Schematic of the SHMS in Hall C at 12 GeV
SHMS design parameters
Central Momentum:2 to 11 GeV/c
Momentum Acceptance:
-10% < δ < +22%
Momentum Resolution:
0.03%-0.08%
Scattering Angle:
5.5 to 40°
Vertex Length (90deg):
30cm
Horizontal acceptance:
+- 24mrad
Vertical acceptance:
+- 55 mrad
Solid angle acceptance:
5.0 msr
Horizontal resolution (YPtar):
0.5-1.2 mrad
Vertical resolution (XPtar):
0.3-1.1 mrad
Vertex length res (Ytar):
0.1-0.3 cm
Hall C 12GeV Upgrade
NEWS ABOUT SHMS DESIGN
Momentum acceptance slightly tightened to -10% to +22% to avoid regions of rapidly varying acceptance, solid angle increased to about 5 msr, and the lab scattering angle increased to 40°. The acceptance can accomodate all current 12 GeV Hall C experiments (with effective target lengths up to 26 cm). The scattering chamber can accomodate up to 50-cm long targets.
Note that for simulations for upcoming 12 GeV PACs, one should assume the "standard" 10 cm, 20 cm, and 30 cm cryotargets will be available. Please note that the total beam current available for Hall C and Hall A together will be 85 micro-amps (11 GeV equivalent).
CURRENT SHMS STUDIES AND R&D
To date, the 12 GeV PAC has met three times and fully approved 7 experiments for Hall C. Experiment proposals submitted to PAC30 (2006), the proposals submitted to PAC32 (2007) , and the proposals submitted to PAC34 (2009)
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Hall C 12 GeV Document Database (including official figures, password required)
The document database contains all documentation associated with the Hall C 12 GeV upgrade including detector and SHMS R&D work. The Hall C Public Document Database lists public interest Hall C and 12 GeV documents.
The beam sizes at different z-locations in the SHMS detector hut for the design of the SHMS detectors. The beam sizes are taken into account in the construction of the latter.
The slit system will consist of a permanent, remotely controlled collimator/sieve slit box in front of Q1, and a special calibration sieve slit that can be temporarily inserted by hand before the horizontal bender.
Information about the prototype test performed in 2006 and the results of the simulation. The test results show that radiative heating is less than 1W, and so with in the design tolerance.
Report on the contribution of backgrounds at 12 GeV in Hall C and the SHMS shield house design. The shield house will consist of separate detector and electronics huts, which will be made from concrete, lead, and boron in order to protect the experimental equipment from different types of background radiation.
SHMS USERS GROUP
The SHMS-HMS Users' Group has recently been formed and will coordinate JLab and user involvement in the construction, comissioning, and understanding of the SHMS. Bylaws, email list, and a brief overview are now available.
OTHER 12 GEV LINKS
- Information about the MC
- Drawing of the Layout (M. Fowler)
- Information about the upgrade
- Presentation from the Hall C 12 GeV meeting
- Presentation from the Hall C 12 GeV meeting