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--- preparation_for_tuning_the_s800 [2013/12/13 20:53]
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+++ preparation_for_tuning_the_s800 [2015/10/27 09:32] (current)
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 ====== Preparation for tuning ======
-  * [[Software|Software overview]]
+  * [[To-Do list]]
+  * [[Software|Computers and Software]]
+  * [[S800 DAQ tools]]
   * [[Electronics overview|Electronics, patch panels, and hardware]]
+  * [[Vacuum control]]
   * [[Gas handling system]]
   * [[HV bias]]
@@ Line 9: / Line 12: @@
-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

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