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tuning_the_s800_xdt [2015/10/26 14:11] pereira [Analysis line classic PPAC setup (Focus optics only)] |
tuning_the_s800_xdt [2017/04/08 13:40] pereira [FP scintillator setup] |
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* Expected " | * Expected " | ||
- | * Ensure that CRAD04 | + | * Ensure that CRAD04 is enabled with a rate limit of **20 kHz** (CRAD04 looks at E1 up FP scintillator) |
* Remember: S800 FP rate limit is **6 kHz** | * Remember: S800 FP rate limit is **6 kHz** | ||
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* Adjust MCFD threshold: | * Adjust MCFD threshold: | ||
- | * Open configuration file **MCFD16.tcl** in **/user/s800/ | + | * Using the [[s800 daq tools# |
* The OBJ signal feeding this module is not patched out to data U6 | * The OBJ signal feeding this module is not patched out to data U6 | ||
- | * The OBJ signal from MCFD-16 module goes to the Mesytec | + | * The OBJ signal from MCFD module goes to the Mesytec |
* Make sure that the threshold of the XFP MCFD channel is reasonable. Rates in scaler channels XFP.Scint and XFP.MCFD.Scint should be comparable | * Make sure that the threshold of the XFP MCFD channel is reasonable. Rates in scaler channels XFP.Scint and XFP.MCFD.Scint should be comparable | ||
* Adjust MCFD OBJ threshold looking at scalers. The ratio of OBJ to XFP scaler rates (channels OBJ.MCFD.Scint and XFP.MCFD.Scint) should reflect the transmission of the cocktail beam | * Adjust MCFD OBJ threshold looking at scalers. The ratio of OBJ to XFP scaler rates (channels OBJ.MCFD.Scint and XFP.MCFD.Scint) should reflect the transmission of the cocktail beam | ||
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* Set trigger to “s800 trigger” | * Set trigger to “s800 trigger” | ||
- | * Ensure that the **[[s800 daq tools# | + | * Ensure that the **[[s800 daq tools# |
* Under trigger tab select **s800 trigger** (which is E1 up by definition) | * Under trigger tab select **s800 trigger** (which is E1 up by definition) | ||
* Deselect experiment trigger | * Deselect experiment trigger | ||
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* End and Begin **[[s800 daq tools#Run Control Window|ReadoutGUI]]** to assert new trigger condition | * End and Begin **[[s800 daq tools#Run Control Window|ReadoutGUI]]** to assert new trigger condition | ||
- | * Select **[[s800 SpecTcl|Spectcl]]** window **S800_SCINT.win** | + | * Select **[[s800 SpecTcl|Spectcl]]** window **S800_SCINT.win** |
* Adjust **[[hv bias|bias]]** looking at 2D spectra **e1.deup_e1.dedown** (showing the parameters s800.fp.e1.de_down vs. s800.fp.e1.de_up) for the FP E1 scintillator | * Adjust **[[hv bias|bias]]** looking at 2D spectra **e1.deup_e1.dedown** (showing the parameters s800.fp.e1.de_down vs. s800.fp.e1.de_up) for the FP E1 scintillator | ||
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- | * Select **[[s800 SpecTcl|Spectcl]]** window **S800_IC.win** | + | * Select **[[s800 SpecTcl|Spectcl]]** window **S800_IC.win** |
* Adjust pad gains | * Adjust pad gains | ||
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* They correspond to the non-dispersive position of the beam in the CRDCs. | * They correspond to the non-dispersive position of the beam in the CRDCs. | ||
- | {{: | + | {{: |
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* 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), **OBJ-FP** (center), and **XFP-FP** (right) | ||
* 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. Note that in a unreacted-beam setting, the first hit typically provides the " |
* 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). | + | * 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). |
* 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 | ||
- | * The MTDC spectra | + | * The MTDC delays |
{{: | {{: | ||
+ | |||
+ | * Due to the multi-hit capability of the MTDC, we need to select the " | ||
+ | * Use the spectra **TOF.MTDC_RF**, | ||
+ | * Using the cursor mouse, check the lower and higher limits defining the region in the MTDC ToF spectra with the " | ||
+ | * Go to the **Variables** page in SpecTcl GUI and assign the limits to the following variables: | ||
+ | * **s800.fp.vmetdc.mtdc_rflow** and **s800.fp.vmetdc.mtdc_rfhigh** for RF-XFP | ||
+ | * **s800.fp.vmetdc.mtdc_objlow** and **s800.fp.vmetdc.mtdc_objhigh** for OBJ-XFP | ||
+ | * **s800.fp.vmetdc.mtdc_xfplow** and **s800.fp.vmetdc.mtdc_xfphigh** for XFP-XFP | ||
+ | * For each ToF, SpecTcl will search the hit number that fits in the selected region. The new MTDC ToF parameters are **s800.fp.vmetdc.mtdc_rf**, | ||
* If necessary, adjust delays: | * If necessary, adjust delays: | ||
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* Adjust the TDC delays of E1 up, down using the Delay GUI | * Adjust the TDC delays of E1 up, down using the Delay GUI | ||
* In principle, the TACs delays don't need to be adjusted | * In principle, the TACs delays don't need to be adjusted | ||
+ | |||
+ | |||
+ | * Check the efficiencies of the Phillips TDC, TACs, and MTDC for the OBJ-FP and XFP-FP ToFs: | ||
+ | * Make a gate on spectrum **IC.SUM** selecting the region of interest, and call it " | ||
+ | * Looking at the ToF spectra gated on " | ||
+ | * The window file **S800_TOF_EFFICIENCY.win** includes all the spectra needed | ||
==== Checking Particle ID and rate at S800 FP ==== | ==== Checking Particle ID and rate at S800 FP ==== | ||
- | * Select SpecTcl window **S800_PID.win** in directory **/ | + | * Select SpecTcl window **S800_PID.win** |
* The three columns correspond to the PID determined with the **RF-FP** ToF (left), **OBJ-FP** (center), and **XFP-FP** (right) | * 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 first (top) row corresponds to PID spectra using the Phillips TDC |
- | * The second row corresponds to the MTDC with just the first hit included | + | * The second row corresponds to PID spectra using the MTDC with __just |
- | * The third row corresponds to the ORTEC TACs. Note that there is not **RF-FP TAC** | + | * The third row corresponds to PID spectra using the MTDC including the correct hit corresponding to the good ToF peak (see previous section) |
+ | * The fourth row corresponds to PID spectra using the MTDC gated on the " | ||
+ | * The fifth row corresponds to PID spectra using 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 | * You might need to adjust the limits of the spectra to get a good resolution | ||
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* Establish PID and measure rate | * Establish PID and measure rate | ||
- | * Determine | + | * Choose your favorite PID spectrum and determine |
* Take gates around the fragment of interest | * Take gates around the fragment of interest | ||
* Measure the beam intensity the appropriate faraday cup | * Measure the beam intensity the appropriate faraday cup | ||
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==== Setting Optimization ==== | ==== Setting Optimization ==== | ||
- | |||
- | === Focused optics === | ||
* Expectations for A1900 FP to S800 FP transmission | * Expectations for A1900 FP to S800 FP transmission | ||
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* Want to balance losses between S800 analysis line and Transfer Hall (the S800 analysis line is typically slightly worse) | * 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 | * 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 | + | * Using the knob box and the NCS application **QtKM** (file **BLSetup_A1900.gkm**), |
* Document optimized transmission with another run to disk to measure rate of fragment of interest at S800 FP | * Document optimized transmission with another run to disk to measure rate of fragment of interest at S800 FP | ||
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- | ====== Dispersion Matching | + | ====== Dispersion Matching |
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, | 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, | ||
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| | ||
* 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 | * 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 | + | * 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 sitting |
| | ||
* 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 | * 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 | ||
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* Reaction setting to FP | * Reaction setting to FP | ||
* Start with Attenuator setting of unreacted beam and step up in intensity | * Start with Attenuator setting of unreacted beam and step up in intensity | ||
- | * Set up beam blocker, | + | * If necessary, set up beam blocker |
+ | * Click on label **I255 Slits** in the S3 page of Barney | ||
+ | * Expected " | ||
* Expect to see unreacted beam if reaction setting is within +/- 3% of unreacted beam setting | * 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 | * 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 | * Try to cut only as much as necessary; depends on | ||
* What rate limits allow | * What rate limits allow | ||
* What experimenters want (e.g., if they want singles, the cut has to be more restrictive to limit acquisition deadtime) | * 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 | * Move blocker, decrease attenuator, repeat | ||
+ | |||
+ | * If necessary, do the ToF corrections to improve the PID resolution (instructions [[During experiments# | ||
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* Probably smaller typical S800 delay needed for HiRA | * 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 | * 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 | * 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 | * The reaction of interest for the experiment can be used to setup coincidences only if the rate of coincidences is high enough | ||
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- | |||
- | |||
- | ====== 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 | ||