Super BigBite concepts Bogdan Wojtsekhowski, JLab

Physics requirements Some experiments Layout for the GEP-15 Proposed spectrometer Detector configuration Expected parameters Stages of implementation

Physics requirements

Requirements:• Solid angle - > 20 msr• Scattering angle - 5-30 deg.• Momentum range - 1-8 GeV/c

Generic experiments to consider:• Inclusive (e,e’) - pol DIS• Exclusive (e,e’N) - GEP/GMP• Semi-inclusive (e,e’h) - SIDIS

Some of Experiments

• GMN with 6 GeV beam (Q2 up to 8 GeV2)

Many experiments for 11 GeV beam:

• GEP - unique kinem. correlation -> L ~ 1039 • A1n/d2n; A1p/dp; • Transversity (e,e’) and (e,e’K+/-)• FFs with polarized target - GEN, GEP

GEP-15 layout

Design considerations

• Vertical bending• Detector should be behind magnetic field• Compact beam spot on the target• Simple dipole is the best for large momentum bite• Field integral and bend angle vs detector

resolution• Progress in tracking detector technology

Proposed Spectrometer

• Magnet of 100 tons with aperture 46 cm x 122 cm full 3 Tesla-meter field integral

• Detector package:- GEM trackers resolution: 0.07 mm - Calorimeter based trigger > 1 GeV - Lead-glass PID for electron - Fast RICH from HERMES for ,K

How to put a wide magnet at 10o angle near the target? Iron yoke is cut off to allow for the beam pipe!

Small angle concept

Layout of SuperBigBite

RICH Preshower Shower2-nd arm

Parameters

Momentum acceptance at full field - 2 GeV/c and higherMomentum resolution ~ 0.5% for 8 GeV/cSolid angle at 14 degree is 55 msr (72” from pivot to yoke)Solid angle has aspect ratio 1:2.5Angle resolution of 0.3 mradVertex resolution of 1 mmTarget length 40 cmSimple optics, flat acceptance - perfect for terms like sin2

mrad 5 10 15 20

msr 13 38 58 85

The 48D48 magnet at BNL

100 tons, 18.5” x 48” x 48” field volume

GEM base tracker

Rate capability ~ 10 kHz/mm2

Best PID: fast RICH -like in HERMESSensitive area ~ 60x200 cm2 viewed with 1934 PMTs

Plans

Development will be driven/funded by the GEP-15 collaboration Components reused are a magnet and both calorimeters

• Proposal GEP/GMP (GEP-15) is submitted to the PAC32• Proposal GMN/GMP is under preparation to the next PAC• GMN with the magnet - before 2011 at 50% field ( 1/4 power )• Support stand and full power for the magnet (refurbished BNL’s)• Construction of the tracking detectors - BIG NEW! I - 10x10 cm prototype, II- 40x140 cm prototype Franco’s collaboration: INFN+Glasgow+UVA+FIU+JLab• Reconstruction of the hadron calorimeter - W&M+Dubna• More proposals are under development for 12 GeV PACs • Possible second arm magnet for the J/