This shows you the differences between two versions of the page.
Both sides previous revision Previous revision Next revision | Previous revision Next revision Both sides next revision | ||
tuning_the_s800_xdt [2015/10/26 14:09] pereira [Setting up Reaction Settings] |
tuning_the_s800_xdt [2015/10/27 14:24] pereira [Setting up Reaction Settings] |
||
---|---|---|---|
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 214: | Line 214: | ||
==== 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 238: | ||
==== 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 247: | ||
* 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 258: | Line 257: | ||
- | ===== Follow-up ===== | ||
- | * Before leaving beam with experimenters | + | ====== Dispersion Matching |
- | * 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 | + | |
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, | ||
Line 328: | Line 286: | ||
| | ||
* 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 | ||
Line 352: | Line 310: | ||
* 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 | + | * Looking at **CRDC1.RAWS** and/or **CRDC2.RAWS** SpecTcl spectra (shown in **S800_CRDCS.WIN**), |
+ | * 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 | ||
Line 375: | Line 333: | ||
* 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 406: | Line 363: | ||
{{: | {{: | ||
+ | |||
+ | |||
+ | |||
+ | |||
+ | |||
+ | ====== 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 | ||