Difference between revisions of "JEF meeting, February 12, 2021"
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* Data analysis | * Data analysis | ||
* Simulations | * Simulations | ||
| + | |||
| + | ==Minutes== | ||
| + | Attendees: Igal,Zisis,Phil,Sasha,Jared,Arsak,Tim B.,Tim W.,Liping,Jane,S.T. | ||
| + | * Attempts to communicate with our contact at SICCAS have failed | ||
| + | ** Still expecting a batch from SICCAS: wait for 1-2 weeks while keep trying to contact the company | ||
| + | ** Have money to spend on more crystals -- switch to CRYTUR? | ||
| + | * Sasha reported on linearity studies of amplifier used in redesigned PMT base | ||
| + | ** During PrimeX run observed nonlinear behavior that was reduced when reduced gain and increased HV | ||
| + | *** Bypassed the amplifier -> good performance | ||
| + | *** Beam tests: used 24x amplifier: very nonlinear! | ||
| + | ** Vlad P. worked on redesign: resistor changes to increase voltage on first dynode, addition of amplifier circuitry | ||
| + | ** Sasha used HP pulse generator to mimic current source, studied amplifier with ~2.3x gain | ||
| + | *** Gain drops off by ~10% below 0.5 V signal size, but stable at ~1-2% level above 0.5 V | ||
| + | **** Important because central block gets most of energy in the shower (~80%) | ||
| + | *** Linearity depends on HV, better linearity at higher divider currents | ||
| + | *** Nominal HV=900 V | ||
| + | ** Ideas to improve base design include using separate power supply for amplifier, or use external amplifier? | ||
| + | ** Expect only need amplifier for inner ring of insert | ||
| + | *** Expect 3x-6x gain at most | ||
| + | ** Plan is for URegina and UNCW to help out with effort | ||
| + | *** URegina can make boards or modify existing amplifiers, asked us to send 1-2 PMTs | ||
| + | * Working on CCAL refurbishment | ||
| + | ** Do not need 24x amplifier | ||
| + | ** Use no amplifier? | ||
| + | ** Middle ground: 3x amplifier with dip switch to disable | ||
| + | * Working on light monitoring system: Josh polishing new fibers | ||
| + | * Will get help from Tim W.'s group for module fabrication | ||
| + | * Igal working on 2γ mass distributions -> dark scalar search | ||
| + | ** π0 is huge background: limits search to m(2γ)<90 MeV? | ||
| + | ** Major sources of background: η→3π0 and π0π0 production | ||
| + | ** Thinking of backing off using reaction filter to get finer control in analysis | ||
| + | ** Current MC model for π0π0 background does not agree with data | ||
| + | *** MC distributions also not smooth, have strange peaking behavior where no peaks are expected | ||
| + | *** S.T. working on more realistic generator | ||
| + | *** Also could extract shape from real data | ||
| + | ** Thinking of switching to π+π- and π0π0 above 2 pion threshold | ||
Latest revision as of 09:16, 15 February 2021
Meeting time and location= 8:30 am EST (JLab time) Bluejeans only
Connection instructions
We are using BlueJeans Video/Audio conferencing. Our meeting ID number is 992533564. Click "Expand" for more details.
- Make sure you have created a BlueJeans account via your JLab CUE account using this link:
- http://jlab.bluejeans.com (You should only need to do this once)
- If connecting via Web Browser: click this link (no passcode is needed):
- If connecting via Phone: Dial one of the following numbers and then enter the meeting ID above and hit "#" or "##"
- Dial: 1 888 240 2560 (US or Canada only)
- or, List of International Numbers
- If connecting via Polycom unit:
- Dial 199.48.152.152 or bjn.vc
- Enter meeting ID above
Agenda
- SICCAS crystals
- Test of the active base
- COMCAL tests, TAC running, etc.
- Data analysis
- Simulations
Minutes
Attendees: Igal,Zisis,Phil,Sasha,Jared,Arsak,Tim B.,Tim W.,Liping,Jane,S.T.
- Attempts to communicate with our contact at SICCAS have failed
- Still expecting a batch from SICCAS: wait for 1-2 weeks while keep trying to contact the company
- Have money to spend on more crystals -- switch to CRYTUR?
- Sasha reported on linearity studies of amplifier used in redesigned PMT base
- During PrimeX run observed nonlinear behavior that was reduced when reduced gain and increased HV
- Bypassed the amplifier -> good performance
- Beam tests: used 24x amplifier: very nonlinear!
- Vlad P. worked on redesign: resistor changes to increase voltage on first dynode, addition of amplifier circuitry
- Sasha used HP pulse generator to mimic current source, studied amplifier with ~2.3x gain
- Gain drops off by ~10% below 0.5 V signal size, but stable at ~1-2% level above 0.5 V
- Important because central block gets most of energy in the shower (~80%)
- Linearity depends on HV, better linearity at higher divider currents
- Nominal HV=900 V
- Gain drops off by ~10% below 0.5 V signal size, but stable at ~1-2% level above 0.5 V
- Ideas to improve base design include using separate power supply for amplifier, or use external amplifier?
- Expect only need amplifier for inner ring of insert
- Expect 3x-6x gain at most
- Plan is for URegina and UNCW to help out with effort
- URegina can make boards or modify existing amplifiers, asked us to send 1-2 PMTs
- During PrimeX run observed nonlinear behavior that was reduced when reduced gain and increased HV
- Working on CCAL refurbishment
- Do not need 24x amplifier
- Use no amplifier?
- Middle ground: 3x amplifier with dip switch to disable
- Working on light monitoring system: Josh polishing new fibers
- Will get help from Tim W.'s group for module fabrication
- Igal working on 2γ mass distributions -> dark scalar search
- π0 is huge background: limits search to m(2γ)<90 MeV?
- Major sources of background: η→3π0 and π0π0 production
- Thinking of backing off using reaction filter to get finer control in analysis
- Current MC model for π0π0 background does not agree with data
- MC distributions also not smooth, have strange peaking behavior where no peaks are expected
- S.T. working on more realistic generator
- Also could extract shape from real data
- Thinking of switching to π+π- and π0π0 above 2 pion threshold
