tuning_the_s800_xdt
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tuning_the_s800_xdt [2015/10/21 16:14] pereira |
tuning_the_s800_xdt [2015/10/26 13:21] pereira [Timing setup] |
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| ====== Focus Mode ====== | ====== Focus Mode ====== | ||
| For most of the experiments in the S800, the analysis line is run in focus mode. In this optics, the analysis line is achromatic, i.e. the dispersive position of the beam focused in the target area (pivot point) does not depend on the momentum. Thus, this mode provides the biggest momentum acceptance (4%). On the other hand, since the spectrograph focal plane is chromatic, the resolution is limited to about 1 part in 1000 in energy. | For most of the experiments in the S800, the analysis line is run in focus mode. In this optics, the analysis line is achromatic, i.e. the dispersive position of the beam focused in the target area (pivot point) does not depend on the momentum. Thus, this mode provides the biggest momentum acceptance (4%). On the other hand, since the spectrograph focal plane is chromatic, the resolution is limited to about 1 part in 1000 in energy. | ||
| + | |||
| ===== Unreacted beam ===== | ===== Unreacted beam ===== | ||
| In the first part of the XDT, the rigidity of the S800 is typically set to match the value of the fragment beam (selected in the A1900) after passing through the S800 target. This is where the term " | In the first part of the XDT, the rigidity of the S800 is typically set to match the value of the fragment beam (selected in the A1900) after passing through the S800 target. This is where the term " | ||
| - | === Send beam to FP === | + | ==== Send beam to FP ==== |
| * Ensure that the S800 spectrograph magnets are tuned to the right rigidity | * Ensure that the S800 spectrograph magnets are tuned to the right rigidity | ||
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| - | === Object scintillator setup === | + | ==== Object scintillator setup ==== |
| * Bias detector. Typical bias: **1200-1800 V** (up to 2200 V) | * Bias detector. Typical bias: **1200-1800 V** (up to 2200 V) | ||
| Line 64: | Line 65: | ||
| * Watch for no rate change on scaler display with a bias adjustment up or down of about 50-100 V | * Watch for no rate change on scaler display with a bias adjustment up or down of about 50-100 V | ||
| - | === FP scintillator setup === | + | ==== FP scintillator setup ==== |
| * Set trigger to “s800 trigger” | * Set trigger to “s800 trigger” | ||
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| - | === Ionization Chamber setup === | + | ==== Ionization Chamber setup ==== |
| * Gas should be [[Gas handling system# | * Gas should be [[Gas handling system# | ||
| Line 107: | Line 108: | ||
| - | === CRDCs setup === | + | ==== CRDCs setup ==== |
| * **[[hv bias#hv remote control|Bias]]** CRDCs | * **[[hv bias#hv remote control|Bias]]** CRDCs | ||
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| - | === Timing setup === | + | ==== Timing setup ==== |
| - | + | At present, there are three electronic " | |
| - | * See [[http://groups.nscl.msu.edu/ | + | |
| - | + | ||
| - | * The TDC delays | + | |
| - | * The “S800” trigger is from E1 up signal | ||
| - | * Trigger | + | * Select SpecTcl window **S800_TOF.win** |
| - | * There are 4 trigger inspect channels patched | + | * 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 second row corresponds to the MTDC with all the hits included | ||
| + | * The third row corresponds | ||
| + | * The fourth row corresponds to the ORTEC TACs. Note that there is not **RF-FP TAC** | ||
| + | * The two spectra in the fifth row corresponds | ||
| + | * 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 should never be empty because | ||
| - | * 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 | + | * If necessary, adjust delays: |
| - | * The signal delays controlled by the GUI (and not by cable delays) are not “pipelined” -– i.e., any new signals that arrive during | + | * Using ULM GUI assign TDC-start to one of the Inspect Trigger channels |
| - | * All of the trigger signals are not pipelined and are thus subject | + | * Select the timing signals (Delay inspect channels) E1 up, OBJ and XFP with the Delay GUI and look at them in the scope |
| + | * Adjust the TDC delays of OBJ and XFP using the delay boxes connected | ||
| + | * Adjust the TDC delays | ||
| + | * In principle, the TACs delays don't need to be adjusted | ||
| - | === Checking Particle ID and rate at S800 FP === | + | ==== Checking Particle ID and rate at S800 FP ==== |
| * Establish PID | * Establish PID | ||
| * Refer to information on setting from A1900 FP | * Refer to information on setting from A1900 FP | ||
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| - | === 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 215: | Line 217: | ||
| - | === Setup beamline === | + | ==== Setup beamline |
| * Object and XF scintillators and intermediate image PPACs inserted if they will be used | * 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 | * 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 | ||
| Line 221: | Line 223: | ||
| * Set spectrograph Brho for unreacted fragment | * Set spectrograph Brho for unreacted fragment | ||
| - | === Start scalers === | + | ==== Start scalers |
| * Use s800 account | * Use s800 account | ||
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| * scalers (gives error if no bridge) | * scalers (gives error if no bridge) | ||
| - | === Setting Optimization === | + | ==== Setting Optimization |
| === Focused optics === | === Focused optics === | ||
tuning_the_s800_xdt.txt · Last modified: 2023/09/22 15:15 by swartzj
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