Hall A Pressurized Gas Cerenkov Design Goals: Separate and K for p>2.3GeV/c. Continue to differentiate e/ Features: Operates at pressures up.

Hall A Pressurized Gas Cerenkov

Design Goals: Separate and K for p>2.3GeV/c. Continue to differentiate e/

Features: Operates at pressures up to 10

psig, using C4F

10 or CO

2 as the

radiator. Expect average of 10 p.e. for a

2.3GeV/c pion with C4F

10

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 with:Argonne National Laboratory, Rutgers University,

and Jefferson Lab

Design performance

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

Design performance

Model 4: No top and Bottom faces, includes a “C” Channel on one face

Max Stress : 263 ksiMax Deflection : 1.59 inches

Boundary Conditions: Pressure on all faces (14.7 psi), Fixed at the bottom and top surface,

Model 4: Plot shows surfaces where stresses are in the range of 0-23 ksi

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)

Bogdan’s concept

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 (<2%).

0.36%

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)

Rich /K separation for p > 2.5 GeV/c

Radiator C6F14 n=1.29 Ch ~ 5mr

Radiator C5F12 n=1.24 Ch ~ 5mr

4 separation at ~ 2.5 GeV/c 4 separation at ~ 3.0 GeV/c

Mauro Iodice – RICH2004 - Playa del Carmen, Mexico - Nov.30 Dec. 5, 2004

Rich /K separation with C5F12 (n=1.24) radiator (14 cm proximity gap)

>20 separation at ~ 2 GeV/c ~ 4 separation at 3.0 GeV/c

Mauro Iodice – RICH2004 - Playa del Carmen, Mexico - Nov.30 Dec. 5, 2004

MonteCarlo Simulations