Difference between revisions of "Tracking Meeting Mar 14 2025 2:30PM ET"
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Back to [[Main_Page|Main Page]] >> [[Tracking system | Tracking system]] | Back to [[Main_Page|Main Page]] >> [[Tracking system | Tracking system]] | ||
| − | >> [[ | + | >> [[ Tracking_Meeting_Mar_28_2025_2:30PM_ET| following meeting]] |
>> [[ Tracking_Meeting_Feb_28_2025_2:30PM_ET| previous meeting]] | >> [[ Tracking_Meeting_Feb_28_2025_2:30PM_ET| previous meeting]] | ||
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=Agenda= | =Agenda= | ||
| − | * (Rakitha) - | + | * (Rakitha) - Trigger Scintillator |
* (Jaydeep, James, brynna) SBU GEMs | * (Jaydeep, James, brynna) SBU GEMs | ||
| − | |||
* (Huong, Nilanga) - UVA GEMs | * (Huong, Nilanga) - UVA GEMs | ||
| − | * (Asar) - | + | * (Asar) - JLab Cosmic testing |
| + | * (David) - Rotator | ||
=Attendance= | =Attendance= | ||
| − | + | Vidura, Rakitha, David Nilanga, Shashini, Chandan, Carl, Lasitha, Huong, Asar, Jaydeep | |
=Minutes= | =Minutes= | ||
| + | |||
| + | #(Rakitha): Trigger scintillator time resolution - tried to measure using 'scope to measure delta_T between paddle coincidence time and signal from TS. Spectrum looks a bit strange - see uploaded figure: https://moller.jlab.org/wiki/index.php/File:Side_Postion_3_13_25Scope_dT_800_3.png . With 1 ns wide bins, see a big peak that is one channel wide, two side peaks that are one channel wide at +10 ns and -10 ns, and some "grass" around the main peak. The +-10 ns stuff must be some sort of artifact of the 'scope digitization. While the peak in a 1 ns wide bin is very promising, need to verify with a better understood system. Decide that LaTech while ship the first production module to W&M, and then we will test it in the pion detector cosmic setup at Jlab. We can also do mechanical test fits in the prototype GEM/TS frame. | ||
| + | #(David): Rotator - parts for prototype GEM/TS frame have been ordered, and some have already arrived (https://dilbert.physics.wm.edu/GEM+Rotator/18). Procurement of the linear actuators, stepper drives, and non-magnetic linear guides is underway - need to sole-source, so this takes a bit of time. Now concern - the max crane-hook height in Small Hall High Bay too low for obvious way to lift the Ferris wheel rings onto the stand. Unlikely that we can get JLab Test Lab space to do this. May need a clever lifting rig solution. | ||
| + | #(Nilanga): confirms that Asar is the right person to work with David on test-installing UVa GEMs into prototype frame. | ||
| + | #(Jaydeep): SBU Has completed 5 production GEMs, and is busy testing them, before bringing to JLab (early April). Had some noise issues with APVs - need Faraday cage to suppress. Initial cosmic efficiency plateau only seems to reach 88% efficiency. Latency is fine. USing SRS system. However the three scintillator paddles are all on one side of the GEM (each TS is smaller in area than the GEM), no Pb to harden the comsic spectrum - may have spurious triggers. Suspect that the actually plateau efficiency is probably closer to 95%. Note that present SBU resistive divider is such that expect max. voltage around 3650 V. Also, have been using 25 sigma cut (sigma = sigma of pedestal) for real hits - this may be too stringent; the noise that is cutis almost all 1 time-step in length. A cut based on requiring multiple sequential time-steps above a lower threshold may be enough. | ||
| + | #(Asar): present cosmic setup has 2 MOLLER production GEMs, SBS xy GEM layer, and prototype MOLLER GEM (wrong readout); added another SBS GEM to the stack in last few days. | ||
| + | #(Chandan): initial tracking analysis of cosmic data is promising; Asar suggestsnot using the prototype with the older readout in the alignment script, but just as a software trgger. Chandan working to align the chambers relative to the SBS layer. May need more statistics to get good alignments. Note that the UVA prototype is not mechanically identical to production GEMs, so can't use that one as "sacrificial lanb" for test fitting in GEM/TS frame. | ||
| + | #(Carl): Suggestion for storage shelf units for GEMs at JLab, after they are tested. This seems fine to everyone - probably want about 10" gap between layers for ease of removal of GEMs from shelf. | ||
| + | #(David): we need to make sure we can add a Faraday cage shielding for MOLLER GEMs, similar to what was needed for SBS GEMs, as we will probably need to suppress rf noise in the Hall. | ||
Latest revision as of 18:46, 16 March 2025
Back to Main Page >> Tracking system
Zoom link: Please contact David Armstrong for meeting coordinates, or check with the MOLLER meeting calendar.
Agenda
- (Rakitha) - Trigger Scintillator
- (Jaydeep, James, brynna) SBU GEMs
- (Huong, Nilanga) - UVA GEMs
- (Asar) - JLab Cosmic testing
- (David) - Rotator
Attendance
Vidura, Rakitha, David Nilanga, Shashini, Chandan, Carl, Lasitha, Huong, Asar, Jaydeep
Minutes
- (Rakitha): Trigger scintillator time resolution - tried to measure using 'scope to measure delta_T between paddle coincidence time and signal from TS. Spectrum looks a bit strange - see uploaded figure: https://moller.jlab.org/wiki/index.php/File:Side_Postion_3_13_25Scope_dT_800_3.png . With 1 ns wide bins, see a big peak that is one channel wide, two side peaks that are one channel wide at +10 ns and -10 ns, and some "grass" around the main peak. The +-10 ns stuff must be some sort of artifact of the 'scope digitization. While the peak in a 1 ns wide bin is very promising, need to verify with a better understood system. Decide that LaTech while ship the first production module to W&M, and then we will test it in the pion detector cosmic setup at Jlab. We can also do mechanical test fits in the prototype GEM/TS frame.
- (David): Rotator - parts for prototype GEM/TS frame have been ordered, and some have already arrived (https://dilbert.physics.wm.edu/GEM+Rotator/18). Procurement of the linear actuators, stepper drives, and non-magnetic linear guides is underway - need to sole-source, so this takes a bit of time. Now concern - the max crane-hook height in Small Hall High Bay too low for obvious way to lift the Ferris wheel rings onto the stand. Unlikely that we can get JLab Test Lab space to do this. May need a clever lifting rig solution.
- (Nilanga): confirms that Asar is the right person to work with David on test-installing UVa GEMs into prototype frame.
- (Jaydeep): SBU Has completed 5 production GEMs, and is busy testing them, before bringing to JLab (early April). Had some noise issues with APVs - need Faraday cage to suppress. Initial cosmic efficiency plateau only seems to reach 88% efficiency. Latency is fine. USing SRS system. However the three scintillator paddles are all on one side of the GEM (each TS is smaller in area than the GEM), no Pb to harden the comsic spectrum - may have spurious triggers. Suspect that the actually plateau efficiency is probably closer to 95%. Note that present SBU resistive divider is such that expect max. voltage around 3650 V. Also, have been using 25 sigma cut (sigma = sigma of pedestal) for real hits - this may be too stringent; the noise that is cutis almost all 1 time-step in length. A cut based on requiring multiple sequential time-steps above a lower threshold may be enough.
- (Asar): present cosmic setup has 2 MOLLER production GEMs, SBS xy GEM layer, and prototype MOLLER GEM (wrong readout); added another SBS GEM to the stack in last few days.
- (Chandan): initial tracking analysis of cosmic data is promising; Asar suggestsnot using the prototype with the older readout in the alignment script, but just as a software trgger. Chandan working to align the chambers relative to the SBS layer. May need more statistics to get good alignments. Note that the UVA prototype is not mechanically identical to production GEMs, so can't use that one as "sacrificial lanb" for test fitting in GEM/TS frame.
- (Carl): Suggestion for storage shelf units for GEMs at JLab, after they are tested. This seems fine to everyone - probably want about 10" gap between layers for ease of removal of GEMs from shelf.
- (David): we need to make sure we can add a Faraday cage shielding for MOLLER GEMs, similar to what was needed for SBS GEMs, as we will probably need to suppress rf noise in the Hall.
