SHMS Optics Working Group

Weekly Meetings

Meetings will be held on Thursdays 11:30-12:30 in F228.
Next meeting March 31st.
Join by Bluejeans by phone and computer +1.888.240.2560 (US Toll Free) Enter Meeting ID: 653182486

Need to check whether the beam pipe will allow one to go to 8-9.5 degrees. (Dave Gaskell will look into this.)
Get the Q1 mapping information from Steve Lassiter.
Need to keep track of detector surveys. Contact Bert Metzger.
Put code for setting field on wiki.
Double check to understand why there is a 0.7% difference between field at +3900A and -3900A.
Change the effective length of HB by 4% to see effects on the optics. Look at sieve.
Need table for conversion of all magnet currents to momentum.
Check with Steve Lassiter about what is exactly thinking of using to mitigate the HB stray fields. Wedges + C-section + iron pipe?
Work on run plans. (Rolf and Tanja)

Magnets.
- Determination of B versus I curve. Develop new code for setting SHMS. Revise HMS field setting codes.
- Cycling procedure especially for HB. Look what is done for the HMS.
- Double check that the magnet field between magnets are superpositions.
- Survey of the positioning of magnets.
Carbon elastics at 2 pass.
Survey of collimators, detectors and beamline components.
Survey of HMS/SHMS pointing at different angles. Look into what was done in the past for HMS commissioning. Determine a list of angles for survey.
Need to come up with the sieve pattern as a function of quad settings.
Need to look at use of ideal dipole versus TOSCA field map for HB in COSY.
Check with Howard about checking the quad field centering.
Integration of detector checkout and optics.

Results from Dipangkar for 1 pass- 2.2 GeV, and 2 pass -4.4 GeV). Measurements at 8-9.5 are doable.
Need to check whether the beam pipe will allow one to go to 8-9.5 degrees. (Dave Gaskell will look into this.)

Document and plots about mapping of B versus I at center of HB bore and the fringe fields in the beam region.
- B/I versus I plot.
Measurements of B at bore center versus I when ramping magnet from 0 to +3900 and back to 0. Then switch polarity and ramp from 0 to -3900 and back to zero.
- plot of absolute difference between B when ramping magnet up and down versus I when going to +3900 and -3900.
- plot of relative difference between B when ramping magnet up and down versus I when going to +3900 and -3900.
- Plot of difference in B between ramping up to +3900 and ramping up to -3900 versus current.
- When ramping to negative currents there was a trip at I= -3139A. Plot of difference between first ramp to -3139A and the second.
Document and plots about mapping Of B versus z for five different x,y locations (center,top,bottomleft and right) for I = 2000, 3000, 3500 and 3900A.

HMS Detector survey information,Magnet location surveys
File with B/I data and plots for dipole and quads.
Document about dipole field measurements.
Dipole Transfer Function which compares Tosca and measurements at probe and center.
Q1 Transfer Function plots and data
Q2 Transfer Function plots and data
Q3 Transfer Function plots and data
Note by Dave Mack on dipole current regulation.
Plot of Q2 predicted waist versus momentum for effects of zero offset.
Plots of quads effective field length.
Plots of quad fringe field.
Plot X_fp versus momentum.

Moved Snake section here.