[Olympus] PRC70 - report

[Belostotski, Stanislav]

Dear Frank and colleagues,
On order to answer all the questions in the list( given below by Frank =

in his mail) of possible sources of false asymmetry in our experiment =

there must be done serious MC studies.I did a simple estimation only one =

item in the list: false asymmetry due to uncertainty in vertical and =

horizontal beam slope at the I.P. (attached file). The false asymmetry =

is calculated with the help of r(theta)=3DN'(theta)/N(theta)(1/deg.) functi=
on
plotted versus e-scattering angle in the attached file.
For example for 12deg.Lumi monitor r=3D0.3 (1/deg.). If slope uncertainty =

is 0.01 deg. ->  delta_theta =3D 0.01 deg.(azimuthal accep. is small for =

12deg.Lumi Monitor)
the false asymmetry is 0.3%.
We may continue discussion on other uncertainties at the meeting. With =

best regards stanB


On 21.10.2010 11:28, Brinker, Frank wrote:
> Dear Richard, dear colleagues,
> It's good to hear that the PRC is supporting us and the points you
> mentioned are reasonable and need our attention.
> I can say, that it's planned for the 4th of november in the next service
> week to try to test electron operation of the LINAC, the accumulator
> ring and maybe the DESY synchrotron. Accelerating electrons with the
> LINAC should be easy, but it'll take some time to establish procedures
> for switching back and forth  effectively and reproducible.
> The first runs with electrons in DORIS will be possible in February next
> year. It would be great, if the test experiment would be ready to take
> data - even if it's not fully equiped at that time.
>
> I have also some questions to you concerning the needed repeatablity of
> the beam parameters - during the runs, from run to run and especially
> from e- to e+.
> To calculate the error bars of the final e+/e- ratio "R" we need to know
> the dependencies of R on the beam parameters - or other way round to
> determine the needed precision to reach our goal.
>
> Therefore the question is: What is the dependence of R on
> - beam energy
> - beam position
> - beam angle
> - horizontal and vertical emittance
> - bunch length
> - background ( scattered particles from dust )
> - differences of ion/electron densities within the target due to
> different electric field of the beam
>
> We'll try to determine the accuracy of the parameters for the next
> Olympus meeting. If someone could give numbers for the dependencies we
> would see where we are standing and whether we need to improve things.
>
> With best regards
> Frank Brinker
>
>
>
>> -----Original Message-----
>> From: olympus-bounces at MIT.EDU [mailto:olympus-bounces at MIT.EDU]
>> On Behalf Of Richard G Milner
>> Sent: Friday, October 15, 2010 7:07 AM
>> To: olympus at MIT.EDU
>> Subject: [Olympus] PRC70 - report
>>
>>
>> Dear OLYMPUS colleagues,
>> This is a short note to report on the presentation and
>> discussion in open and closed session to the DESY PRC which
>> took place here at Zeuthen yesterday.  It went well.  The PRC
>> was `very impressed with the considerable progress on the
>> OLYMPUS experiment and congratulated the collaboration.?  In
>> closed session, discussion focused on the following points:
>>
>> -	Keeping the OLYMPUS target installation to the tight schedule
>> -	Choosing soon the optimal 12 deg. lumi monitor GEM configuration
>> -	Making it a priority for DESY to provide electron beam
>> in DORIS to the OLYMPUS
>> test experiment
>> -	Development of the analysis software in a timely way
>> -	Preparing a detailed plan (inc. milestones and
>> manpower) for the test
>> experiment
>>
>> The discussion was reasonable and supportive.  I thank all who
>> have worked hard to put our experiment in such a favorable
>> position. Of course, there is an intensive period ahead but
>> DESY will support us in every way it can to guarantee success.
>> Finally, thank you to all who sent me slides.  My
>> presentation in open session is attached.
>>
>> With best regards,
>> Richard
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