Field modeling

1. Field modeling J. Nelson 2/2/05 Tracking support meeting

2. Since we last met • Put out action items http://www-hep.physics.wm.edu/~jkn/minos/tracking/0501_tracking.txt • Please send comments and corrections

3. More progress • Francisco will be liaison with Bob Wands on modeling • Bob well on the way to a variable slots model • Gets rid of one functional B-B’ mapping for variable gaps • Strategizing on the end effects model • Geometry limited by number of elements • Talking with Bob about • Partial slots and gap • Gap & no slots • Fall back position is no gaps & no slots • Would need to treat the end model as a correction to original • Need to spec the conductor path in ISM gap • JKN & Francisco • Useful for mass distribution in the new geometry too • (see next page)

4. Coil Exit Geometry

5. Bfield interfaces • Talked to Robert… • Put in Jeff’s variable gap B -> B’ with parameters • Put in Jeff’s B-H variation model (also B->B’) with parameters for all plates • Plane by plane overall scale factors • Will eventually be results of • Bdot correction * Bdot calibration * global correction • 1st is the hysteresis data from the bdot system • 2nd is the channel-to-channel calibration of the bdot ADCs • 3rd muon calibration for the SM1/SM2/ND from range vs curvature • Put in Erik’s collar and coil models with parameters • Provision for Robert’s field admixture model for effects • Need to have plate-by-plate B->B’ mappings for B-H curve corrections • Eventually interface to DB table for B-H and construction information about what heat is were in a plane • Provision for modeling the air field in the SM gap in 6cm planes of air • Is this easy ???

6. Bdot system • Coordination meeting on Tuesday • Francisco has verified the can use same code for ND & FD coil control (life gets easier) • Bench test up an running at W&M • Keith (W&M UG), Francisco, and Jason Koskinen working on merging various code • Jason’s revisions to output table and timing • Jason’s input table methods • Keith’s drift calibration and current limiting code • Francisco on debugging some hardware at Soudan (time outs) • Francisco bench verification of signal • Goal is to converge by end next week • Some longer term items (ADC calibration, client server) • Running now requires a few days without beam to attempt to run • Test and them optimize run (currently 4 hours per loop) • A few days or ~4 runs • Collect production data (few hours per SM) • FD polarity put back to normal yesterday • ND magnet ran for many hours without problem • Only waiting on ND switch control with Bdot for bdot running • System fine for normal operations