuum sections in S800|Venting/pumping vacuum sections in S800]]
+  * [[Radiation safety in the S3 vault|Accessing and securing the S3 vault]]
+  * [[General documentation S3 vault|Documentation S3 vault]]
+  * [[Troubleshooting]]
+  * [[Shutdown S800/S3 Vault]]
-==== Magnets ====
-=== Spectrograph Dipoles ===
-Each S800 dipole [3] weights 70 Tons and has a 15 cm gap. The bending radii and angle are 2.8 m and 75°, respectively. The magnet has five main pieces: two top slabs, the inner and outer side yokes, and the pole tip assembly. The maximum current supplied to the coil is 450 A, translating into a 1.6 T maximum central magnetic field, and a maximum magnetic rigidity of about 4 Tm.  Trim coils are installed on the inner and outer radii of the dipoles to achieve a uniform field near the edges of the magnet. The operating current of the trim coils is 43.75% the value of the magnets. A liquid helium feed circuit brings liquid helium through a heat exchanger at the top of the magnet  and delivers the liquid into the bottom of the coils. The helium overflowing the coils fills the dewar to provide cooling for the incoming liquid. Liquid nitrogen is supplied at the bottom of each side. A 0.25 dissipative resistor with a short decay constant is connected to a coil protection switch. In case of cryogenic failure, the switch reroutes the power supplied to the circuit into the resistor. The dipole steel has a 30° edge angle, so that particles are defocused and focused in the dispersive and non-dispersive directions, respectively. The inner and outer radii of the dipoles include trim coils to guarantee the uniformity of the field near the edge.  NMR probes are installed in the flat field region to measure the absolute field setting during operation.
-=== Spectrograph Quadrupole Doublet ===
-In order to maximize the acceptance of the spectrograph, a doublet of superconducting quadrupoles is installed upstream of the two main dipoles [3]. The doublet focuses  the transmitted particles first in the non-dispersive and then in the dispersive directions. The quadrupoles are the iron-dominated type used in the NSCL beamlines, but with larger dimensions.  The pole tip of each quad has a length of 30 cm, and a radius of 12 cm for the first quad and  21 cm for the second one, i.e. almost twice and three times larger than the beamline quadrupoles, respectively.  The doublet weights 5 Tons, including the sextupole at the end of the second quad. The field gradient  of the first quadrupole is 19.7 T/m at a maximum operation current of 86 A. The field gradient of the second one is  7.5 T/m at a maximum operation current of 90 A.  Both quadrupoles have cryogenic Hall generators mounted on the pole tips to measure the  field gradient during operation.  The quadrupoles don’t have protection circuit since they can quench with no damage to the coils.
-=== Spectrograph Sextupole ===
-The only high-order magnet included in the S800 is a sextupole coil  installed around the bore tube of Q2. The purpose of this element is to correct the broadening of the beam at the focal plane due to the dominant (x|2) aberration. This defines a narrower trajectory of the beam, allowing the use of a beam blocker at the focal plane to block the unreacted beam when its magnetic rigidity is close to the tuned setting.
-====== Headline ======
-====== Headline ======
-====== Headline ======
-====== Level 1 Headline ======
-===== Level 2 Headline =====
-==== Level 3 Headline ====
-=== Level 4 Headline ===
-== Level 5 Headline ==
-----
-∑
-  * Unordered List Item
-  *   * Unordered List Item
-  *   * Unordered List Item
-  *   *   * Unordered List Item
-* Technical Introduction
-  * Ion optics
-  * Detectors
-      * SCI OBJ
-      * TPPACs
-      * CRDCs
-      * IC
-      * FPSCI
-      * Hodoscope
-  * Electronics
-      * Diagrams
-      * Triggers
-      * Signal optimization
-  * Software
-      * Log in to use different applications
-      * Barney
-      * Bklq
-      * Panel Mates
-  * DAQ
-  * Experiment types
-      * Coulex
-      * CE
-      * Knockout
-      * ...
-  * Supported detectors (Background suppression):
-      * Gamma
-      * CAESAR
-      * SeGA
-      * GRETINA
-      * Neutron
-      * LENDA
-      * Charge particle
-      * HiRA
-  * Organization of responsibilities: device physicist vs. experimenter (training)
-  * Planning an experiment with the S800
-**THE S800 SPECTROGRAPH**
-INTRODUCTION
-The S800 [xx] is a superconducting spectrograph used for reaction studies with high-energy radioactive beams produced at the NSCL Coupled-Cyclotron Facility (CCF) and the A1900 Separator [xx]. It was designed for high-precision measurements of scattering angles (ΔΘ=2) and momentum (p/Δp=2×104), and large momentum and solid-angle acceptances (ΔΩ=20 msr, Δp=6%). The S800 layout is shown in Fig. 1. It consists of two parts: the analysis line and the spectrograph. The analysis line extends from the object position to the target station. It includes four 22.5° dipoles, five quadrupole triplets, and two vertically steering magnets, assembled in two segments with configurations QQQ-H-DD-QQQ (segment 6) and QQQ-DD-H-QQQ-QQQ (segment 7) symmetrically oriented around an intermediate image plane. The spectrograph consist of two quadrupoles, a small sextupole and two big 75° assembled in a QQ-S-DD configuration (segment 8) that spans vertically from the target station to the focal plane. Table xxx summarizes the features of the different superconducting magnets.
-The analysis line can be used in two different modes. In the focus mode, the maximum momentum acceptance is achieved (±2%) by making the analysis line achromatic (with maximum dispersion at the intermediate image plane).In this mode the position of the fragment at the spectrograph focal plane is sensitive to the momentum of the beam impinging on the target. Consequently  the momentum of each particle beam must be tracked, significantly limiting the resolution at the focal plane (to about 1 part in 1000 in energy). In the dispersion-matching mode the whole system (analysis line + spectrograph) is achromatic in the focal plane. The analysis line is therefore highly dispersive (about 11 cm/%) at the target position, limiting the momentum acceptance to ±0.5%. This mode provides the highest possible energy resolution (1 part in 5000 for a 1-mm wide beam spot), since it does not require momentum tracking. The figures of merit of the S800 are summarized in Table 2. Details on the ion-optics can be found in section 1.2.
-In the S800, the angles, positions and energy of the fragments in the reaction target are determined from the angles and positions measured at the focal plane.  The transformation of focal-plane coordinates into target coordinates is done using an inverse transfer matrix calculated by the COSY code [xx] from the measured field maps of the magnets [xx]. In order to correct the high-order aberrations of the system, the transfer matrix is calculated up to fifth order. This order is sufficient to achieve a precision comparable to the resolution of the detectors. (This method is extensively described in appendix A.) The identification of the fragments produced in the reaction target is done by combining the measurements of their time-of-flight and the energy loss in an ionization chamber. In addition, the incoming beam can be tracked before the reaction target using two xxx located in the intermediate image plane of the analysis line.
-ION OPTICS
-The optical coordinates used in the S800 are described in relation to a central trajectory passing through the center of the S800 magnets, and with the reference momentum given by p_0=qBρ_0  , where ρ_0 is the central bend radius for the dipole, B is the dipole field and q is the ionic charge. The coordinates used in ion-opticcs are the longitudinal distance z along the reference path; and the transversal (perpendicular to z) distances x and y with respect to the  reference trajectory in the dispersive and non-dispersive directions, respectively. The angles  and  are referred with respect to the z axis in the xz-plane and yz-plane, respectively. The momentum coordinate is defined according to the equation + 1 = p / p0 where p is the momentum of the particle. The coordinate l is the distance traveled along the central trajectory in relation to the reference particle, l+1=z/z0…… In ion-optics, the state of a charged particle exposed to the action of an electromagnetic field is characterized by a vector (x y θ ∅ l δ). The coordinates of a charged particle change due to the action of an electromagnetic field. This change can be expressed in terms of a transfer matrix, according to:
-DETECTORS
-The standard detection system of the S800 includes a plastic scintillator at the object station; two tracking detector at the detector station in the Intermediate Image plane; a pair of cathode readout drift chambers (CRDC) located about 1 m apart; a multi-segmented ion chamber, and four large plastic scintillators of thicknesses 3 mm, 5 cm, 10 cm and 20 cm, respectively.
- A timing detection system is included in the object station
-Cathode Readout Drift Chambers (CRDC)
-Two Cathode Readout Drift Chamber (CRDC) are used  to measure the transversal positions and angles in  the focal plane. The first detector (CRDC1) is located at the nominal optical focal plane, and it is separated 1 m from the second downstream detector (CRDC2).  Each detector has an active depth of 1.5 cm, an active area of 26 cm (non-dispersive direction)  × 56 cm (dispersive direction), and it is filled with a gas mixture consisting of 80% CF4 and 20% C4H10 at a typical pressure of 50 torr. A schematic view of a CRDC can be seen in Fig xxx, and their technical specifications are listed in Table xxx. Each detector consists of two windows mounted on frames, two printed circuit boards (PCB) and an anode frame.  Each PCB is made of un-masked G-10, and includes a field shaping foil to ensure a uniform field in the active region of the detector. Two G-10 spacers are laminated to the board on each side. The shaping foils are made of 1.9-mm pitch evaporated aluminum strips perpendicularly oriented to the electric field. The anode frame includes a glued cathode grounding plane, an anode wire running across the field, and a Frisch grid. Cathode pads are located in front of and behind the anode wire. The pads have a pitch of 2.54 mm. The anode frame is sandwiched between the two printed circuit boards with two spacers in between, as shown in Fig. xxx.
-Fig xxx illustrates the principle of operation of a CRDC. The nuclei passing through the detector ionize the gas, dissociating electrons which drift towards an anode wire under the action of a vertical electric field. The collection of charge in the anode induces a positive charge on the cathode pads, which are read out individually. The x position is determined by fitting the charge distribution on the cathode pads with a Gaussian function. The drift time of the electrons to the anode wire, measured with respect to a trigger signal (typically from a scintillator), provides the y position. The resulting position resolution is 0.5 cm. Depending on the position of the track, the typical drift times of the electrons to the anode wires are 0 to 20 s. The relatively long drift times limit the maximum rate that the detector can process properly to around 5000 counts per second . High rates affect also the aging of the anode wire. These problems can be partly  amended by spreading the beam over a large portion of the active area, as it is done in focus mode.
-Both  CRDCs are equipped with digital electronics, which consist of of seven front-end electronic boards designed and developed by the STAR collaboration (RHIC), followed by interface boards connected to a programmable FPGA VME module (XLM72).  Each FEE includes 32 channels of preamplifier shaper, followed by a switched capacitor array (SCA), which acts as an analogic memory, and an ADC.  The processing of signals is driven by the FPGA module. Each SCA samples the signals after a valid trigger is received, and sends  the information into and ADC. The digitized  data are then stored into the internal memory of the FPGA and read out in block mode. The sampling frequency and number of samples read out are adjustable; typical values are 20 MHz and 8 to 12 samples. The time needed for each sampling is around 16 us. Thus, the dead time of the electronics is directly proportional to the number of samples read out. The main advantage of the on-detector digitalization technique used with the CRDCs is the reduction of noise by avoiding the transmission of analog signals (448 from the two CRDCs) outside the vacuum chamber, and the possibility to record multi-hit events like in traditional TPC detectors.
-Active Area	53 cm × 30 cm
-Active depth	1.5 cm
-Number of cathode pads per detector	232
-Number of cathode pads per PCB	116
-Cathode pad pitch	2.54 cm
-Filling gas	80% CF4 and 20% C4H10
-Operating pressure	140 Torr
-Ionization Chamber
-An ionization chamber downstream of both CRDCs is used to identify the Z number of the transmitted nuclei from their energy loss. The detector has an active volume of xxx cm x xxx cm x xxx cm and is filled with P10 gas at a typical pressure of 300 torr, although this value can be increased up to 600 torr for light nuclei. A technical layout of the detector is shown in Fig. Table xxx lists some of the technical specifications. The detector consists of 16 stacked-parallel plate ion chambers with narrow anode-cathode gaps, placed along the detector’s central axis. Each anode is sandwiched by two cathodes foils made of aluminum evaporated mylar.
-The principle of operation of the ionization chamber is illustrated in Fig. xxx. The electrons and positive ions liberated by the ionization of the gas along the particle trajectory drift  towards the closest  anode-cathode pair. The drifting electrons and ions absorb the energy stored in the detector capacity and produce a voltage change of the anodes across the resistor. The main advantages of the anode-cathode configuration is that the electrons and ions are collected on a very short distance (about 1.5 cm), thus reducing pile-up and position dependence of the signals. Moreover, dividing the detector into 16 sections reduces the detector capacitance and consequently its noise.
-Each anode is attached to a small preamplifier inside the ion chamber. This significantly reduces the electronic noise, although it involves the venting of the whole chamber whenever a malfunctioning preamplifier needs to be replaced. The electronic signals from the preamplifier are sent into a 16-channel CAEN N568B shaper/amplifier with remotely adjustable gains. The output signals feed a Phillips 7164H ADC.
-Tracking Parallel Plate Avalanche Counters
-Some experiments are particularly sensitive to the incoming positions and angles of the nuclei impinging on the target. Two tracking parallel plate avalanche counters (TPPAC) are installed in the intermediate image plane of the analysis line. The position and angles measured with both TPPACs are transformed into the corresponding coordinates in front of the target, using the transfer matrix of the second half of the analysis line. The analysis-line dipole magnets downstream of the intermediate image plane filter the particles produced  in the tracking detectors, which would otherwise contaminate the data.
-Each TPPAC has an active area of 10 cm × 10 cm and is filled with isobutane at a typical pressure of 5 torr. The detector consists of a cathode foil with a series of aluminum strips oriented in the non-dispersive direction, followed by an anode plate and a second cathode foil with the strips oriented in the dispersive direction (see Fig xxx). A total of 128 pads are connected to the strips of each cathode foil, with a pitch of 1.27 mm.
-The particles transmitted through the TTPAC ionize the gas, producing electrons and positive ions. The drift of electrons towards the central anode plane induces an image charge on the aluminum strips. The signals are send
-plane
-As mentioned in Section 1, some experiments
-require tracking of the incoming particles before
-they interact with the reaction target. Experiments
-using radioactive beams where an array of detectors
-surround the reaction target are especially
-sensitive to the incoming positions and angles of
-the particles. On the other hand, tracking detectors
-located in front of the target can significantly
-contaminate the data of the experiment. The
-workaround used in the S800 takes advantage of
-the analysis line in which detectors can be installed
-between its two bends, so that most particles reacting
-in the tracking detectors are rejected by the
-last bend. The coordinates of each individual
-particle at the reaction target location are then
-calculated using the transfer map of the second
-half of the analysis line. This method has already
-been applied in some experiments [4] but with
-some limitations, namely the maximum rate that
-can be applied to the tracking detectors.
-Since the
-signals in these detectors occur earlier than the
-valid triggers, they need to be later correlated with
-the correct events. In the past, fast clear or delay
-lines techniques have been used but they are either
-rate limited or degrade the signal too much. The
-SCA contained in the front-end electronics of the
-CRDCs turns out to be the perfect analog storing
-device needed for this kind of application. In this
-tracking detector mode of operation, the SCA
-continuously samples the signals, acting like an
-analog buffer, until a valid trigger is issued. At this
-point, the sampling stops and the SCA pointer is
-backed by a pre-determined number of samples
-(depending on the delay between the tracking
-signal and the valid trigger) to the time when the
-signal corresponding to the trigger occurred. This
-technique allows one to use the tracking detectors
-at their maximum rate capability without affecting
-the quality of the data. It is already being used on
-the A1900 fragment separator parallel plate avalanche
-counters (PPACs) with individual strip
-readout, and will be on the S800 analysis line as
-well as other beam lines at the NSCL.
-The traversing particle ionizes the gas, generating electrons and positive ions.  The charge collected by the anode plate induces an image charge on the aluminum strips connected to the pads.
-b) Particle identification
-• Downstream of the two CRDC detectors are the ion chamber for energy loss measurement,
-followed by a thin plastic scintillator of either 1 mm or 5 mm thickness (default is 1 mm),
-itself followed by a 32-fold segmented CsI(Na) hodoscope.
-• They provide time as well as energy loss and/or total energy measurements.
-• Note that the CRDC detectors cannot function without at least one scintillator to provide a
-time reference to measure the drift time of the electrons.
-• In standard configuration, the ion chamber is filled with P10 gas at a maximum pressure of
-torr and is able to separate elements up to Z=50, after momentum and position
-corrections are applied.
-• The ion chamber now consists of 16 pairs of alternating anode and cathode aluminum
-evaporated mylar foils, . With this geometry electrons and ions are collected on a much
-shorter distance than in the previous empty gas volume configuration (about 1.5 cm
-compared to 30 cm). Both pile-up and position dependence effects are reduced by using this
-configuration.
-• The timing resolution for a point-like beam spot in the focal plane is around 100 ps.
-S800 Spectrograph
-Service Level Description
-August 2012 Page 6 of 14
-bazin@nscl.msu.edu
-• However, this resolution worsens significantly (up to 1 ns) when the whole focal plane is
-illuminated, because of path length differences in such large scintillators. It can be recovered
-by tracking the position of each event on the scintillator from the position and angle
-information provided by the CRDC detectors.
-• The 32 CsI(Na) hodoscope crystals are 2” thick and cover the whole active area of the focal
-plane. They provides a measurement of the total kinetic energy of the particles that stop
-within the crystals. The purpose of the hodoscope is to provide charge state identification
-orthogonal to the traditional A/Q identification provided by time-of-flight measurement.
-Commissioning tests have shown good separation for isotopes up to Z=30 so far.
-. Tracking in analysis line
-The S800 analysis line is equipped with a number of tracking detectors for measuring the
-characteristics of the particles prior to their interaction with the target.
-a) Object
-• The object box of the S800 analysis line contains a thin plastic scintillator (125 μm) for timeof-
-flight measurements. For lighter projectiles, a thickness of 1 mm is also available.
-• This detector is usually left in the beam during experiments and can withstand rates of up to
-MHz.
-b) Intermediate image
-• The intermediate image box is equipped with two tracking Parallel Plate Avalanche Counters
-(PPAC) with individual strip readout for tracking the trajectories of the incoming particles.
-• The individual strip digital readout allows them to function at rates of up to 0.1-1 MHz
-independently of the trigger rate, and with no latency.
-• They cover a surface area of 10 cm x 10 cm and provide measurements of positions and
-angles in both the dispersive and non-dispersive planes.
-• Please note that the tracking PPAC efficiency drops significantly below Z=10, and becomes
-extremely dependent on the intrinsic disruptive limit of the individual detectors, as well as on
-the count rate.
-• The tracking of particles with Z below 10 is not supported at the moment. Some attempts to
-use small CRDC detectors have been made, but have proven unreliable due to fast aging
-problems.
-• The characteristics of the incoming particles at the target location can be calculated in much
-the same way as for the spectrograph, using an optics calculation that relates the coordinates
-at the target to the coordinates at the intermediate image.
-• The principal advantage of this method is to use the final bend of the analysis line to
-eliminate the contamination due to reactions in the tracking detectors.
-• The transfer map between the target and the intermediate image depends on the optics mode
-used in the S800.
-S800 Spectrograph
-Service Level Description
-August 2012 Page 7 of 14
-bazin@nscl.msu.edu
-• Note also that a pair of “classic” PPACs can easily be installed at the intermediate image, for
-tracking secondary beams of low intensity (up to 50 kHz). These have the advantage of a
-simpler and faster readout, but are equally limited to Z>10.
-c) Target
-• As mentioned before in section III, the scattering chamber is equipped with drives that can
-accommodate any kind of tracking detector (with a small adaptation).
-• Standard PPAC detectors (maximum rate 1 kHz) can be installed at those locations.
-However, one has to keep in mind that reaction products from these detectors contaminate
-those produced from the target, and require background runs to subtract their contribution
-when running with thin targets.
-• They should therefore not be left in the beam during data accumulation, and only serve for
-checking the tracking deduced from the intermediate image.
-• Detector systems beyond the standard configuration outlined in this document and their
-readout are entirely within the responsibility of the experimenters. None of the detectors
-installed the scattering chamber are part of the standard configuration.
-F. Electronics
-. Digital
-focal plane CRDCs and intermediate image tracking PPACs are equipped with digital
-electronics.
-• They consist of a number of front-end electronics boards as designed for the STAR TPC
-detector at RHIC, followed by interface boards feeding and receiving data to and from a
-programmable FPGA VME module called XLM72 built by JTEC instruments.
-• Each chain of these 3 components forms an independent data acquisition system of its own,
-driven by state machines programmed into the FGPA.
-• The signals occurring on the detectors are sampled by the electronics and locally stored into
-the internal memory of the XLM72 modules.
-• The sampling frequencies are adjustable, and have typical values of 50ns for the CRDCs and
-ns for the PPACs.
-• The number of samples read out is also adjustable, with typical values between 8 to 12.
-• The dead time of the digital electronics readout and the amount of data to transfer through the
-VME crate are directly proportional to the number of samples.
-• This dead time is around 16μs per sample, therefore the readout code reading sequence starts
-with other modules first (such as Camac), and finishes with the XLM72 modules.
-• The amount of data also depends on how many channels have fired. As there is no data
-reduction performed in the FPGA so far, the relatively large amount of data is read from the
-XLM72 in block mode.
-• A more detailed description of the digital electronics system will be available at
-groups.nscl.msu.edu/s800/Technical/Electronics/Electronics_frameset.htm
-. Trigger
-The first-order optics of the spectrograph is point-to-point in the vertical dispersive direction x,  i.e. (x|θ)=0, and parallel-to-point in the horizontal non-dispersive direction y, i.e. (y|ϕ)=0 (being θ and ϕ the scattering angles in the dispersive and non-dispersive directions). Since the dispersive terms (y|ϕ) and (x|δ) dominate the transport equations, the x and y positions of a nucleus at the focal plane determine the scattering angle and momentum δ (where δ is defined by equation δ+1=p/p0,  being p and p0 the momentums of the transmitted nucleus and a nucleus following the central trajectory, respectively).
-ANCILLARY DETECTORS
-Besides precise momentum and angular measurements, the S800 can be operated in
-	S800 operation:
-	Division of operation responsibilities
-	Preparation for tuning:
-	Software
-	Electronics
-	Gas handling system
-	HV bias
-	NMRs
-	Turn on magnets/settings
-	Pilot (XDT)
-	Unreacted beam
-	Reacted beam
-	Device tuning process
-	S800 scaling (after viewer replaced by target)
-	Detector diagnostics
-	Timing
-	Setting optimization
-	Focus mode (transmission)
-	Dispersion-matching mode (resolution)
-	During experiment
-	Scaling
-	PID
-	Mask calibration
-	Use of blocking slits
-	Handling detectors:
-	Shimming OBJ
-	Replacing OBJ
-	Appendixes
-	DAQ buffer structure
-	Trajectory reconstruction from map fields
-	Documenting
-	Analysis software
-S800 OPERATION
-DIVISION OF OPERATIONAL RESPONSIBILITIES
-Device Physicist
-	Determining biases
-	Operation of gas handling systems
-	Alarm support if initial response by experimenter does not resolve the issue
-User
-	Trigger changes
-	Ion chamber calibration
-	Alarm monitoring and initial response
-	Pivot area vacuum system operation
-User should know how, but Device Physicist needs to be ready to do the job in case user is not ready
-	Rigidity determination for spectrograph settings
-	Implementing TOF and energy loss based PID corrections
-PREPARATION FOR TUNING
-SOFTWARE (Overview and initialization)
-(under development)
-Many things keep changing in the S3 vault and the Data-U6 area as experiment campaigns on the S800 come and go.  This guideline covers the things that should not change.
-The following section concerns the use of computers ……..
-Computers used
-	spdaq20 (S3 vault)
-	Use:  main acquisition computer by both s800 and experimenter account; only one user can run the acquisition at a time
-	Location:  on computer table at S800 FP (top level)
-	Operating system:  linux
-	S800 account:  ???
-	S800FP-PC (S3 vault)
-	Use:  control of FP scintillator bias and control of FP remote gas handling systems (CRDCs and Ion chamber)
-	Location:  top level in east FP electronics rack
-	Operating system:  Windows
-	S800 account:  ???
-	ctl-s3 (S3 vault)
-	Use:  control and diagnostics of hardware systems
-	Location:  on middle level in power supply racks under stairs to top level
-	Operating system:  Window
-	Account:  e.g., “vaultuser
-	devop1 (data U6)
-	Use: device operation
-	Location:  typically located to the left of the electronics racks.
-	Operating system: Macintosh
-	The other computers (a windows PC,
-	 u6pc1 (data U6)
-	Use: Experimenter use
-	Location:
-	Operation system: Windows
-	S800 account: ???
-	u6pc2, u6pc3 (data U6)
-	Use: Experimenter use
-	Location:
-	Operation system: Linux
-	S800 account: ???
-Use of devop1
-The idea behind the use of Macintosh computers for device operations is ensure a stable operating environment.  Daniel Bazin maintains these computers.  Data to support the operation of these computers is stored on a central file system with a RAID-type disc setup for redundancy.  Any of the devop computers can be used for any device and they can be used as backups for each other if one of them fails. Here are some details regarding the computer devop1
-	S800 account:  S800 operations or s800op
-	Six double-screen desktops; navigation among desktops achieved by clicking on desktop background with middle mouse button
-	Drop-down menus appear on the menu bar at the top of the desktop for the application in whichever window is activated
-	To lock the computer, on the desktop menu bar click the user menu (person icon on right) and select Login Window…
-	Knob controls are connected to this computer
-	Important applications:
-	Windows emulator Parallels Desktop
-	Start by clicking on the S800 PC icon under the Operations option on the devop1 taskbar
-	End by clicking the close button on the upper left corner of the window for Parallels Desktop
-	Remote access to the S3 vault computer S800FP-PC by running the program Radmin Viewer via the windows emulator
-	Program is started by clicking “Radmin Viewer” from the emulator’s Start menu; double-click the S800-PC icon and log into the computer using the account s800
-	Click on a button on the toolbar of the window containing the S800FP-PC session to “send Ctrl-Alt-Del” to the remote computer, if needed
-	Remote session on S800FP-PC is ended by clicking on the button on the toolbar of the window containing the S800FP-PC session to “Disconnect and close the window”
-	NCS applications
-	Linux ported applications are available by clicking the Applications icon on the taskbar and selecting the ncsapps option
-	Barney
-	QtKM (Linux application replaces windows application “Control App” for using knobs)
-	Programs not ported to linux (e.g., PanelMate) can be run through the citrix application server on the web (start the browser by clicking on the Safari icon on the devop1 taskbar)
-	Users access the following applications on this computer
-	Trigger GUI
-	Alarm server
-	S800 Detector HV Control
-	Scintillator bias control
-	Focal plane gas handling system control (alarm response and monitoring only)
-	NMR control
-	The F3 button momentarily separates windows on a cluttered desktop
-	The guts for the computer are contained in the package housing the main display
-ELECTRONICS, PATCH PANELS, AND HARDWARE
-data-U6 (south end)
-	Electronic location: two racks that contain all the electronics and patch panels.
-	Oscilloscope TEKSCOPE11
-	Use:  S800 detector/timing diagnostics
-	Location:  left rack on shelf below I3 beamstop control
-	NMR Oscilloscopes
-	Use: NMR resonances display
-	Location: upper two shelves on right electronics rack
-	NIM bin
-	Location: below NMR scopes in right electronics racks
-	Use: Canberra HV supply for Object scintillator
-	Upper patch panels (top of left rack)
-	Cables 1-10:  to object  (not connected in vault; maybe these go to an old target location in the transfer hall)
-	Cables 11-20:  to object
-	Cables 21-25:  to intermediate image box
-	Cable 26 is missing
-	Cable 27-50 should go to pivot point (mostly not connect in vault)
-	Middle patch panel (top of left rack)
-	Cables 51-70:  to S800 FP
-	SHV cables 1-2:  to object
-	SHV cables 6-10:  should go to intermediate image box (apparently not connected in vault)
-	SHV cables 11-20:  to pivot point (not connected in vault)
-S800 FP (top level of S3 vault)
-	Electronics location:  two racks “East” and “West” facing each other on top level of S3 vault on south side of FP
-	Patch panels:
-	SHV Cables 21-30:  to Data-U6 dangling at location of old S800 FP electronics under FP
-	Cables 51-70:  to Data-U6
-	Cables 91-110:  to pivot point
-Pivot point (bottom level of S3 vault)
-	Electronics location:  one rack on bottom level of S3 vault on south side of final analysis line triplet near stairs to middle level
-	Patch panels
-	Cables 75-110:  to Data-U6
-	Cables 70-80:  to object
-	Cables 81-90:  to intermediate image
-	Cables 91-110:  to S800 FP
-Intermediate Image (accessed via middle level of S3 vault)
-	Electronics location:  one rack above intermediate image box located on west end of top level of S3 vault
-	Patch panels (in electronics rack on top level of S3 vault)
-	Cables 21-25:  to Data-U6
-	Cables 81-90:  to pivot point
-Object position (access via middle level of S3 vault)
-	Electronics location:  under first triplet in analysis line
-	Patch panels (mounted on object box support under object box)
-	Cables 11-20:  to Data-U6
-	Cables 71-80:  to pivot point
-	SHV cables 1-2:  to Data-U6
-DETECTOR GAS HANDLING SYSTEM
-General Information
-Required controls and monitoring
-	LabView gas handling system application
-	PanelMate S800vac.MT2 page 07: Focal Plane Detector
-The gas handling systems for both Focal Plane gas-filled detectors – the Ion Chamber and the CRDCs – are remotely controlled via a single LabView application running on the computer S800FP-PC in the S3 vault.  This computer can be accessed remotely via the devop1 computer in Data-U6.
-Note that since the same roughing pump drives the gas handling systems for both gas-filled detectors, extra precautions must be taken to protect one detector from the pressure of the other detector.  The fact that the same pump drives both systems is not indicated on the graphics for the LabView control application
-LabView Control Program
-To start the gas handling system control application, click on the LabView icon FPGHS_TCPIP_Corrected_V01 on the S800FP-PC desktop.
-	A log file should be specified before operating the gas handling system
-	A window automatically pops up asking for the name of the log file when the program starts
-	Use the number of the current experiment (or “test”) as the name of the log file and save in file
-//intranet/files/departments/operations/s800/TO_BE_SPECIFIED
-	The On indicator next to Is VI running? will flash until a log file is specified and the program initiates communications with the hardware
-	Click the Valves tab at the top of the LabView window to display the overview of the gas handling system (see Figure xxx)
-	The triangles on the valve control buttons (as well as the square valve status indicators near the control buttons) are red to indicate that a valve is closed (e.g., control 25 for the CRDC return above) and green to indicate a valve is open (e.g., control 22 for the CRDC bypass above)
-	The gas handling control application should always remain open during the entire time either detector is filled with gas to ensure the log file is continuously updated
-	Once both detectors are empty, this application can be closed with the “X” button on the upper right corner of the window.
-Figure 1:  Gas Handling System LabView running remotelly in S800FP-PC
-Preparation of Gas bottles
-	In Data-U6
-	Ensure I265GV is closed to isolate focal plane vacuum chamber from the rest of the beamline
-	Confirm that the focal plane chamber is under vacuum
-	Confirm that the only open gas handling system valves are 4, 5, 6, 20, 21, and 22
-	In the S3 vault
-	Ensure that the gas handling system roughing pump is running and has a good vacuum
-	The pump sits on the floor under the focal plane behind the south support post (PICTURE GOES HERE)
-	The display unit for the pressure at the pump has a needle indicator and is mounted under the focal plane on the south support post (PICTURE GOES HERE)
-	Ensure that the main valves on the gas bottles are open
-	Ensure that the gas bottles are not empty
-	The gas regulators are not normally adjusted.  They should all be set to provide a pressure around 20 psi.
-	The bottle supplying the P-10 gas for the ion chamber is secured to the cross-brace of the south support for the focal plane chamber.  It has an electronic Ashcroft pressure gauge upstream of the regulator (toggle on and off with the “on/off” switch) and a mechanical pressure gauge downstream of the regulator. (PICTURE GOES HERE)
-	The bottle supplying CF4 (tetrafluoromethane) gas for the CRDCs is secured to the cross-brace of the south support for the focal plane chamber.  It has an electronic Ashcroft pressure gauge upstream of the regulator (toggle on and off with the “on/off” switch) and a mechanical pressure gauge downstream of the regulator. (PICTURE GOES HERE)
-	The bottle supplying isobutane (C4H10) for the CRDCs is secured to the south support post for the focal plane chamber.  It sits on a scale for monitoring the isobutane consumption – the electronic display for the scale sits on the chiller unit under the focal plane chamber.  It has a mechanical pressure gauge downstream of the regulator. (PICTURE GOES HERE)
-Filling Ion Chamber with Gas
-	Follow instructions under PREPARATION FOR FILLING DETECTORS WITH GAS above
-	Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) while detectors are being filled with gas; the pressure normally stays below 5E-5 Torr.
-	Confirm that the detector pressure as indicated by the display labeled P.T. #1 reads below a couple of Torr
-	To zero this display:
-	Click on the Slot 3 (PT1) tab to access the details page for PT #1
-	Click the Zero Sensor button
-	Click the Valves tab at the top of the LabView window to return to the overview display of the gas handling system
-	Close valve 6
-	Open valve 2; the flow reading at MFC #1 should jump momentarily
-	Fill Ion chamber
-	Enter the desired fill pressure and start the automatic filling process
-	Click on the tab labeled Slot 8 (M-card) IC to access the page with the pressure set point control
-	Enter the desired pressure (typically 300 Torr) in the field under the knob labeled Set Point
-	Click button labeled Return to AUTO Mode on left to start filling/regulation
-	Click the Valves tab at the top of the LabView window to return to the overview display of the gas handling system to monitor filling
-	The flow readings for MFC #1 will increase and eventually disappear as the readout value overflows the display field (this is normal behavior)
-	If necessary, the filling process can be stopped at any time by pressing the valve button labeled Close MFC #1
-	Open valve 9
-	The filling process will take several minutes
-	When the detector is filled, close valve 5
-Filling CRDC1 and CRDC2 with Gas
-	Follow instructions under PREPARATIONS FOR FILLING DETECTORS WITH GAS above
-	Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) while detectors are being filled with gas; the pressure normally stays below 5E-5 Torr.
-	Confirm that the detector pressure as indicated by the display labeled P.T. #2 reads below a couple of Torr
-	To zero this display:
-	Click on the Slot 4 (PT2) tab to access the details page for PT #2
-	Click the Zero Sensor button
-	Click the Valves tab at the top of the LabView window to return to the overview display of the gas handling system
-	Close valve 22
-	Open valves 10 and 15
-	Open valve 12; the flow reading at MFC #2 should jump momentarily
-	Open valve 17; the flow reading at MFC #3 should jump momentarily
-	Fill CRDCs
-	Enter the desired fill pressure and start the automatic filling process
-	Click on the tab labeled Virtual Ch. 0 (CRDC) to access the page with the pressure set point control
-	Enter the desired pressure (typically 40 Torr) in the field under the knob labeled Set Point
-	Click button labeled Return to AUTO Mode on left to start filling/regulation
-	Click the “Valves” tab at the top of the LabView window to return to the overview display of the gas handling system to monitor filling
-	The flow readings for MFC #2 and MFC #3 will increase
-	The LabView application controls the gas mixing ratio based on the flow ratio (scaled with a calibration constant)
-	If necessary, the filling process can be stopped at any time by pressing the valve button labeled Close MFCs #2 & #3
-	Open valve 25
-	The filling process will take several minutes
-	When the detector is filled, close valve 21
-Removing Gas from Focal Plane Detectors
-	Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) while gas is being removed from detectors; the pressure normally stays below 5E-5 Torr
-	Ensure that the system is in the normal state for flowing gas through the detectors
-	Confirm that the focal plane chamber is under vacuum
-	Confirm that the only open gas handling system valves are 2, 4, and 9 for the Ion Chamber and 10, 12, 15, 17, 20, and 25 for the CRDCs
-	Confirm that the detector pressures as indicated by the displays labeled P.T. #1 for the Ion Chamber and P.T. #2 for the CRDCs show the correct fill values (typically 300 Torr and 40 Torr, respectively)
-	Ensure that I265GV is closed to isolate focal plane vacuum chamber from spectrograph
-	Stop the gas flow into both detectors by clicking valve buttons labeled Close MFC #1 and Close MFCs #2 & #3
-	Isolate the gas supply by closing valves 2, 12, 17, 10, and 15
-	Open valves 5 and 21
-	IMPORTANT:  CLOSE VALVE 25 to protect CRDCs from Ion Chamber pressure
-	Empty Ion Chamber to a pressure at or below the pressure of the CRDCs
-	Open valve 8
-	Wait for the Ion Chamber pressure to reach or drop below the pressure in the CRDCs; this process will take several minutes
-	Finish emptying both detectors
-	Open valve 25
-	Open valve 24
-	Wait for the pressure in both detectors as indicated by the displays labeled P.T. #1 and P.T. #2 to reach 0.5 Torr or less; this process will take at least an hour
-	Close valves 9 and 25
-	Close valves 8 and 24
-	Open valves 6 and 22
-	Enter vault and close main valves on gas bottles:  P-10 for Ion Chamber isobutane (C4H10) and CF4 (tetrafluoromethane) for CRDCs
-DETECTOR BIAS CONTROL
-(under development)
-General Information
-The TPPACs, the Ion Chamber, and the CRDCs have ISEG power supplies run through a single VME-based bias control.  The computer interface for this bias control, the S800 Detector HV Control, is typically run on the devop1 computer in Data-U6 and is started by clicking on S800 HV under the Operations option on the taskbar. The Object scintillator and the FP Scintillator are each controlled separately as described below under the sections for each detector.
-Object Scintillator
-The bias for the object scintillator is controlled via the Canberra HV supply located in the left rack in Data-U6 in the NIM bin just underneath the NMR scopes.
-FP Scintillators
-Only the fist two scintillators are typically used since in most cases particles do not reach beyond the second detector. The biases for the anode and the drift electrode are each controlled separately via the S800 Detector HV Control. To protect the scintillator PMT bases from damage from discharge under poor vacuum conditions (for example, during a window break on one of the nearby gas detectors), the 12-Volt supply for the PMT bases is interlocked to switch off if the pressure in the focal plane box rises above some minimum value as read by an ion gauge.  The ion gauge controller (a black box with an LED digital display) is mounted on the south support structure for the focal plane chamber.  The interlock condition is communicated to the PMT bias supply via a multi-pin “D” connector on the back of the controller.  If the ion gauge is off, the interlock condition prevents biasing of the scintillator.  It is possible to manually override the interlock condition for testing by connecting a “cheater” connector in place of the ion gauge controller to the cable for the interlock.
-Ion Chamber
-The biases for the anode and the drift electrode are each controlled separately via the S800 Detector HV Control. Parts of this detector rely on the same 12-Volt power supply used to power the bases of the FP Scintillator PMTs.  If the vacuum-based interlock condition for protecting the FP Scintillator PMTs is triggered, the 12-Volt power supply will not be available for the Ion Chamber.
-CRDCs
-Each of the two detectors, CRDC1 and CRDC2, has a separate bias control for the anode and the drift electrode via the S800 Detector HV Control.
-TPPACs
-The bias of each of the two detectors, PPAC1 and PPAC2 is controlled individually via the S800 Detector HV Control. There are two types of detectors used for the TPPACs:  either the “classic” PPACs or PPACs with individual strip readouts for handling higher rates.  There is not a difference between the two detector types in terms of how the data is used.  They do differ in terms of electronics and acquisition.
-NMRs CONTROL
-(under development)
-Two digital oscilloscopes are dedicated to NMR readout – one for the analysis line NMRs and one for the spectrograph NMRs
-The scopes are located __________________ and are isolated from clean ground because this signals from the NMR probes are on a dirty ground
-TURNING S800 MAGNETS ON/OFF
-(under development)
-The powering of the S800 magnets needs to follow three steps:
-Arming of Dump Switch
-The power supply for each of the spectrograph dipoles has a dump switch that must be armed to send current through the dipoles. The dump switch is in place to protect the conductors inside the cryostat from melting in the event that the magnet becomes non-superconducting while energized with high current.
-When triggered, a dump switch provides a high-current short circuit path to dump the energy from the magnet.  The kinds of error conditions that will trigger the dump switches are the same conditions that trip off power supplies to other superconducting magnets on the beamlines.  Examples include: a lead drop fault error, a quench detection (read and set values not agreeing over a period of time), a cryogenic error condition (e.g., a low helium level or blown rupture disk), and a loss in flow of cooling water for the power supplies.
-While designed to protect the magnet from a more expensive repair if the magnet quenches when energized, it is possible that the dump switch can get damaged if triggered because of the large amount of energy involved.  Therefore, the magnet should be ramped down before any planned trigger conditions occur.
-The Dump Switches of the two S800 dipoles are located in second level of S3 (see picture xxx). In order to arm the switches .xxxxx
-Set S800 magnets currents to values of running setting
-	Open the Panel Mate screen THallps
-	 Turn on S800 magnets by clicking in the box with the corresponding name (e.g. I228DS), followed by a click in the ON box. (Go through pages xxx to cover all magnets.)
-	Go to page xxx and select the steering magnets: ONLY THE S800, xxxxxx. Note that some of the power supplies are connected to more than one steering magnet. If necessary, disable the steering magnet of the other line and enable the correct one.
-	Load setting:
-	Open Barney
-	Select S3, followed by S800 (see picture)
-	For each of the three segments (segments 6, 7 and 8), enter value of magnetic rigidity and click on the button Set setting (see picture)
-PREPARATION FOR TUNING
-In S3 vault
-	Arm dump switches
-	Make sure object ion gauge is off
-Go to page xx on Panel Mate xxx. Check status xxx
- Ensure viewer is ready
-	Make sure gas bottles for FP detectors are open
-	Make sure Intermediate PPACs have gas
-In data-U
-	Start Software tools
-	PanelMates
-	NMR GUIs
-	Barney
-	Labview Gas Handling System Controls
-	Labview Bias Controls
-	Alarm servers and monitors
-	Linux HV controls (alarm server should be started first)
-	SpecTcl (alart server should be started first)
-	Run Control (in coordination with experimenters)
-	Trigger Control GUI (in coordination with experimenters)
-	Scalers (in coordination with experimenters)
-	Put 10 Amps in Spectrograph dipoles
-	Start gas in detectors
-Refer to Section xx (S800 Focal Plane Gas Handling System Operation)
-	Enable crad04 with a rate limit of 20 kHz (crad04 looks at E1 up)
-	If it does not interfere with experimenter preparation (see “Unreacted Beam” section below)
-	Set spectrograph Brho
-	Start scalers
-PILOT BEAM (XDT)
-Unreacted beam
-Send beam to FP
-	Ensure that crad04 is enabled with a rate limit of 20 kHz (crad04 looks at E1 up)
-	FP rate limit:  6 kHz
-	Bias S800 FP scintillators
-	Set bias to best guess based on previous experience for the fragment Z being used
-	Typical values:
-V E1 up/down
-V E2 up/down
-	Have a good expectation of rate from A1900 group information or from timing scintillators
-	remove stops to look for beam at S800 FP with scalers and adjust beam rate with attenuators
-	Look at FP scintillator scalers
-	There are typically a few scaler counts without beam
-	Ion chamber does not have scalers
-Object scintillator setup
-	Use scope to look at signal patched out to data-U6
-	This signal is a copy of what goes to cfd in vault
-	Good signal height:  400-500 mV
-	Typical bias:  1200-1800V (up to 2200 V)
-	Typical current:  _________
-	Watch for no rate change on scaler display with a bias adjustment up or down of ~50-100 V
-FP scintillator setup
-	Set trigger to “s800 trigger”
-	Start trigger GUI by clicking icon in “Operations” area
-	Under trigger tab select “s800 trigger” (which is E1 up by definition)
-	Deselect experiment trigger
-	SAVE TO FILE
-	Stop and start daq to assert new trigger condition
-	start spectcl
-	Adjust bias looking at down vs. up 2D spectra for each scintillator
-	See sketch below
-	Bias changes stretch curve (i.e. shift spot corresponding to typical unreacted beam)
-	Adjust biases so that unreacted beam are at 1/3 to ¼ of dynamic range
-	Reaction product will typically be similar enough to unreacted beam particles
-	Different particles with different e-loss will shift the curve corresponding to particles covering whole FP
-	Biases for K-48 @ ~95 MeV/u
-	E1_UP/DOWN:  1550/1500V
-	E2_UP/DOWN:  1350/1390V
-Ionization Chamber setup
-	Gas should be flowing
-	Bias detector
-	Start alarm server under “operations”
-	Start HV application under “operations”
-	Typical bias
-	Anode:  200V (should not draw current after bais reached)
-	Drift:  800V (typical current:  <80)
-	K-48 at ~95 MeV/u:  Anode/Drift:  800/200V
-	This is not a sparky detectors
-	Adjust pad gains
-	There are 16 pads each providing dE information in the Z (beam) direction
-	The idea is to make sure the dynamic range is OK so that heavy particles do not saturate the spectra; the pad gains do not have to be matched
-	Use summary 2D spectra “IC.raw”
-	Gains are controlled in “s800shpini.tcl” file in the current directory
-	This file can be edited with the bbedit editor by double clicking on the file in the browser
-st shaper is for ion chamber
-	typically only coarse gains are used
-FP CRDC setup
-	Bias CRDCs
-	Look at anode signal on scope while biasing drift and anode
-	Patched to data-U6 on labeled connector
-– 500 mV signals are good
-	Typical starting values:
-	Drift:  500 V (800 V used for K-48)
-	Should draw current with bias applied
-	Anode:  500-600 V (800 V used for K-48)
-	Should not draw current after set value reached
-	Watch signal as setting in 100 V steps
-	Gate: 20-40V (adjust to optimize signal height compared to noise)
-	K-48 @ 95 MeV/u
-	CRDC1 Anode/Drift:  800/800 V
-	CRDC2 Anode/Drift:  800/800 V
-	Gate:  26V
-	Not a sparky detector
-	Should see counts on scalers
-	Count rate a little higher than on scintillator due noise or thresholds
-	Check spectra
-	 “crdc1.raw” and “crdc2.raw”
-pads in dispersive direction
-	Sketch shows typical spectra
-	Width of beam peak is proportional to A1900 p-acceptance in focus optics
-	Width is narrower in match optics
-	Adjust anode to bring fuzzy maximum to around 600-700 channels
-	ADC full range for each pad is 1000
-	Can look at y vs. x 2D spectra as a sanity check
-	Remember that the y-parameter is not reliably calibrated at this point
-	“crdc1.tac” and “crdc2.tac” provide raw y-parameter (confirm these spectra titles _____________________)
-	Mask calibration
-	Unreacted beam does not provide good conditions for performing the mask calibration, but sometimes it provides the only option
-	To cover mask
-	Detune non-dispersive y quad (ratio=0.5) in spectrograph to spread beam in y
-	Sweep beam across dispersive direction using spectrograph dipole
-Timing setup
-	See http://groups.nscl.msu.edu/s800/Technical/Electronics/Electronics_frameset.htm for background information on the trigger setup
-	The TDC delays can only be changed when the run control is stopped; must SAVE settings before starting run control not to overwrite adjustments being made
-	The “S800” trigger is from E1 up signal
-	Trigger the scope with the “Live Trigger” signal patched to data-U6
-	There are 4 trigger inspect channels patched to data-U6 that can be assigned using the trigger GUI
-	Examine the timing of each of the selectable listed signals with respect to the “Live Trigger” signal
-	There are 4 TDC inspect channels patched to data-U6 that can be assigned using the trigger GUI
-	The full range of the TDC is 400 ns
-	Set each timing to 200 ns
-	TDCs of last 4 listed signals (including XF and object scintillators) are bypassed with cable delays inside the vault and thus their delays cannot be controlled with the GUI
-	They can be inspected, however using the GUI
-	Information
-	The signal delays controlled by the GUI (and not by cable delays) are not “pipelined” – i.e., any new signals that arrive during the delay time of a previous signal are lost and thus deadtime is introduced into the system.  The signals delayed passively by cables are “pipelined” and thus are not subject to deadtime losses
-	All of the trigger signals are not pipelined and are thus subject to deadtime
-Checking Particle ID and rate at S800 FP
-	Establish PID
-	Refer to information on setting from A1900 FP
-	dE-TOF
-	dE signal from Ion Chamber
-	TOF from XF or Object scintillator to S800 FP
-	Not necessary to implement dE- or TOF-based corrections
-	Document rate of fragment of interest with run to disk
-	Measure beam current with appropriate Faraday cups
-	Timed run
-Analysis line classic PPAC setup (Focus optics only)
-	“Classic” PPACs are the default detector, not TPPACs or CRDCs
-	Classic PPACs have rate limitations from pileups
-	TPPACs are not as efficient as CRDCs for low Z because it is not currently setup to set thresholds on individual pad readouts
-	Checking PPACs with beam
-	Scalers do not provide reliable diagnostic information because of noise
-	Bias PPACs while looking at patched out anode signal on scope to check for sparking
-	Typical starting value:  400V
-	K-48 @ 95 MeV/u biases:  PPAC1=580V, PPAC2=540V
-	Look at spectra of raw up, down, left, right, anode to decide on bias
-	Run with smaller p-acceptance (e.g., 0.5%)
-	Efficiency against Focal plane CRDCs should be 100%
-	Optimize bias setting based on raw signals
-	Check that position spectra look reasonable
-	Run with larger p-acceptance (e.g., 2%)
-	Efficiency against Focal plane CRDCs should be 100%
-	Record run showing tracking
-	Confirm angular dispersion: ~50 mrad/% (not an absolute measurement)
-	Confirm correlations between dispersive angle at intermediate image and p in FP (e.g., crdc1x)
-	This correlation will be somewhat washed out by straggling in the target; in principle, this should be checked without the target, but the benefit vs. cost in time to remove the target is not worth it.
-Setup beamline
-	Object and XF scintillators and intermediate image PPACs inserted if they will be used
-	If Object scintillator will not be used, there is no reason to look at beam on it unless to debug a problem with the transmission
-	Set spectrograph Brho for unreacted fragment
-Start scalers
-	Use s800 account
-	Make sure experiment daq is:
-	Stopped
-	Gone
-	Open terminal window (from bottom of mac)
-	ssh to spdaq20
-	ps auw | grep Readout
-	Does not get restarted
-	Under operations folder on mac
-	scalers (gives error if no bridge)
-Setting Optimization
-	Focused optics
-	Expectations for A1900 FP to S800 FP transmission
-% or better for mid-Z fragments
-	>60% for low-Z fragments with large angles
-% transmission might be a cause for concern for high-Z beam with charge state losses in detectors/targets depending on the charge state distribution and how many charge states reach the S800 FP
-	Strategy for optimizing transmission
-	Want to balance losses between S800 analysis line and Transfer Hall (the S800 analysis line is typically slightly worse)
-	Best diagnostic is scalers from S800 FP, object scintillator and XF scintillator
-	Tweak y-quads (while watching scalers) in front of dipole gaps (this works both for Transfer Hall and analysis line); choose elements that have biggest effect with smallest ratio change
-	Matched optics
-	Typically much more time is invested for optimizing optics for matched optics than for focused optics
-	One input is optimizing for transmission
-	For tritons a scintillator is required at the pivot position since fragments at 5 Tm will not reach S800 FP
-	The last two analysis line triplets are used to tweak for the desired optical properties
-Document optimized transmission with another run to disk to measure rate of fragment of interest at S800 FP
-Reaction Settings and Coincidences
-Setting up Reaction Settings
-	Calculating reaction setting
-	Center unreacted beam at S800 FP
-	Adjust spectrograph Brho to center beam at S800 FP
-	Requirements for a beam to be “Centered”
-	Spectrograph dipoles matched
-	Beam position within about 1 cm of center as judges by 0 point on crdc1x spectrum or on track.xfp spectrum
-	Record run to disk to document centered unreacted beam setting
-	Calculate reaction setting using “effective” beam energy and the nominal target thickness
-	Ideally, experimenters should be the ones making this calculation
-	This approach assumes that the target thickness is known
-	Reaction setting to FP
-	Start with Attenuator setting of unreacted beam and step up in intensity
-	Set up beam blocker, if necessary
-	Expect to see unreacted beam if reaction setting is within +/- 3% of unreacted beam setting
-	Should have to move only one of the two blockers unless charge states are present
-	A graphic tool is available to help (not yet calibrated)
-	Try to cut only as much as necessary; depends on
-	What rate limits allow
-	What experimenters want (e.g., if they want singles, the cut has to be more restrictive to limit acquisition deadtime)
-	Move blocker, decrease attenuator, repeat
-Coincidences
-	Overview
-	Most experiments at the S800 involve setting up an auxiliary detector system (e.g. SeGA, HiRA, etc) to be used in coincidence with the standard detectors of the S800.
-	The auxiliary detector provides a secondary trigger that is fed into the S800 trigger system
-	A key part of setting up the S800 for such experiments is getting proper timing setup between the S800 and any auxiliary detectors
-	For cases where the Secondary detector has a slow response relative to the S800, the coincidence timing must be reset to the S800 timing by delaying the S800 trigger using the third gate and delay generator on the trigger GUI
-	A typical S800 delay for SeGA is 450 ns
-	Probably smaller typical S800 delay needed for HiRA
-	An example of experiments where auxiliary detectors are not used and, thus, setting up coincidence timing is not an issue are the experiments with tritons run by the charge exchange group
-	It is not clear whether coincidence setup gets logged as “XDT” or “EXR”
-	Choice of setting to be used for coincidence timing setup
-	The reaction of interest for the experiment can be used to setup coincidences only if the rate of coincidences is high enough
-	Sometime the pilot beam is used for setting up the coincidence timing in cases where the intensity of the secondary beam is too small
-	Example:  Reaction of interest 2p knockout to make Mg-36 from Si-38 (Si-38 rate was 1000 pps)
-	Setup
-	Coincidence signals are usually visible on scope without running scope in acquire mode
-	Adjust the width of the early signal (S800 or secondary) should be wide enough to catch coincidences with the late signal (width of late signal is not critical)
-	Readjust TDC delays based on changes made to S800 trigger delay
-	Experimenters will need to adjust their delays based on delay made to S800 trigger
-	Have experimenters record a run with coincidences on their account
-	S800 trigger TDC channel should show a peak (which corresponds to coincidences)
-	“secondary” TDC channel should have a peak
-	This check is required for verification in cases of low beam intensity (e.g. 1000 pps)
-	Length of run required is typically about 10-15 minutes
-	To be resolved:  whether or not to this run copied from experiment account for documentation of device tuning
-	Sample timing for running S800 with SeGA
-	SeGA trigger is late with respect to S800 trigger
-	Timing schematic to show how to
-	Setup of the S800 trigger to recover timing needed for proper functioning of S800 FP detectors
-	Set up the coincidence trigger
-	See:  http://groups.nscl.msu.edu/s800/Technical/Electronics/Electronics_frameset.htm
-	A double peak structure will appear in the TDC for the S800 trigger between the coincidence events and the singles events; the groups are separated by 25 ns because of the delay introduced by the downscaler used for the singles
-Followup
-	Before leaving beam with experimenters
-	Set up current trip points on Linux HV controls
-	Values used for K-48
-for CRDC and Ion Chamber anodes and intermediate image ppacs
-for CRDC drifts
-for IC drift
-	Ensure alarms are running
-	Make sure Linux HV GUI alarms are enabled
-	Make sure threshold on isobutane level is set up (not currently connected to alarms because they give too many false alarms when communication is lost)
-	All logs are being recorded
-	There is no log file for biases controlled by Labview
-	Linux HV
-	LabView gas handling system
-	Note in logbook
-	Scintillator biases
-	IC gate biases
-	Post reference printouts for experimenters
-	HV status:  a snapshot of HV GUI
-	Gas handling system status:  a snapshot of LabView window
-	Create window configuration with summing regions to make it easier for experimenters to track efficiency/performance of all detectors
-	Setting up coincidences for additional reaction settings in an experiment
-	Do not need to redo coincidence settup if secondary beam does not change
-	Might need to redo coincidence setup if secondary beam changes drastically
-	To watch during experiment
-	Look for isobutene running out – messes up data over several hours
-Experimenters responsibilities
-	Implementing dE- or TOF-based corrections is part of EXR
-More detail needed
-	Minimum rates required for coincidence setup
-	Selection of appropriate substitute reactions for coincidence setup
-	How to feel comfortable that there will not be a problem with FP detector gases running out
-	Starting alarms
-	Starting logging
-Not covered
-	Details of mask calibration
-	Details on implementing dE- and TOF-based corrections
@@ Line 1115: / Line 41: @@
-	Index
-	Introduction
-	Experiment Types
-	Experiment planning
-	NMR
-	Operations software (Barney, QTChan, BLkq...)
-	Tracking setup
-	Device Tunning  Process (Focus mode, Dispersion-matching mode, Reaction setting, Unreacted beam)
-	Mask calibration
-	Beam blocker use
-	Setting optimization (tweaks)
-	Electronics
-	DAQ
-	Analysis
-	Operation Environment System Overview
-	Dump Switches
-	Experiment preparation (S800 checklist prior to experiment)
-	Login strategy
-	Detectors (TPPACs, CRDCs, IC, OBJ_SCI, S800_SCI, Hodoscope)
-	Overview
-	HV
-	Gas Handling system
-	Vacuum control
-	Special considerations for each detector
-	Shimming OBJ
-	Replacing OBJ
-Advance preparations

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