Hall C SHMS Fringe Field Analysis Michael Moore Hall C Winter Meeting

Outline The Fringe Field Problem TOSCA model Results of simulations Conclusions Work that still needs to be done

SHMS Elements Q3 Q2 Q1 HB Target Dipole

How Close is too Close? HB Yoke Cryostat (coils inside) Beamline HMS Q1

The Model MSU’s 1006 Fe 1006 Fe 1010 HBQ1 Q2 Q3

Displacements Beam Dump Window 4” diameter x z x Target (9.21, ) *Not drawn to scale Beamline axis Displacement from center of beamdump window Beam Trajectory

“As Built” Fringe Fields HB Q1Q2 Q3 Integral: Maximum: Minimum: By Along Beampipe “As Built”, 11 GeV By (G) Z (cm)

Wedges Fringe Fields By (G) Z (cm) By Along Beampipe “Extra Fe”, 11 GeV HB Q1 Q2 Q3 Integral: Maximum: Minimum:

“As Built” and Wedges Displacements

60 cm Pipe HB Pipe

Two meter Pipe HB Pipe

Two meter Pipe with Q2 Collar

Conclusions Run pipe and Q2 collar at more angles and energies Optimize for smallest pipe length Add HMS (at least Q1) to the model Still to do As built, the SHMS is a >10 degree spectrometer With extra Iron on the yoke it is a > 9 degree spectrometer Iron pipe with wedges shows promise as a solution

Fitting the Beam in the Beamdump Window