Difference between revisions of "Dec 8, 2008 Calorimetry"
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# BCAL | # BCAL | ||
## [[Fiber Test with SiPM | Testing of fibers with SiPM readout and Sr90 source]] (Beni)[http://www.jlab.org/~zihlmann/fibertest/ScintillationFiberTestsatJlab.ppt Talk] | ## [[Fiber Test with SiPM | Testing of fibers with SiPM readout and Sr90 source]] (Beni)[http://www.jlab.org/~zihlmann/fibertest/ScintillationFiberTestsatJlab.ppt Talk] | ||
− | ## [ | + | ## [https://halldweb.jlab.org/doc-private/DocDB/ShowDocument?docid=1130 Lead Specification] (Elton) |
## Magnetic Field Update (JLab) | ## Magnetic Field Update (JLab) | ||
## Other updates | ## Other updates | ||
Line 35: | Line 35: | ||
=Minutes= | =Minutes= | ||
− | Attending: Athens: George | + | Attending: Athens: George Voulgaris, Christina; JLab: Tim, Fernando, Beni, Elke, Elton; FSU: Alex; UofR: Blake, Zisis, George, Andrei; IU: Matt (please add others if present) |
# Announcements | # Announcements | ||
#* Elton will attend Sendai08 to present some Hall B data and will take advantage of trip to visit Kuraray. | #* Elton will attend Sendai08 to present some Hall B data and will take advantage of trip to visit Kuraray. | ||
# Calibration | # Calibration | ||
− | #* | + | #* No updates on the calibration table requirements. Alex indicated that FSU will review the table and give feedback as testing on TOF detectors proceeds. |
+ | #* George V. reviewed the two posted presentations, one on pmt and APD linearity and the second on LED thresholds. | ||
+ | #* First, radiated noise from laser reduced using a Faraday cage. Remaining background levels in APD spectra (50 mV) reduced to 2 mV using various stages of shielding. | ||
+ | #* Linearity of APD established by comparing to LED. Comparing pmt to LED, determined range of "overlinearity". After correction for this non-linearity, the measured response ratio between pmt and APD is 3.3/3.2. | ||
+ | #* Conclusion: APD is useful device for calibration. In comparisons with PMT, Elke cautioned that one is comparing different active areas as well as different gains. | ||
+ | #* Christina: Main goals at present ar to compare linearity and time stability. | ||
+ | #* Zisis: Inquired about future measurements with SiPMs? Yes, that is the plan. Also, the fine mesh PMT will be studied. | ||
+ | #* For LEDs, additional studies are required on temperature and time stability | ||
+ | #* Elke: Should review existing literature and other detectors as basis for planning design. Christina, said that indeed a review of literature has been conducted and most systems either use lasers with optical benches (expensive), or moving toward LEDs, which they are presently investigating. | ||
+ | #* Christina: most of the laser tests have been completed, they are now concentrating on LED tests. | ||
+ | #* Elton asked what were the driving inputs that are required to design the calibration system. George V.: dynamic range is one of the major factors. Fernando: His experience is that LEDs vary considerably in output (even from the same batches) and recommended testing a larger sample to investigate variation in light output. | ||
# FCAL Update | # FCAL Update | ||
+ | #* No update | ||
# BCAL | # BCAL | ||
## [[Fiber Test with SiPM | Testing of fibers with SiPM readout and Sr90 source]] (Beni)[http://www.jlab.org/~zihlmann/fibertest/ScintillationFiberTestsatJlab.ppt Talk] | ## [[Fiber Test with SiPM | Testing of fibers with SiPM readout and Sr90 source]] (Beni)[http://www.jlab.org/~zihlmann/fibertest/ScintillationFiberTestsatJlab.ppt Talk] | ||
− | ## [ | + | ##* Summary of light output at three differenct distances using pmts and SiPMs for Bicron and Kuraray fibers. All summarized on wiki. Beni will consolidate into a GlueX-doc note and post on the portal. |
+ | ##* Andrei inquired about the subtraction of non-source triggers in the SiPM measurement. Under question was the ratio of cosmic-ray triggers vs. pmt dark rate. Beni indicated that the correction was only 20%, so it could not affect the conclusions very much. However, it will be quantified further. | ||
+ | ##* Zisis asked about the differences between this measurement and the spectophotometer measurements. This is likely due to the assumed PDE function for the SiPMs (about 13%) used in the interpretation of the spectrophotometer measurements. | ||
+ | ## [https://halldweb.jlab.org/doc-private/DocDB/ShowDocument?docid=1130 Lead Specification] (Elton) | ||
+ | ##* There has been an iteration on the Pb spec with George and Zisis. A close to final spec has been posted on the portal. Tim will get feedback from vendors about the difficulty in supplying specific lead sheets sizes. | ||
+ | # Nex time: | ||
## Magnetic Field Update (JLab) | ## Magnetic Field Update (JLab) | ||
− | ## | + | ## [[Resolution studies]] |
− | + | ||
− | + |
Latest revision as of 17:08, 24 February 2017
Time: 11:15 ET.
- Phone:
- +1-800-377-8846 : US
- +1-888-276-7715 : Canada
- +1-302-709-8424 : International
- then enter participant code: 39527048# (remember the "#")
Contents
Items for followup from Nov 24 meeting
- Updates on Calibration Specification Table.
- Resolution studies (Blake)
- Develop criteria for evaluating resolution studies
- Study impact of inactive material at the end of Bcal on acceptance.
- Check what configuration (thresholds, step sizes, stack? parameters for secondaries, etc) is being used for the Hall D simulations (Regina)
- Report on the Bfield components in the region of the Bcal reaout (JLab for next meeting).
Documents to Review
- Calibration/monitoring update Athens (old version): Media:APD_vs_tube_linearity.ppt
- Calibration/monitoring update Athens (updated): Media:APD_vs_tube_linearity2.ppt
- Calibration/monitoring update Athens: Media:Threshold.ppt
Tentative Agenda (Emphasis is Calibration)
- Announcements
- Calibration
- Progress on filling in the Calibration Specification Table.
- FCAL Update
- BCAL
- Testing of fibers with SiPM readout and Sr90 source (Beni)Talk
- Lead Specification (Elton)
- Magnetic Field Update (JLab)
- Other updates
- if time: Resolution studies
- Any other business
Minutes
Attending: Athens: George Voulgaris, Christina; JLab: Tim, Fernando, Beni, Elke, Elton; FSU: Alex; UofR: Blake, Zisis, George, Andrei; IU: Matt (please add others if present)
- Announcements
- Elton will attend Sendai08 to present some Hall B data and will take advantage of trip to visit Kuraray.
- Calibration
- No updates on the calibration table requirements. Alex indicated that FSU will review the table and give feedback as testing on TOF detectors proceeds.
- George V. reviewed the two posted presentations, one on pmt and APD linearity and the second on LED thresholds.
- First, radiated noise from laser reduced using a Faraday cage. Remaining background levels in APD spectra (50 mV) reduced to 2 mV using various stages of shielding.
- Linearity of APD established by comparing to LED. Comparing pmt to LED, determined range of "overlinearity". After correction for this non-linearity, the measured response ratio between pmt and APD is 3.3/3.2.
- Conclusion: APD is useful device for calibration. In comparisons with PMT, Elke cautioned that one is comparing different active areas as well as different gains.
- Christina: Main goals at present ar to compare linearity and time stability.
- Zisis: Inquired about future measurements with SiPMs? Yes, that is the plan. Also, the fine mesh PMT will be studied.
- For LEDs, additional studies are required on temperature and time stability
- Elke: Should review existing literature and other detectors as basis for planning design. Christina, said that indeed a review of literature has been conducted and most systems either use lasers with optical benches (expensive), or moving toward LEDs, which they are presently investigating.
- Christina: most of the laser tests have been completed, they are now concentrating on LED tests.
- Elton asked what were the driving inputs that are required to design the calibration system. George V.: dynamic range is one of the major factors. Fernando: His experience is that LEDs vary considerably in output (even from the same batches) and recommended testing a larger sample to investigate variation in light output.
- FCAL Update
- No update
- BCAL
- Testing of fibers with SiPM readout and Sr90 source (Beni)Talk
- Summary of light output at three differenct distances using pmts and SiPMs for Bicron and Kuraray fibers. All summarized on wiki. Beni will consolidate into a GlueX-doc note and post on the portal.
- Andrei inquired about the subtraction of non-source triggers in the SiPM measurement. Under question was the ratio of cosmic-ray triggers vs. pmt dark rate. Beni indicated that the correction was only 20%, so it could not affect the conclusions very much. However, it will be quantified further.
- Zisis asked about the differences between this measurement and the spectophotometer measurements. This is likely due to the assumed PDE function for the SiPMs (about 13%) used in the interpretation of the spectrophotometer measurements.
- Lead Specification (Elton)
- There has been an iteration on the Pb spec with George and Zisis. A close to final spec has been posted on the portal. Tim will get feedback from vendors about the difficulty in supplying specific lead sheets sizes.
- Testing of fibers with SiPM readout and Sr90 source (Beni)Talk
- Nex time:
- Magnetic Field Update (JLab)
- Resolution studies