tuning_the_s800_xdt
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tuning_the_s800_xdt [2015/10/26 12:41] pereira [Timing setup] |
tuning_the_s800_xdt [2015/10/26 14:09] pereira [Follow-up] |
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| * Select SpecTcl window **S800_TOF.win** | * Select SpecTcl window **S800_TOF.win** | ||
| - | * The three columns correspond to the RF-FP ToF (left), OBJ-FP (center), and XFP-FP (right) | + | * The three columns correspond to the **RF-FP** ToF (left), |
| * The first (top) row corresponds to the Phillips TDC | * The first (top) row corresponds to the Phillips TDC | ||
| * The second row corresponds to the MTDC with all the hits included | * The second row corresponds to the MTDC with all the hits included | ||
| * The third row corresponds to the MTDC with only the first hit | * The third row corresponds to the MTDC with only the first hit | ||
| - | * The fourth row corresponds to the ORTEC TACs. Note that there is not RF-FP TAC | + | * The fourth row corresponds to the ORTEC TACs. Note that there is not **RF-FP TAC** |
| * The two spectra in the fifth row corresponds to the MTDC summary spectra of OBJ-FP and XFP-FP ToFs (zoomed in). The spectra show the ToF (vertical axis) vs. hit number (horizontal axis). In an unreacted setting, one expects to see the most of the " | * The two spectra in the fifth row corresponds to the MTDC summary spectra of OBJ-FP and XFP-FP ToFs (zoomed in). The spectra show the ToF (vertical axis) vs. hit number (horizontal axis). In an unreacted setting, one expects to see the most of the " | ||
| * An empty ToF spectrum means that either the delays are not right (and need to be adjusted) or the spectrum range is too narrow | * An empty ToF spectrum means that either the delays are not right (and need to be adjusted) or the spectrum range is too narrow | ||
| Line 174: | Line 174: | ||
| {{: | {{: | ||
| - | * Adjust | + | * If necessary, adjust |
| - | * | + | * Using the [[S800 DAQ tools# |
| - | * | + | * Select the timing signals (Delay inspect channels) E1 up, OBJ and XFP with the [[S800 DAQ tools#Delay Window|Delay GUI]] and look at them in the scope |
| - | | + | * Adjust the TDC delays of OBJ and XFP using the delay boxes connected to the CANBERRA CFD 454 in data U6 |
| + | * Adjust the TDC delays of E1 up, down using the Delay GUI | ||
| + | * In principle, the TACs delays don't need to be adjusted | ||
| - | | + | ==== Checking Particle ID and rate at S800 FP ==== |
| + | |||
| + | * Select SpecTcl window **S800_PID.win** in directory **/user/s800/ | ||
| + | * The three columns correspond to the PID determined with the **RF-FP** ToF (left), **OBJ-FP** (center), and **XFP-FP** (right) | ||
| + | * The first (top) row corresponds to the Phillips TDC | ||
| + | * The second row corresponds to the MTDC with just the first hit included | ||
| + | * The third row corresponds to the ORTEC TACs. Note that there is not **RF-FP TAC** | ||
| + | * You might need to adjust the limits of the spectra to get a good resolution | ||
| + | |||
| + | {{: | ||
| + | |||
| + | |||
| + | * Establish PID and measure rate | ||
| + | * Determine the blob that corresponds to the unreacted beam (refer to information on setting from A1900 FP) | ||
| + | * Take gates around the fragment of interest | ||
| + | * Measure the beam intensity the appropriate faraday cup | ||
| + | * Take a run on disk | ||
| + | * Measure the beam intensity again and calculate the average value | ||
| + | * In [[s800 SpecTcl|SpecTcl GUI]], click **Attach to File** and select data file **run-xxxx-xx.evt** in directory **/user/s800/stagearea/experiment/runxxxx**, where xxxx stands | ||
| + | * Check the run time and live time from the corresponding scaler file in directory **/ | ||
| + | * Calculate the rate and purity and compare with the value in the A1900 FP to determine the transmission | ||
| - | * 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. | ||
| - | * 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) ==== | ==== Analysis line classic PPAC setup (Focus optics only) ==== | ||
| + | |||
| * " | * " | ||
| * Classic PPACs have rate limitations from pileups | * Classic PPACs have rate limitations from pileups | ||
| Line 234: | Line 235: | ||
| * 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. | * 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 ==== | ==== Setting Optimization ==== | ||
| === Focused optics === | === Focused optics === | ||
| + | |||
| * Expectations for A1900 FP to S800 FP transmission | * Expectations for A1900 FP to S800 FP transmission | ||
| * 80% or better for mid-Z fragments | * 80% or better for mid-Z fragments | ||
| Line 273: | Line 254: | ||
| - | === 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 | ||
| + | ====== Dispersion Matching tuning ====== | ||
| - | ===== Reaction Setting ===== | + | In the dispersion-matching optics, the S800 focal point is achromatic, i.e. the position of the beam in the dispersive direction does not depend on the momentum. As a consequence, |
| + | |||
| + | Charge-exchange experiments require typically this optics. In some cases, the beam used is < | ||
| + | |||
| + | * Set trigger to “s800 trigger” | ||
| + | * Ensure that the **[[s800 daq tools# | ||
| + | * Under trigger tab select **s800 trigger** (which is E1 up by definition) | ||
| + | * Deselect experiment trigger | ||
| + | * SAVE TO FILE | ||
| + | * Stop and start **[[s800 daq tools#Run Control Window|RunControl]]** to assert new trigger condition | ||
| + | |||
| + | * Select **[[s800 SpecTcl|Spectcl]]** window **S800_DISPMATCH.win** | ||
| + | | ||
| + | |||
| + | * We need to start checking the spectra showing the correlations between angle and position in both dispersive and non-dispersive directions. We typically use the spectrum **CRDC1.XG_CRDC1.TAC** for the non-dispersive direction, and **S800.FP.TRACK.XFP_TRACK.AFP** for the dispersive direction | ||
| + | | ||
| + | * The parabolas seen in the above spectra correspond to reactions with H in the target. The blurred lines on the right of the parabolas correspond to reaction with C. It is hard to see clearly this lines, so we need to make several gates | ||
| + | * Open spectrum **E1.DE_TOF.RF** and define a gate around < | ||
| + | | ||
| + | * This gate is used to fill spectra **S800.FP.TRACK.XFP_TRACK.AFP!FOI** and **CRDC1.XG_CRDC1.TAC!FOI**. As can be seen in the figures below, this gate " | ||
| + | | ||
| + | * Define rectangular gates in this spectra, making sure that it is narrow enough to select a vertical section of the parabolas, but wide enough to get enough statistics. Call them **afp** (in spectrum **CRDC1.XG_CRDC1.TAC!FOI**) and **bfp** (in spectrum **S800.FP.TRACK.XFP_TRACK.AFP!FOI**). After applying these new gates, the kinematics spectra are very clean | ||
| + | {{: | ||
| + | * The pre-defined gate **allgates** is made by the AND condition of all the gates defined above (**foi**, **afp**, and **bfp**). This gate is used to fill the spectrum **CRDC1.XG!FOI-AFP-BFP**, | ||
| + | | ||
| + | * The leftmost peak corresponds to reactions with H. The central peak are reaction with C. The goal of the tweak is to make these peaks as narrow as possible | ||
| + | * Open the NCS application **QtKM** in the Applications Menu. Open file **BLSetup_A1900.gkm**. The magnetic elements that are typically tweaked with the knob box seating on the left side of u6pc5 are **I232TA**, **I236TC**, and **I245TC** which can be found on page **S800 BLine+Spectrograph**. Other elements used to improve the focusing in the object point, and the transmission are **I172QA** and **I174QB**. The goal of the dispersion-matching tuning is to find a compromise between transmission and resolution. | ||
| + | | ||
| + | * The two figures below show the spectrum **CRDC1.XG!FOI-AFP-BFP** before (top) and after (bottom) the dispersion-matching tuning for a typical experiment. Be aware that the width given by SpecTcl for the selected peak is not too reliable. It is more convenient to do a real gaussian fit. Unfortunatelly this is not an option included in the current version of SpecTcl. That's why some device physicists prefer SpecTk for this type of tuning | ||
| + | {{: | ||
| + | |||
| + | |||
| + | ====== Reaction Setting | ||
| + | |||
| + | ===== Setting up Reaction Settings ====== | ||
| - | ==== Setting up Reaction Settings ==== | ||
| * Calculating reaction setting | * Calculating reaction setting | ||
| * Center unreacted beam at S800 FP | * Center unreacted beam at S800 FP | ||
| Line 311: | Line 320: | ||
| * Move blocker, decrease attenuator, repeat | * Move blocker, decrease attenuator, repeat | ||
| - | ==== Coincidences ==== | + | |
| + | |||
| + | |||
| + | |||
| + | ===== Coincidences ===== | ||
| * Overview | * 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. | * 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. | ||
| Line 352: | Line 366: | ||
| {{: | {{: | ||
| - | |||
| - | |||
| - | ===== Follow-up ===== | ||
| - | |||
| - | * Before leaving beam with experimenters | ||
| - | * Set up current trip points on Linux HV controls | ||
| - | * Values used for K-48 | ||
| - | * 5 for CRDC and Ion Chamber anodes and intermediate image ppacs | ||
| - | * 50 for CRDC drifts | ||
| - | * 80 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/ | ||
| - | |||
| - | * 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 | ||
| - | |||
| - | * 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 | ||
| - | |||
| - | |||
| - | |||
| - | ====== Dispersion Matching tuning ====== | ||
| - | In the dispersion-matching optics, the S800 focal point is achromatic, i.e. the position of the beam in the dispersive direction does not depend on the momentum. As a consequence, | ||
| - | |||
| - | Charge-exchange experiments require typically this optics. In some cases, the beam used is < | ||
| - | |||
| - | * Set trigger to “s800 trigger” | ||
| - | * Ensure that the **[[s800 daq tools# | ||
| - | * Under trigger tab select **s800 trigger** (which is E1 up by definition) | ||
| - | * Deselect experiment trigger | ||
| - | * SAVE TO FILE | ||
| - | * Stop and start **[[s800 daq tools#Run Control Window|RunControl]]** to assert new trigger condition | ||
| - | |||
| - | * Select **[[s800 SpecTcl|Spectcl]]** window **S800_DISPMATCH.win** | ||
| - | | ||
| - | |||
| - | * We need to start checking the spectra showing the correlations between angle and position in both dispersive and non-dispersive directions. We typically use the spectrum **CRDC1.XG_CRDC1.TAC** for the non-dispersive direction, and **S800.FP.TRACK.XFP_TRACK.AFP** for the dispersive direction | ||
| - | | ||
| - | * The parabolas seen in the above spectra correspond to reactions with H in the target. The blurred lines on the right of the parabolas correspond to reaction with C. It is hard to see clearly this lines, so we need to make several gates | ||
| - | * Open spectrum **E1.DE_TOF.RF** and define a gate around < | ||
| - | | ||
| - | * This gate is used to fill spectra **S800.FP.TRACK.XFP_TRACK.AFP!FOI** and **CRDC1.XG_CRDC1.TAC!FOI**. As can be seen in the figures below, this gate " | ||
| - | | ||
| - | * Define rectangular gates in this spectra, making sure that it is narrow enough to select a vertical section of the parabolas, but wide enough to get enough statistics. Call them **afp** (in spectrum **CRDC1.XG_CRDC1.TAC!FOI**) and **bfp** (in spectrum **S800.FP.TRACK.XFP_TRACK.AFP!FOI**). After applying these new gates, the kinematics spectra are very clean | ||
| - | {{: | ||
| - | * The pre-defined gate **allgates** is made by the AND condition of all the gates defined above (**foi**, **afp**, and **bfp**). This gate is used to fill the spectrum **CRDC1.XG!FOI-AFP-BFP**, | ||
| - | | ||
| - | * The leftmost peak corresponds to reactions with H. The central peak are reaction with C. The goal of the tweak is to make these peaks as narrow as possible | ||
| - | * Open the NCS application **QtKM** in the Applications Menu. Open file **BLSetup_A1900.gkm**. The magnetic elements that are typically tweaked with the knob box seating on the left side of u6pc5 are **I232TA**, **I236TC**, and **I245TC** which can be found on page **S800 BLine+Spectrograph**. Other elements used to improve the focusing in the object point, and the transmission are **I172QA** and **I174QB**. The goal of the dispersion-matching tuning is to find a compromise between transmission and resolution. | ||
| - | | ||
| - | * The two figures below show the spectrum **CRDC1.XG!FOI-AFP-BFP** before (top) and after (bottom) the dispersion-matching tuning for a typical experiment. Be aware that the width given by SpecTcl for the selected peak is not too reliable. It is more convenient to do a real gaussian fit. Unfortunatelly this is not an option included in the current version of SpecTcl. That's why some device physicists prefer SpecTk for this type of tuning | ||
| - | {{: | ||
tuning_the_s800_xdt.txt · Last modified: 2023/09/22 15:15 by swartzj
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