Hall A Pressurized Gas Cerenkov

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Hall A Pressurized Gas Cerenkov

• Design Goals
• Separate ? and K for pgt2.3GeV/c.
• Continue to differentiate e/?
• Features
• Operates at pressures up to 10 psig, using C4F10
  or CO2 as the radiator.
• Expect average of 10 p.e. for a 2.3GeV/c pion
  with C4F10
• ? rejection factor of 400 (3 p.e. cutoff)

Experiments Pentaquark (E05-009), Transversity
SSA (E03-004), Flavor Asymmetry in SIDIS
(PR04-114 cond. app.) Design and fabrication in
collaboration withArgonne National Laboratory,
Rutgers University, and Jefferson Lab
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Design performance
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Design (cont)

• Control cost and effort by re-using optics from
  present cerenkov.
• Can the present box be re-used? What
  modifications are necessary? Finite element
  analysis by Ravi Anumagalla

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Design performance
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Model 4 No top and Bottom faces, includes a C
Channel on one face Max Stress 263 ksi Max
Deflection 1.59 inches Boundary Conditions
Pressure on all faces (14.7 psi), Fixed at the
bottom and top surface,
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Model 4 Plot shows surfaces where stresses are
in the range of 0-23 ksi
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Design (cont)

• Control cost and effort by re-using optics from
  present cerenkov.
• Can the present box be re-used? What
  modifications are necessary? Finite element
  analysis by Ravi Anumagalla
• Weight goes from 750lbs to 2200lbs.
• Another idea by Bogdan titanium cylinder with
  interior supports (being priced now)

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Bogdans concept
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Common features

• PMT sealed against interior for servicing while
  the chamber is pressurized.
• Simple stationary gas system since it will be
  filled from the Hall B gas system.
• Size is compatible with current short cerenkov.
• Low-number of knock-on electrons for 0.4mm Ti
  window (lt2).

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0.36
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Conclusion

• Pressurized Cerenkov design continuing.
• Should provide excellent pi/K separation for
  momenta greater than 2.3 GeV/c
• Need to finalize the design (after cost estimates
  are made)

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Rich p/K separation for p gt 2.5 GeV/c
Radiator C5F12 n1.24 sCh 5mr
Radiator C6F14 n1.29 sCh 5mr
4 s separation at 2.5 GeV/c
4 s separation at 3.0 GeV/c
Mauro Iodice RICH2004 - Playa del Carmen,
Mexico - Nov.30 Dec. 5, 2004
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Rich p/K separation with C5F12 (n1.24) radiator
(14 cm proximity gap)
MonteCarlo Simulations
gt20 s separation at 2 GeV/c
4 s separation at 3.0 GeV/c
Mauro Iodice RICH2004 - Playa del Carmen,
Mexico - Nov.30 Dec. 5, 2004