Optics Meeting Oct 29 2024 0100PM ET

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Agenda

1. Quick update on sieve power deposition (Kate) [1]
2. Kinematic factor update (Vassu)
3. Review of Evan's magnetic field study progress (Kate/David for Evan) [2]

Attendance

Vassu, Kate, David, Zuhal, Paul S., Sayak

Minutes

1. (Kate): At Mike Dion's request, Kate has re-checked earlier power deposition studies in the blocker (and sieve), now with the final as-built geometries for each. No surprises, the worst case is the blocker with 5-pass beam on the long lH2 target: 19.9 W/muA (earlier version from March 22 was 18.9 W/muA). Also checked power deposition for sieve under same conditions: 19.4 W/muA, a little smaller, as expected, since the sieve has holes. Also checked sieve with thin optics targets at 4-pass beam: 0.113 W/muA for Optics 1 (Upstream) and 0.090 W/muA for Optics 2 (Downstream), and 1-pass beam with optics 1 (0.576 W/muA). Upstream target larger than Downstream since less of cone of scattered beam makes it through the hole in the sieve; presumably wider cone of scattered particles for 1-pass than 4-pass, so more scattered flux in sieve in that case. All seems to make sense. Both sieve and blocker will be actively water cooled.
2. (Vassu): Looking into whether our algorithm for determining the kinematic factor for Moller electrons will be affected/distorted by the eP elastics (and inelastic eP) events. The background fraction in ring 5 from non-Mollers is about 9%. Will try to see if a) including these events messes up kinematic factor and b) if it does, can we reject these tracks using some combination of r and r', or find a way to correct for their effect.
3. (Kate, for Evan Jackson): Developing scripts to look at how location of tracks from sieve holes (with 12C target) changes when B-field is distorted in controlled manner. See what appear to be smooth dependence for holes near the shifted coil in azimuth, but no effect for holes in farther sectors, as expected. Need to add error bars to plots. However, something odd about the shifted-field maps (as provided by Buddhika) compared to the "symmetric field": that one is not in the center of the dependence, and is "off" noticeably even for holes away from shifted coils. Will check with Buddhika/Juliette. May make sense to generate an "almost symmetric" map in the same way as the shifted coil maps, but with the coil shift being very small (0.001 mm, for example).

Meeting link information

See email invitation, or contact David Armstrong, Kate Evans, or Ciprian Gal for Zoom link