Fall 2016 optic plans

Back to [Fall 2016 DVCS run plan]

Assuming we only need one detune setting for the new Q1.

This proposition has been made on the basis of Winter 2016 run plan, and experience of what happened and what was really used.

Proposition of LHRS run plan (still needs to be integrated with RHRS run plan)

LHRS step	Approximate beam time	Goals
L1 (sieve)	1h	20 uA DIS with sieve slit on optics foils
L2 (no sieve)	1h	Delta Elastic on LH2, 20 uA

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One pass program

E_beam= 2.217 GeV
LHRS θ_e=16.5 deg
LHRS DAQ: S2+Cer (T3), Use LHRNEW for DAQ configuration. See [section 5.2 in DVCS shift howto] for complete procedure!.  
Energy and position lock should be on.
The DVCS calorimeter HVs need to be off

==== Step L1: Procedure with Sieve-slit (DIS) ====
The DVCS calorimeter HVs need to be off
P₀= 1.0 [GeV/c] (DIS)
If the LHRS goes to a new higher momentum setting, Q2 and Q3 need to be cycled.
Q²= 0.182 GeV²
W= 1.727 GeV

	LEFT Q1 Current	Q1	Estimated Rates	estimated time	actual rates	run number	#event in the run
Target	[A]	detune	[Hz] at 20 uA		[Hz] at 20 uA
Optics no raster	?	1.000	300	1h (or at least 100k events)

==== Step L2: Delta Scan with Proton Elastic (sieve) ====

The DVCS calorimeter HVs need to be off

If the LHRS goes to a higher momentum setting, Q2 and Q3 need to be cycled.  

LHRS θ_e=16.5 deg
We are going to need to check the rates before we take these data, to be safe. But from experience from Winter 2016, 20 μA should be ok.
Run duration 5-7 minutes each from Winter 2016 experience (we want at least 10k electron events).

Target: 15cm LH2
k' [GeV]	LQ1 Current [A]	Q1 detune	Delta P [%]	run number	number of trigger
2.1	?	1	1.04
2.06	?	1	1.02
2.02	?	1	1.00
1.98	?	1	0.98
1.94	?	1	0.96