Polarimeter Documentation

C-GEN Polarimeter Design / Documentation

• (18 Sept 2014) JT2go 3D model (based on working model in JLab CAD system; Contact: Paulo Medeiros)
  • JT2go viewer (Windows)
  • Hall layout w/ mock-up of Magnets and "Plan B" detector using 160cm bars (JT file)
  • Images extracted from the above JT file:

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  File:Top-with scale-18Sep2014.pdf

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  File:Top-with scale midplane cut-18Sep2014.pdf

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  File:Side-isometric-18Sep2014.pdf

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  File:Side isometric-midplane cut-18Sep2014.pdf

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  File:Side-isometric no mag1-18Sep2014.pdf

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  File:Side isometric no mag2-18Sep2014.pdf

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  File:Top isometric midplane cut-18Sep2014.pdf

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  File:Top zoomed-out-18Sep2014.pdf

Possible scintillator hardware

The "Plan B" design requires:

• Total: 136x 10 cm x 10 cm "thick" bars

108   10 cm  x 10 cm x 160 cm   E counters (top + bottom)
 28   10 cm  x 10 cm x 160 cm   analyzer bars

• Total: 80x 1 cm x 10 cm "thin" bars

 52    1 cm  x 10 cm x 160 cm   dE  (top + bottom)
 28    1 cm  x 10 cm x 160 cm   analyzer vetos

• All bars are double-ended readout.

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Existing Scintillator Bars

BLAST bars (some from PSI LADS detector)

 Ohio walls: 16x      10 cm x 22.5 cm    x 400 cm  <-- these are the ones we are principally interested in
 LADS15:     28x      15 cm x 14.5 cm(*) x 160 cm
 LADS20:     28x      20 cm x  9.8 cm(*) x 160 cm
 (*) bars are trapezoidal shaped; this is mid-point thickness

• Availability: Yes (we have a promise that the Ohio walls are ours; they can remain at MIT for the time being. A trip to take a look at them and confirm their condition would be wise.)
• Location: BATES
• Contact: Michael Kohl / Bob Redwine (MIT)
• References: NIM A 603 (2009) 247–262 (BLAST detector), NIM A 373 ( 1996) 374-38 (PSI LADS reference)
• Notes:
  • Bars would need to be cut and polished (Kent State?).
  • New PMTs are likely.
  • Primarily interested in the Ohio walls.
    • The LADS bars are trapezoidal; they can be stacked into planes by alternating the 'wedge' direction. Not even sure if they are available as well(?)

"BigBite" HAND

 32x   10 cm x 10  cm  x  100 cm
 32x   10 cm x 12.5cm  x  100 cm
 12x   10 cm x 15  cm  x  100 cm
 12x   15 cm x 25  cm  x  100 cm
 32x    2 cm x 11  cm  x  100 cm

• Availability: Yes
• Location: JLab ESB
• Contact: Doug Higinbotham
• Reference: Wermus Tech Note
• Notes:
  • These are available now
  • Will likely need to replace most of the (3") PMTs

GEn E02-013 BigHAND neutron array

UVa:      100x     10 cm x 10 cm x 160 cm
Glasgow:   24x     10 cm x 20 cm x 180 cm
CMU:      120x      5 cm x 15 cm x 180 cm

• Availability: ??? (there are plans to use the BigHAND array in Hall A)
• Location: Bldg 64 (tent at NE corner of Accel area)
• Contacts: Mixed: UVa (Donal Day), CMU (G. Franklin?), Glasgow (J. Annand); Bogdan, Albert (JLab)
• Reference: BigHAND Geometry], General Documentation]
• Notes:
  • These are still stored in the BigHAND cartridges in Bldg 64
  • PMT status TBD
  • At our 2013 collaboration meeting Donal mentioned the UVa bars are still available and are still under UVa ownership.

Existing Material at Kent State

8x  10 cm x 51 cm x 100 cm   (actual dimensions: 4" x 20" x 40")
3x  10 cm x 25 cm x 100 cm   (actual dimensions: 4" x 10" x 40")

• Availability: Yes
• Location: Kent State
• Contacts: Bryon Anderson
• Reference:
• Notes:
  • Needs cutting and polishing
  • PMTs needed

Existing bars within Collaboration

SUNO    (Mostafa Elaasar):   ??x   1 cm x 10 cm x 100 cm
La Tech (Steve Wells):       ??x  10 cm x 10 cm x 100 cm

• Availability: Yes
• Notes:
  • Purchased as test bars with an eye to incorporation into full polarimeter
  • PMTs are included

Miscellaneous

• Simulation software may be found here: Software
• Calibration of a neutron polarimeter in the 0.2–1.1 GeV region [NIMA557 (2006) 585-593]: File:JLAB-PHY-06-461.pdf