[Poltarg12] Getting ready for RG C ERR...

[kuhn]

Dear all,

at present, we are scheduled to have our first Experiment Readiness Review during the last week of March. Given the short time left, we discussed asking to move this date about 2 months later so we can have more actual results (and pieces of equipment!) ready for presentation. However, even so, it is high time for us to get started on serious preparations for the ERR. In the following, I am listing some of the required jobs (please add your 5 cents!!!) and - as far as I know - responsible people for each of these jobs. If you want to get involved in one of these, please contact one of the listed workers/leads. AND MAKE AN EFFORT TO ATTEND THE NEXT RG C meeting (which, unfortunately, will only occur in January). If you are at all interested in the target aspects, please join our polarized target meetings as well - the next one will take place next week Thursday.

1.) Experimental Set Up
1.a) Polarized target: Design and construction status, remaining tasks, benchmarks and test results, target material (irradiation!), installation and commissioning plans, slow controls, safety review (design authority), operation and safety manuals (TOSP, SOM, ESAD, ERG, COO).
LEAD: Chris Keith WORKERS: James Brock, James Maxwell, Victoria Lagerquist, Dustin Keller, Will Brooks/UTFSM
1.b) Raster system: Maximum raster radius, time constant and driver
WORKERS: Fernando Barbosa (driver), Tony Forest (LEAD?) and Victoria Lagerquist (magnets, power supplies, beam optics)
1.c) Møller shield: Possible modifications of existing shield (FTOff configuration) for rastered beam
WORKERS: Tony Forest, Angela Bisellii, S.K.

2) Background simulations
2a) FTOn configuration: Find optimum combination of target radius (= raster radius + 1 mm), target length, total luminosity, and running conditions to
i) maximize figure of merit (average squared polarization times luminosity times (1 - deadtime due to anneals)
ii) keep backgrounds in FT and DCs to acceptable level (defined by tracking efficiency > 70-80%)
2b) FTOff configuration: Find optimum figure of merit (including possibly refined Møller shield - see 1.c) for this case
WORKERS: Silvia, Angela, Tony

3) Tracking performance: what is the vertex resolution that we can expect WITHOUT FMT? Do we need FMT? Updates to tracking software in either case? 
WORKERS: Silvia, Tony,…

Depending on the outcome of 1-3, we agreed to come up with a proposal for two different running conditions (roughly split between the two halves of the expected run time for the first installment of RG C):
I) FTon with long, “skinny” single target cell, optimized for photon detection in the FT
ii) FToff with two separate cells separated by 2-3 cm, optimized for high-Q2 DIS and SIDIS.
For both cases, we will need to optimize the relative fraction of outbending vs. inbending torus polarity.
With these scenarios, we need to simulate the expected physics impact for the major components of RG C =>

4. Physics Simulations
i) SIDIS: LEAD Tony Forest, WORKERS ?
ii) DVCS: LEAD Silvia and Angela, WORKERS ?
iii) Inclusive (can be extrapolated from SIDIS and proposal numbers): LEAD Sebastian
iv) Pb*Pt measurements with elastic ep coincidences

5. Radiation safety: We will need a FLUKA simulation of the whole set up, with both configurations, both for standard luminosity and for the case where we cold-irradiate the ND3 target. VOLUNTEERS?

6. Run Plan (including anneals, target replacement, auxiliary measurements etc.) and documentation
LEAD: SK

Your comments are eagerly awaited! - Sebastian