Super BigBite concepts Bogdan Wojtsekhowski, JLab

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Super BigBite concepts Bogdan Wojtsekhowski, JLab

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

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Physics requirements

• Generic experiments to consider
• Inclusive (e,e) - pol DIS
• Exclusive (e,eN) - GEP/GMP
• Semi-inclusive (e,eh) - SIDIS

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

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Some of Experiments

• GMN with 6 GeV beam (Q2 up to 8 GeV2)
• Many experiments for 11 GeV beam
• GEP - unique kinem. correlation -gt L 1039
• A1n/d2n A1p/dp
• Transversity (e,e????) and (e,eK/-)
• FFs with polarized target - GEN, GEP

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GEP-15 layout
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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

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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 gt 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!

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Small angle concept
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Layout of SuperBigBite
2-nd arm
RICH Preshower Shower
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Parameters
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
12.5 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
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The 48D48 magnet at BNL
100 tons, 18.5 x 48 x 48 field volume
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GEM base tracker
Rate capability 10 kHz/mm2
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Best PID fast RICH -like in HERMES
Sensitive area 60x200 cm2 viewed with 1934 PMTs
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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 BNLs)
• Construction of the tracking detectors - BIG NEW!
• I - 10x10 cm prototype, II- 40x140 cm
  prototype
• Francos collaboration INFNGlasgowUVAFIU
  JLab
• Reconstruction of the hadron calorimeter -
  WMDubna
• More proposals are under development for 12 GeV
  PACs
• Possible second arm magnet for the J/?