1. S. Stepanyan (JLAB) HPS collaboration meeting May 3 – 5, 2017 JLAB
2018 Run
S. Stepanyan (JLAB)
HPS collaboration meeting
May 3 – 5, 2017 JLAB
----- Meeting Notes (9/27/11 07:19) ---
Many thanks to organizers for invitation to participate in the conference and give this talk on GPD program at JLAB.

2. S. Stepanyan, HPS Collaboration meeting, JLAB, May 2017
Old beam-time request
BTR for the time period ending December 2018 was submitted on July/26/2016
Request was for total of 57 PAC days (114 days/16 weeks on the floor):
25 days at 2.2 GeV – commissioning 4 days, production data taking 21 days
32 days at 4.4 GeV – commissioning 4 days, production data taking 28 days
From what we know (as of the last fall) HPS was tentatively scheduled for 70 days on the floor for June 2018, with low energy CEBAF, ~1 GeV/pass
Multiple Hall running is planed, conflicts for beam energy with other Halls are possible. Note: only one Hall can run on passes 1 to 4.
The 70 days on the floor is 5 PAC weeks, enough for one beam energy. May need more than few days for commissioning due to the upgrades
S. Stepanyan, HPS Collaboration meeting, JLAB, May 2017

3. S. Stepanyan, HPS Collaboration meeting, JLAB, May 2017
New beam-time request
The next deadline for beam-time request will be in July, 2017
Proposed modifications require to have ERR before we can submit the beam time request
Patrizia Rossi, Deputy AD for physics, agreed to have HPS upgrade ERR on June 12, small review for few hours
We should send description of our upgrade, couple of pages, in the next week or so in order for her to organize the review
Schedule for 2018 is unknown, may not be know for quite while
We should think about a new strategy for the run and beamtime request, clearly must be longer run per beam energy (>4 PAC weeks) with sufficient time (2 PAC weeks) for L0 and trigger commissioning
S. Stepanyan, HPS Collaboration meeting, JLAB, May 2017

4. S. Stepanyan, HPS Collaboration meeting, JLAB, May 2017
Options for 2018
If summer running with low energy CEBAF will be possible (best option), 2 GeV, 3 GeV, and 4 GeV are available (in the tentative schedule 1 GeV was assigned to Hall-A PREX experiment)
The summer running will not be more than 5-6 PAC week, barely enough for one energy
High energy CEBAF operations is expected to be ~24 weeks per year (12 PAC weeks of beam time)
If no summer running, than should aim for fall 2018 or spring 2019, each ~6 PAC week beam time (still single energy run)
S. Stepanyan, HPS Collaboration meeting, JLAB, May 2017

5. S. Stepanyan, HPS Collaboration meeting, JLAB, May 2017
Reach and beam energy
experimental Hall D
CEBAF
Does not seems there is much difference in reach between 2.2 GeV and 4.4 GeV, at least in the bump hunt
~4. GeV is a new energy, can entertain idea of m+m- final state
Should decide on this before June ERR, definitely should have clear idea beam July btr
LERF
injector
experimental Halls A, B and C
S. Stepanyan, HPS Collaboration meeting, JLAB, May 2017

6. S. Stepanyan, HPS Collaboration meeting, April 2016, SLAC
Things to keep in mind for the next run (independent of when it will happen)
The bemline is different:
New collimator and more shielding downstream of the tagger dipole
Beampipe inside through the tagger (better for vacuum, more background during the beam tune)
New location of 2H00, 10ft upstream from its 2015/2016 position
Detector (CLAS12, FT) installed on the beam line
Tungsten shield inside the torus hub
Most likely forward carriage will be in upstream, CLAS12 running position. 2H02 cannot be mounted on forward carriage anymore, new stand will be needed
Slow controls, should adopt current Hall-B system
DAQ mostly the same, possibly a new trigger if approved
(not a complete list!)
S. Stepanyan, HPS Collaboration meeting, April 2016, SLAC