2015-09-15 m1 optics discussion¶

Notes¶

We went through Rogers slides. Came up with following job list:

0. Finish outstanding optics studies + optimisation routines (Rogers)
1. Investigate optics settings for "Hold SSU at 4T, degrade only SSD" etc (Rogers)
2. Send Ryan some currents and beams settings to look at MC of "asymmetric" setting (Rogers)
3. Run MC (Bayes/Liu)
4. Look at tracker resolution vs Bz (Bayes/Liu)
5. Look at Demo options (Pasternak/Lagrange)
6. Validate optics study (Blackmore)

Nb: It might make sense to pull in Chris Hunt to help out with the tracker resolution study.

While everything is "wild", it probably makes sense to talk reasonably frequently. Can we regroup on Thursday at noon?

p	mode	FC	M1_DS	M2_DS	M1_US	M2_US	E1_US	CC_US	E2_US	E1_DS	CC_DS	E2_DS	comment
200	solenoid	60	0	210.93	76.03	79.06	234	274	253	234	274	253	This is a not derated solenoid mode; it should have reasonably good beam quality, but will heat - the beta function is large in FC
200	flip	67.5	0	275.91	110.95	147.97	23.4	27.4	25.3	23.4	27.4	25.3	This is a flip mode; it should have reasonably good beam quality and will cool - but note that the field in the tracker is down to 0.4 T which is pretty low, so tracker reconstruction will be poor

Use

• 200 MeV/c beam
• no momentum spread
• transverse emittances of 3, 6, 10 mm (try all three)
• start the beam in the upstream tracker region (e.g. 2300 mm from absorber centre) using constant_solenoid mode on the beam and the expected bz
• Don't bother tracking through the beamline/quadrupoles.

Use two configurations;

• no materials at all, only fields (equivalent set physics_model none)
• full materials

Return, following cut on PID == -13

• Transmission(z)
  and then plotting only particles which are transmitted into the downstream tracker region
• Emittance(z)
• Beta(z)
• angular momentum(z)