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/