Difference between revisions of "GlueX TOF Meeting, December 20, 2012"

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(Wrapping Material)
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==Slides==
 
==Slides==
  
Talks can be deposited in the directory <code>/group/halld/www/halldweb1/html/talks/2012-4Q</code> on the JLab CUE. This directory is accessible from the web at https://halldweb1.jlab.org/talks/2012-4Q/ .
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Talks can be deposited in the directory <code>/group/halld/www/halldweb/html/talks/2012-4Q</code> on the JLab CUE. This directory is accessible from the web at https://halldweb.jlab.org/talks/2012-4Q/ .
  
 
=Minutes=
 
=Minutes=
  
 
Present:
 
Present:
'''FSU''': Sasha Ostrovidov
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* '''FSU''': Sasha Ostrovidov
'''JLab''': Chuck Hutton, Mark Ito (chair)
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* '''JLab''': Chuck Hutton, Mark Ito (chair)
  
 
==PMT Testing==
 
==PMT Testing==
Line 49: Line 49:
  
 
==Scintillator Bars==
 
==Scintillator Bars==
received 6 scintillator bars
 
2 regular 2 narrow and 2 short
 
  
some bars are out of tolerance by 1 or two mils above 5 mil tolerance
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The six scintillator bars for the mini-TOF have been received at FSU: 2 regular, 2 half-width, and 2 half-length bars. Eljen's [http://hadron.physics.fsu.edu/TOF/doc/Eljen_Dimension_Report-1stArticle.pdf measurements of the dimensions] show that some are out of tolerance by one or two mils less than the 5 mil limit. Eljen also shipped [http://hadron.physics.fsu.edu/TOF/doc/Eljen_Scint_Test_Report-1stArticle.pdf performance data] on the scintillator. (The interpretation of the "light output" spectrum a mystery currently.)
  
working on 3rd batch
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Although they have not been shipped yet, Eljen reports that in the next batch of 76 regular bars, 12 of them are 1/8 inch short. A decision on whether to accept these has not been made. Chuck will look at the mechanical implications.
produced 76 normal bars
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1/8" inch short , 12 of them
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not accepted yet
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sasha setting up for scintillator measurements
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Sasha is setting up for measurements on the scintillator received. They will be put into the dark box, with a spring loaded mechanism to hold the PMTs, and tested with a strontium source at various locations along the bar. Both ADC and TDC data will be taken to get attenuation length and speed of light.
put into dark box
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spring loaded mechanism to hold pmts
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Sr source at various points,
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get adc and tdc
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light output spectrum a mystery
+
  
 
==Mini-TOF Assembly==
 
==Mini-TOF Assembly==
  
all parts made for mini-tof
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All parts have been made for the support structure. Sasha plans to finish testing the scintillator this week so that gluing of the light guides can start in January. The schedule for starting assembly of the complete schedule will also depend on when the ESR material arrives.
mid january start gluing,
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finish tresting this week
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start early january gluing
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ESR  
+
  
 
==Design Work==
 
==Design Work==
chuck is putiing mini tof ideas into final design
 
  
Chuck thinks eyes-on would be a good idea.
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Chuck is putting the mini-TOF ideas as they currently stand into the design of the complete TOF.

Latest revision as of 23:18, 31 March 2015

GlueX TOF Meeting
Thursday, December 20, 2012
10:00 am EDT
JLab: CEBAF Center, F326

Agenda

  1. Announcements
  2. Review of last TOF bi-weekly meeting
  3. Mechanical design
    1. MiniTOF
    2. TOF Gluing Fixture
    3. TOF Module Wrapper
  4. PMT testing
  5. Contract status
  6. Calibration and Alignment
  7. Technical Design Report contribution

Communication

Videoconference

  1. ESNet: 8542553
  2. EVO: EVO site

Slides

Talks can be deposited in the directory /group/halld/www/halldweb/html/talks/2012-4Q on the JLab CUE. This directory is accessible from the web at https://halldweb.jlab.org/talks/2012-4Q/ .

Minutes

Present:

  • FSU: Sasha Ostrovidov
  • JLab: Chuck Hutton, Mark Ito (chair)

PMT Testing

  • There are four undergraduates working on testing PMTs now.
  • 130 PMTs have been received (batches 1, 2, and 3).
    • All of them have been tested with an LED, with gain measured via a visible single-photoelectron peak. All tubes passed.
    • 70% of them have been tested with an americium source to look at photocathode efficiency
    • 10% of them have been tested with a cesium source on a sodium iodide crystal.

Wrapping Material

Paul Eugenio has succeeded in negotiating purchase of rolls of ESR material from 3M, rather than in the 2×3 foot sheets that were originally offered. The rolls are 8 inches wide and about 1000 feet long. Also, there will be no adhesive layer attached to the material; the total thickness will be 1 mil. The purchase order has already been sent to 3M. Shipment is expected sometime in January.

Scintillator Bars

The six scintillator bars for the mini-TOF have been received at FSU: 2 regular, 2 half-width, and 2 half-length bars. Eljen's measurements of the dimensions show that some are out of tolerance by one or two mils less than the 5 mil limit. Eljen also shipped performance data on the scintillator. (The interpretation of the "light output" spectrum a mystery currently.)

Although they have not been shipped yet, Eljen reports that in the next batch of 76 regular bars, 12 of them are 1/8 inch short. A decision on whether to accept these has not been made. Chuck will look at the mechanical implications.

Sasha is setting up for measurements on the scintillator received. They will be put into the dark box, with a spring loaded mechanism to hold the PMTs, and tested with a strontium source at various locations along the bar. Both ADC and TDC data will be taken to get attenuation length and speed of light.

Mini-TOF Assembly

All parts have been made for the support structure. Sasha plans to finish testing the scintillator this week so that gluing of the light guides can start in January. The schedule for starting assembly of the complete schedule will also depend on when the ESR material arrives.

Design Work

Chuck is putting the mini-TOF ideas as they currently stand into the design of the complete TOF.