SHMS MC Working Group

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SHMS Characteristics

Drawings of magnets

Study of the SHMS resolution

  • Study of the SHMS resolution.


Moved Snake section here.


[Dave G. notes on 2009 shms studies]

[Comparison of 1st order matrix elements from Dave G. COSY fits and John LeRose tech note]

Aperture study

  • Aperture 1, compared 20cm target at 20 deg with: (top panel), the blue points show the distribution when all apertures are included, while the red points are with no dipole apertures and no HB mechanical apertures. (Bottom panel), blue is same as above and the red show distributions with no dipole apertures, no HB apertures and no Q1,Q2,and Q3 Mech apertures, ie only apertures included are the Q1, Q2, Q3 magnetic centers.

  • Apertures 3, Here in the bottom panel, only the HB apertures and Q1,Q2, Q3 mechanical apertures are removed. This is the minimal set of apertures which have to be turned off to get the distributions similar to the pre 2009 distributions. It should also be noted that this is the set of apertures is what existed in the pre 2006 mc_shms.f

  • Acceptance for the no aperture (other than Q1,2, and 3 magnetic center apertures) is 4.6 msr

Collimator study

  • Run COSY based MC with target of length +/-10cm at 20deg. Use a 26cm offset in the dipole with 23cm opening in HB.
  • Plot1, Plot2of the vertical position versus the horizontal position at Q1 entrance. In the bottom right plot the red are events which are accepted up to the dipole entrance. The blue are those events which fail in the dipole. Plot1 is for D/M=0.08, Plot2 is for D/M=0.12, cut on delta -10<delta<22
  • Plot1, Plot2 of solid acceptance versus delta for cuts in the vertical acceptance at the entrance of Q1 for events with vertical position at Q1 less than 7 (magenta) , 9 (blue), 11 (green), 13cm (red) and no cut (black). The no cut acceptance was assumed to be 4 msr. Plot1 for D/M=0.08 and Plot2 for D/M=0.12, no delta cut is applied
  • Plot1, Plot2 of vertical position vs horizontal position at Q1 entrance for events with vertical position at Q1 less than 7 (green) , 11 (magenta), 13cm (blue) and no cut (red). Plot1 is for D/M=0.08 and Plot2 is for D/M=0.12, cut on delta -10<delta<22


Moved to Collimators and Slits for SHMS

Detector Positions

Moved to Detector_Locations_in_SHMS location