05/04/2007 Transversity Collaboration Meeting 1

HRS Aerogel Detectors

Lingyan ZhuUniversity of Illinois at Urbana-Champaign

forTransversity Collaboration Meeting

May 4th, 2007

05/04/2007 Transversity Collaboration Meeting 2

HRS PID Detectors

Kinematics: P=2.4 GeV

Singles Rates:

pi- 1.01k; K- 0.05k; e- 0.17k; pi+ 1.69k; K+ 0.34k; p 0.96k

Scintillators: some pi/K/p separation with TOF (pi/K--1.6ns; K/p--4.4ns;FWHM with S2M can be 0.66 ns. )

Pion Rejector & Gas Cherenkov: pi(K)/e separation

RICH *1.3: better than 1:1000 pi/K rejection on 80% of the momentum acceptane; lower 15% with ~1:100 rejection.

Aerogel Detectors A1(n=1.015) and A2(n=1.055): additional pi/K/p separation especially at the low momentum.

05/04/2007 Transversity Collaboration Meeting 3

Upgraded RICH Performance

Evaristo Cisbani, Readiness Review

05/04/2007 Transversity Collaboration Meeting 4

The Historical A1/A2 performance

Stefeno Marrone et al, draft paper on A1/A2

2000 original

2005 restored

2004 degraded

P=2 GeV

05/04/2007 Transversity Collaboration Meeting 5

Current Status of A1/A2 (Jan 2007)

Pete Markowitz: http://www.jlab.org/~markowit/Aerogel.html

A1 A2

yellowsurface

falling paper

05/04/2007 Transversity Collaboration Meeting 6

Near Plan of FIU/JLab

Pete Markowitz, Bogdan Wojtsekhowski

Refurnishing of the PMT box of A2 is under way.

To start cosmic test on A2 in about a month and then decide whether to refurnish its aerogel box.

The plan for A1 will depend on result with A2.

May lower the index of A2 from 1.055 to 1.030.

Manpower needed: ~2 man-month per counter.

05/04/2007 Transversity Collaboration Meeting 7

pi/K Identification at Different Index

P=2.4GeV

pi

K

p