tuning_the_s800_xdt
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tuning_the_s800_xdt [2015/10/26 14:07] pereira [Setting up Reaction Settings] |
tuning_the_s800_xdt [2015/10/29 09:57] pereira [Checking Particle ID and rate at S800 FP] |
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| Line 18: | Line 18: | ||
| * 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** | ||
| Line 55: | Line 55: | ||
| * 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 | ||
| Line 74: | Line 74: | ||
| * 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** in directory **/ |
| * 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 | ||
| Line 94: | Line 94: | ||
| - | * Select **[[s800 SpecTcl|Spectcl]]** window **S800_IC.win** | + | * Select **[[s800 SpecTcl|Spectcl]]** window **S800_IC.win** |
| * Adjust pad gains | * Adjust pad gains | ||
| Line 126: | Line 127: | ||
| * Count rate is a little higher than on scintillator due to noise or thresholds | * Count rate is a little higher than on scintillator due to noise or thresholds | ||
| - | * Check **[[s800 SpecTcl|Spectcl]]** window **S800_CRDCS.win** (see figure below) to verify the good performance of the detectors. (The spectra for each CRDC can be checked separatelly in windows **s800_CRDC1.win** and **S800_CRDC2.win**) | + | * Check **[[s800 SpecTcl|Spectcl]]** window **S800_CRDCS.win** in directory **/ |
| * Spectra **crdc1.raws** and **crdc2.raws** (top and middle spectra in the leftmost (first) column) | * Spectra **crdc1.raws** and **crdc2.raws** (top and middle spectra in the leftmost (first) column) | ||
| Line 155: | Line 156: | ||
| * 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. | ||
| - | {{: | + | {{: |
| Line 186: | Line 187: | ||
| * Select SpecTcl window **S800_PID.win** in directory **/ | * Select SpecTcl window **S800_PID.win** in directory **/ | ||
| * 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 gated on the " |
| + | * The fourth 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 | ||
| Line 214: | Line 216: | ||
| ==== Analysis line classic PPAC setup (Focus optics only) ==== | ==== Analysis line classic PPAC setup (Focus optics only) ==== | ||
| + | **THIS SECTION IS STILL IN PROGRESS** | ||
| * " | * " | ||
| Line 237: | Line 240: | ||
| ==== Setting Optimization ==== | ==== Setting Optimization ==== | ||
| - | |||
| - | === Focused optics === | ||
| * Expectations for A1900 FP to S800 FP transmission | * Expectations for A1900 FP to S800 FP transmission | ||
| Line 248: | Line 249: | ||
| * 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 | ||
| Line 254: | Line 255: | ||
| - | ===== Reaction Setting ===== | ||
| - | ==== Coincidences ==== | + | |
| + | |||
| + | |||
| + | ====== Dispersion Matching Mode ====== | ||
| + | |||
| + | 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 sitting 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 ====== | ||
| + | |||
| + | * 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 | ||
| + | * If necessary, set up beam blocker looking at **CRDC1.RAWS** and/or **CRDC2.RAWS** SpecTcl spectra (see **S800_CRDCS.win** SpecTcl window shown above) | ||
| + | * 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 | ||
| + | * Should have to move only one of the two blockers unless charge states are present | ||
| + | * 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 | * Overview | ||
| Line 267: | Line 336: | ||
| * 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 | ||
| Line 301: | Line 369: | ||
| - | ===== 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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