1. Super BigBite concepts Bogdan Wojtsekhowski, JLab
Physics requirements
Some experiments
Layout for the GEP-15
Proposed spectrometer
Detector configuration
Expected parameters
Stages of implementation

2. Physics requirements Generic experiments to consider: Requirements:
Inclusive (e,e’) - pol DIS
Exclusive (e,e’N) - GEP/GMP
Semi-inclusive (e,e’h) - SIDIS
Requirements:
Solid angle - > 20 msr
Scattering angle deg.
Momentum range GeV/c

3. 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

4. GEP-15 layout

5. 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

6. 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!

7. Small angle concept

8. Layout of SuperBigBite
2-nd arm
RICH Preshower Shower

9. Parameters mrad msr
Momentum acceptance at full field - 2 GeV/c and higher
Momentum resolution ~ 0.5% for 8 GeV/c
Solid angle at 14 degree is 55 msr (72” from pivot to yoke)
Solid angle has aspect ratio 1:2.5
Angle resolution of 0.3 mrad
Vertex resolution of 1 mm
Target length 40 cm
Simple optics, flat acceptance - perfect for terms like sin2
mrad 5 10 15 20
msr 13 38 58 85

10. The 48D48 magnet at BNL
100 tons, 18.5” x 48” x 48” field volume

11. GEM base tracker
Rate capability ~ 10 kHz/mm2

12. Best PID: fast RICH -like in HERMES
Sensitive area ~ 60x200 cm2 viewed with 1934 PMTs

13. 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/