Presentation on theme: "A Pressurized Gas Cerenkov Detector for PID in Hall A Robert J. Feuerbach Jefferson Lab Design and prospective fabrication in collaboration with: Argonne."— Presentation transcript:
A Pressurized Gas Cerenkov Detector for PID in Hall A Robert J. Feuerbach Jefferson Lab Design and prospective fabrication in collaboration with: Argonne National Laboratory, Rutgers University, and Jefferson Lab
Overview Design Goals: Separate and K for momenta above 2.3GeV/c. Continue to differentiate e/ Features: Operates at pressures up to 10 psig, using C 4 F 10 or CO 2 as the radiator. Expect average of 10 p.e. for a 2.3GeV/c pion with C 4 F 10 Experiments: Pentaquark (E05-009), Transversity SSA (E03-004) (backup), Flavor Asymmetry in SIDIS (PR04-114 cond. app.)
Design (cont) C 4 F 10 chosen for its high index-of-refraction Try to re-use as much of the current detector as possible to control costs and unknowns – Re-use optics from present cerenkov. – Can the present box be re-used? What modifications are necessary? Finite element analysis by Ravi Anumagalla
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,
Model 4: Plot shows surfaces where stresses are in the range of 0-23 ksi
Design (cont) Can the present box be re-used? What modifications are necessary? Finite element analysis by Ravi Anumagalla – Weight goes from 750lbs to ~2200lbs. – Higher risk factor Another idea: window-less titanium cylinder with interior supports (concept 1) Cylindrical chamber w/ windows (concept 2)
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%).
Conclusion Pressurized Cerenkov design continuing. Should provide excellent pi/K separation for momenta greater than 2.3 GeV/c. Rejection factor of ~370 for a threshold of 3p.e.'s. Modified design (2) is estimated at $49k (including contingency).
R ich /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/c4 separation at ~ 3.0 GeV/c Mauro Iodice – R ICH2004 - Playa del Carmen, Mexico - Nov.30 Dec. 5, 2004
R ich /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 – R ICH2004 - Playa del Carmen, Mexico - Nov.30 Dec. 5, 2004 M onte C arlo Simulations