Difference between revisions of "Beam Test Meeting Mon. May. 07, 2012"
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| + | # Planning for down time on Wednesday | ||
| + | #* Remove pair spectrometer prototype from Hall (current in 60% position) | ||
| + | #* Move Hall A prototype from 35% to 60% position | ||
| + | #* Move Bcal prototype from 22% to 35% position | ||
| + | #* Move Fcal prototype from 5% to 22% position | ||
# Preliminary look at pulse heights and times (Elton) | # Preliminary look at pulse heights and times (Elton) | ||
#* [[Media:Run491 histos.pdf]] Run 491 (Vbr=0.9 V) | #* [[Media:Run491 histos.pdf]] Run 491 (Vbr=0.9 V) | ||
#* [[Media:Run498 histos.pdf]] Run 498 (Vbr=1.2 V) | #* [[Media:Run498 histos.pdf]] Run 498 (Vbr=1.2 V) | ||
| + | # What gains do we want to run at? | ||
| + | #* Gain Ratio (from Andrei's plot): Vbr=0.9/Vbr=1.2 = 1800/2500 = 0.72 | ||
| + | #* Maximum ADC from downstream ch2 R491/R498 = 3300/4000 = 0.83 | ||
| + | #[https://halldweb.jlab.org/wiki/images/c/c3/Fcal_range_484.ps FADC range from Run 484: Vbr=1.2V] (Andrei) | ||
| + | # Bcal data to be taken | ||
| + | #* TDC threshold scan | ||
| + | #* Vover=1.2 V, 4 files 80k each, nominal TDC threshold | ||
| + | #* Vover=0.9 V, 4 files 80k each, nominal TDC threshold | ||
| + | #* Vover=1.2 V, 4 files 80k each, 1/2 TDC threshold | ||
| + | #* Vover=0.9 V, 4 files 80k each, 1/2 TDC threshold | ||
| + | #* Vover=1.2 V, 4 files 80k each, 1/4 TDC threshold | ||
| + | #* Vover=0.9 V, 4 files 80k each, 1/4 TDC threshold | ||
| + | # Considerations in choosing the SiPM operating voltage (Notes by Elton) | ||
| + | #* PDE increases with overbias (favors 1.2 V) | ||
| + | #* Noise increases with overbias (favors 0.9 V) | ||
| + | #* Higher voltage decreases sensitivity to absolute bias voltage setting (favors 1.2 V) | ||
| + | #* Gain increases with overbias, relaxing the electronic gain requirements (favors 1.2 V) | ||
| + | |||
| + | |||
| + | == Minutes == | ||
| + | |||
| + | FCAL | ||
| + | |||
| + | - time extraction mode still broken, hope to fix soon | ||
| + | |||
| + | - data taken at 7 degrees lower than nominal alignment | ||
| + | |||
| + | BCAL | ||
| + | |||
| + | - see above and logbook for more details | ||
| + | |||
| + | - data taking at 20 degree point complete | ||
| + | |||
| + | - will fix upstream electronics during beam studies on Wednesday | ||
| + | |||
| + | Overall | ||
| + | |||
| + | - will slide all detectors down 1 energy position on Wednesday | ||
| + | |||
| + | - FCAL to 22.8 %, BCAL to 35 %, Hall A to 50 %, pair spectrometer out | ||
Latest revision as of 10:30, 31 March 2015
- Planning for down time on Wednesday
- Remove pair spectrometer prototype from Hall (current in 60% position)
- Move Hall A prototype from 35% to 60% position
- Move Bcal prototype from 22% to 35% position
- Move Fcal prototype from 5% to 22% position
- Preliminary look at pulse heights and times (Elton)
- Media:Run491 histos.pdf Run 491 (Vbr=0.9 V)
- Media:Run498 histos.pdf Run 498 (Vbr=1.2 V)
- What gains do we want to run at?
- Gain Ratio (from Andrei's plot): Vbr=0.9/Vbr=1.2 = 1800/2500 = 0.72
- Maximum ADC from downstream ch2 R491/R498 = 3300/4000 = 0.83
- FADC range from Run 484: Vbr=1.2V (Andrei)
- Bcal data to be taken
- TDC threshold scan
- Vover=1.2 V, 4 files 80k each, nominal TDC threshold
- Vover=0.9 V, 4 files 80k each, nominal TDC threshold
- Vover=1.2 V, 4 files 80k each, 1/2 TDC threshold
- Vover=0.9 V, 4 files 80k each, 1/2 TDC threshold
- Vover=1.2 V, 4 files 80k each, 1/4 TDC threshold
- Vover=0.9 V, 4 files 80k each, 1/4 TDC threshold
- Considerations in choosing the SiPM operating voltage (Notes by Elton)
- PDE increases with overbias (favors 1.2 V)
- Noise increases with overbias (favors 0.9 V)
- Higher voltage decreases sensitivity to absolute bias voltage setting (favors 1.2 V)
- Gain increases with overbias, relaxing the electronic gain requirements (favors 1.2 V)
Minutes
FCAL
- time extraction mode still broken, hope to fix soon
- data taken at 7 degrees lower than nominal alignment
BCAL
- see above and logbook for more details
- data taking at 20 degree point complete
- will fix upstream electronics during beam studies on Wednesday
Overall
- will slide all detectors down 1 energy position on Wednesday
- FCAL to 22.8 %, BCAL to 35 %, Hall A to 50 %, pair spectrometer out
