[Brahms-l] pp polarized development run

The pp run was all along setup to be a development run with 3 priorities
a) develop new working point
b) luminosoty development and
c) jet target commisioning and measurements

It has been quite apperent in the last few days that progress has been
slower than anticipated, so the time set aside for datataking stores will be
used for machine dev and jet target comm.

Thus ALL experiments are on standby with a fairly high chance of no further
datataking this run.
Thus ALL shift scheduled are cancelled at this point, though there may be a
(small) chance for get one or
two more over-nights. I enclosed an assesment of the status from Gerry
Bunche

All together we got a reasonable set of reference spectra, but very little
for the pol program at 2.3 deg.

flemming

----------------------------------------------------------------
Flemming Videbaek
Physics Department
Brookhaven National Laboratory

e-mail: videbaek@bnl.gov
phone: 631-344-4106
----- Original Message ----- 
From: "Gerry Bunce" <bunce@bnl.gov>
To: "Mei Bai" <mbai@bnl.gov>
Cc: "Peter Steinberg" <peter.steinberg@bnl.gov>; "Fleming Videbaek"
<videbaek@bnl.gov>; "Dana Beavis" <beavis@bnl.gov>; "Alessandro Bravar"
<bravar@bnl.gov>; "Mark Baker" <mdbaker@bnl.gov>; "Les Bland"
<bland@bnl.gov>; "Abhay Deshpande" <abhay@bnl.gov>; "Gerry Bunce"
<bunce@bnl.gov>; "Thomas Roser" <roser@bnl.gov>; "Yousef Makdisi"
<makdisi@bnl.gov>; "Derek Lowenstein" <lowenstein@bnl.gov>
Sent: Friday, April 30, 2004 11:08 AM
Subject: where we are on a concensus


> Hello Mei--After our discussion at 9 today, I found Dana and
> reached Mark by phone.  The plan we are discussing is to
> run through the weekend to Monday with the jet using the blue
> beam and CAD using the yellow beam for polarization studies.
> There would be no collisions at the experiments.  We discussed
> ramps possibly every 2 to 3 hours for the polarization studies.
>
> We have always emphasized three goals for this run:
>
> 1. study luminosity limits, develop a new working point if possible
>
> 2. study polarization in RHIC
>
> 3. commission and make a first jet measurement
>
> Then, we have always wanted to try to get data with the experiments.
> Both Phenix and Star have emphasized the primacy of the goals above.
>
> Where are we?
>
> On 1:
> The new working point works.  We have achieved 1.7 x 10^11/bunch
> collisions with 4 IPs, and good lifetime.  The tune shift has
> been measured.  I believe that this means we now know that we
> can reach 2 x 10^11/bunch with 2 IPs.
>
> Vacuum intensity limit issues--still need to study this.  (Presumably
> starting Monday)
>
> On 2:
> We have never studied the polarization in RHIC until this year.  We
> have had a number of curious results so far--snake settings not as
> expected, evident polarization lifetime this year, possible radial
> polarization at flattop seen by the CNI last year in blue, and seen
> by STAR this year.  There is a severe polarization profile, both
> vertically and horizontally.  We have a very nice snake scan at injection,
> working tune measurements, working polarization measurement
> on the ramp.  In short, we are progressing and learning, and we
> have the necessary tools.
>
> On 3:
> The jet is a beautiful device.  It works.  We are part way toward
> a significant A_N(pC) absolute measurement.  Sandro gave the numbers
> Wednesday.  It needs to be emphasized that we are calibrating the
> pC CNI polarimeters, and that any result will be improved with higher
> polarization, both from statistics and from systematic uncertainties.
> I believe that the number that we do get will be applicable to
> previous runs (recall that we have no 100 GeV calibration of the
> polarization and that the 22 GeV calibration has DP/P = +/-30%).
> Therefore, this measurement will be important for the existing
> experimental data.
>
> It is my view that item 2, polarization study, should be emphasized.
> Your compromise of collecting data on the jet while studying P seems
> like our best plan.
>
> I also understand that no overnight running would be planned for next
> week.  However, you would need to have collisions to study L, but
> polarization would be ignored.
>
> Gerry
>
> As for the plan for next week, I would like to understand it better.
> For one thing, it would be very useful to have a number from the jet
> at 24 GeV.
>


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