[Brahms-l] run update

Dear Collaborator,

I have placed the notes from today's local meeting regarding run-progress on my RCF web page
http://www4.rcf.bnl.gov/~videbaek/brahms/index.html 

We are making good progress, and will start taking higher pt, An data at 4 deg starting when beam is back following todays beam dev. and experiments.

An open issue on the remaining runplan is that of beam development and running of the PHOBOS 405 GeV run.
Todays meeting within RHIC spin brought some clarification to this. The development and Phobos running is estimated to be 7+2 shifts (+2 -0 contingency). This is somewhat less than anticipated so far. A summary of the meeting from G.Bunce is given below. A concensus was reach to proceed with this. A final confirmation will be made at tomorrows planning meeting. This will imply that beam development for the 405 and the running will take place from Tuesday May 31 morning to sometime Friday June 3 depending on progress, in time to restore physics for that weekend.

flemming

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Flemming Videbaek
Physics Department
Brookhaven National Laboratory

e-mail: videbaek@bnl.gov
phone: 631-344-4106

-- draft summary from todays SPIN meeting.

Hello spinners--Here is my summary of our meeting today, 5/23.
Given that a decision is expected on this tomorrow, I am sending
it out in "draft" form.  However, please send me any important
corrections.
-
1. The plan to ramp to 205 GeV is recommended by Mei Bai et al.,
vs. ramping to about 135 GeV, for the development of the
spin program toward eventual 500 GeV running.  The investment to
ramp to 205 GeV vs. stopping at 135 GeV is not seen as requiring
significant extra time.  The advantage to spin is the expectation
that polarization will survive to above 135 GeV, and to test the
polarization survival up to the highest accessible energy.
-
2. Mei expects that polarization will survive to 205 GeV, with
an orbit rms of 0.5 mm.  This is the level achieved for our
100 GeV running.  Also, the expectation is that this rms can be 
achieved within the planned development time of 7 shifts.
-
3. Mei proposes then to run 2 shifts of collisions at root(s)=410 GeV.
This is focused mainly on the Phobos request, but STAR and PHENIX
would collect data also, and this is particularly useful if the
polarization survives (transverse, and with at least 1 beam
polarized).  A point here is that the only knob available to address
polarization survival is to minimize the orbit rms.  Mei expects 
that this will have already been minimized during the proposed ramp
development.
-
4. The proposal is to start this on Tuesday, May 31, and to complete
this and return to 200 GeV physics running by Friday June 3 (before the
weekend).
-
5. There was also discussion of a plan to spoil the orbit rms and to
measure the polarization survival, to be done at some future time.
The focus of this is to provide information on the margin for
polarization survival.  Thomas Roser commented that the method of
spoiling the orbit rms would be artificial and may provide only a
rough estimate of the margin.  Therefore, this plan (shown as up to
7 shifts) will be discussed after we complete the 410 GeV running.
-
I think that all spinners present bought into the above plan (1-4).
-
Gerry





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