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tuning_the_s800_xdt [2015/10/26 12:33] pereira [Timing setup] |
tuning_the_s800_xdt [2015/10/26 14:01] pereira |
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- | * Select SpecTcl window S800_TOF.win | + | * Select SpecTcl window |
- | | + | * The three columns correspond to the **RF-FP** ToF (left), |
- | * 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 | ||
* 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 | ||
+ | * The MTDC spectra should never be empty because the matching window is sufficiently wide (around 4000 ns) | ||
{{: | {{: | ||
- | * Although the ToF reference (" | + | * If necessary, adjust delays: |
- | * Before going to the ToF modules, the OBJ and XFP signals are sent to a CANBERRA CFD 454 CFD in data U6 from the data-U6 patch panel (OBJ: patch panel #54, XFP: patch panel #1). (The exception is the OBJ signal into the MTDC) | + | * Using the [[S800 DAQ tools# |
- | * MTDC: | + | * Select |
- | * Before getting into the MTDC, the OBJ, XFP, and E1 up signals | + | * Adjust the TDC delays of OBJ and XFP using the delay boxes connected to the CANBERRA |
- | * The OBJ signal into the MCFD comes directly from the detector via S3 patch panel #94 (i.e., there is no signal to check in data U6) | + | * Adjust |
- | * The XFP signal into the MCFD module comes from data-U6 patch panel #70, connected to the CANBERRA 454 CFD XFP output | + | * In principle, |
- | * SpecTcl calculates the OBJ-to-Focal-Plane and XFP-to-Focal-Plane ToFs by substracting | + | |
- | * The MTDC timing signals do not require external delay adjustments because | + | |
- | * Tennelec | + | |
- | * The OBJ **stop** signal | + | |
- | * The XFP **stop** signal to the " | + | |
- | * Phillips TDC: | + | ==== Checking Particle ID and rate at S800 FP ==== |
- | * The OBJ output signal from the CANBERRA 454 CFD is delayed with the low-noise delay boxes in data-U6, | + | |
- | * The XFP output signal from the CANBERRA 454 CFD is delayed with the low-noise delay boxes in data-U6, and sent to the TDC via patch panel #66 | + | |
- | * SpecTcl calculates the OBJ-to-Focal-Plane and XFP-to-Focal-Plane ToFs by substracting the E1 up time (channel 8) to the OBJ time (channel 14) and the XFP time (channel 15) | + | |
- | | + | * Select SpecTcl window **S800_PID.win** in directory **/ |
+ | | ||
+ | * The first (top) row corresponds | ||
+ | * 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 | ||
- | * 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 | + | |
- | | + | |
+ | * Determine | ||
+ | * 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 **/ | ||
+ | * 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 | ||
- | * 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 | ||
- | * See [[http:// | ||
- | * 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 ==== | + | ==== Analysis line classic PPAC setup (Focus optics only) ==== |
- | * 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) ==== | ||
* " | * " | ||
* Classic PPACs have rate limitations from pileups | * Classic PPACs have rate limitations from pileups | ||
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==== 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 | ||
* 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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=== 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 | ||
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=== Matched optics === | === Matched optics === | ||
+ | |||
* Typically much more time is invested for optimizing optics for matched optics than for focused optics | * Typically much more time is invested for optimizing optics for matched optics than for focused optics | ||
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==== 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 | ||
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==== 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. | ||
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====== Dispersion Matching tuning ====== | ====== 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, | 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, | ||