Star-fst-l mailing list

["Ye, Zhenyu" <yezhenyu AT uic.edu>]

Besides low lumi zero field, should we take low lumi full field data for 
alignment?
This is a question and I don’t know the answer.

Zhenyu

> On Jan 14, 2022, at 4:41 PM, videbaek <videbaek AT bnl.gov> wrote:
> 
> Hi Elke,
> 
> we discussed two itesm
> 1) low luminosity about 10M events. Running it with the 50M NSD seems 
> perfect and the goal should easily be met.
> 2) We do have sufficient low-lumi runs already for space charge 
> calibration, so no additioanlrequests, but #1 wil help.
> 3)The zero filed tracking alignment do not help the TPC but is of course 
> important.
> 
> Gen,Yuri and Flemming
> 
> 
> On 2022-01-14 12:56, Carl Gagliardi wrote:
>> Hi Flemming and Gene--  I don’t know what low lumi statistics are
>> required by the TPC group.  But if 50M+ NSD collisions with field on
>> will suffice, then the forward cross sections data could likely serve
>> double duty.
>> A thought…
>> Carl
>> p.s.  Note:  The statistics estimate above is based on the assumption
>> that a high fraction of the EPDE&&TOFmult0 events will be NSD
>> collisions, with a z_vtx distribution that follows the collision
>> diamond.
>>     We haven’t been in a position to test that assumption yet.  But
>> the converse has been tested for a mix of semi-hard to hard
>> scattering.  In particular, Bassam finds that EPDE&&TOFmult0 has
>> low-to-mid 90s% efficiency for all of the existing FCS triggers, with
>> only 1~2% variation trigger to trigger.  Also, when running at low
>> lumi, Bassam has found that 98% of the FCS-triggered events that
>> include TPC read-out contain a good vertex.
>> From: Carl Gagliardi <c-gagliardi AT tamu.edu>
>> Sent: Friday, January 14, 2022 10:28 AM
>> To: 'Aschenauer Elke-Caroline' <elke AT bnl.gov>; 'STAR sTGC upgrade'
>> <star-stgc-l AT lists.bnl.gov>; 'Star-fst L' <star-fst-l AT lists.bnl.gov>;
>> 'Carl Gagliardi' <c-gagliardi AT tamu.edu>; 'Flemming Videbaek'
>> <videbaek AT bnl.gov>; 'Van Buren, Gene' <gene AT bnl.gov>
>> Subject: RE: low luminosity running
>> Hi Elke—
>> The forward MB cross sections measurement will need 16 hours of beam
>> with magnet on and __very low__ luminosity.  Specifically, the
>> non-singly diffractive collision rate per bunch should be no more than
>> a few percent.  2%/bunch would be great; we should be able to live
>> with 4%/bunch if C-AD can’t get down further.  Under these
>> conditions, there is no value in having more than 6 bunches in the
>> fill.  Motivation:
>> 6 bunch fills at 2%/bunch corresponds to about 9400 NSD collisions per
>> second.  The TPC, which will provide vertexing and measure the
>> in-bunch pile-up, will only be able to record 2 kHz or thereabouts.
>> (At these very low rates, that might be pushed to 2500 Hz (TBD), but
>> not more.)  6 bunches will easily saturate that; more will only
>> increase the background activity in the TPC with no benefit for the
>> measurement.
>> Note:  9400 NSD collisions per second correspond to a ZDC coincidence
>> rate of 800-900 Hz.
>> Side note:  These total and recorded collision rates aren’t
>> “new”.  They are in fact very similar to the values we adopted to
>> optimize the isobar studies in 2018.
>> The beam lifetime might be quite long under these conditions.  If the
>> entire data set can be recorded in one very long fill, that will be
>> fine.  Otherwise, two fills should be more than adequate.
>> To achieve the highest practical final precision, we should request
>> that a Vernier scan be performed in conjunction with the measurement.
>> Finally, a personal concern:  Beginning next week, I will be out of
>> pocket teaching class on Tuesdays and Thursdays from 10:15-12:15 BNL
>> time.  I don’t need to watch the entire running period from Texas,
>> and likely won’t.  But I definitely think it would be useful for me
>> to be online for at least the first hour or two of each fill.  I hope
>> that can be factored into the scheduling.
>> Hope this is clear!
>> Carl
>> p.s.  If C-AD believes it could reliably deliver the beams with a
>> collision rate of 1%/bunch crossing (even better!), then a 12-bunch
>> fill would be desired.
>> p.p.s.  I only expect us to have two “physics triggers” in the
>> runs, EPDE singles and (EPDE && TOFmult0).  However, there will also
>> be a number of other highly prescaled trigger-detector only triggers
>> to facilitate normalization using the TCU scalers.
>> From: Aschenauer Elke-Caroline <elke AT bnl.gov>
>> Sent: Thursday, January 13, 2022 10:02 PM
>> To: STAR sTGC upgrade <star-stgc-l AT lists.bnl.gov>; Star-fst L
>> <star-fst-l AT lists.bnl.gov>; Carl Gagliardi <c-gagliardi AT tamu.edu>;
>> Flemming Videbaek <videbaek AT bnl.gov>; Van Buren, Gene <gene AT bnl.gov>
>> Cc: Aschenauer Elke-Caroline <elke AT bnl.gov>
>> Subject: low luminosity running
>> Dear All, as you know the next week we will most likely have lower
>> luminosity and polarization as there is an issue with the APS. So this
>> might be the perfect time to take our alignment data for the FST and
>> the sTGC. So the requirement was ZjQcmQRYFpfptBannerStart
>> This Message Is From an External Sender
>> This message came from outside your organization.
>> ZjQcmQRYFpfptBannerEnd
>> Dear All,
>> as you know the next week we will most likely have lower luminosity
>> and polarization as there is an issue with the APS.
>> So this might be the perfect time to take our alignment data for the
>> FST and the sTGC.
>> So the requirement was one fill with 28 bunches and low bunch current,
>> with Magnet off. Do we have a luminosity number we want for this.
>> Is one fill enough.
>> Are there any measurements we need to do before we are ready for this
>> alignment run.
>> Carl you wanted low luminosity running for the cross section
>> measurement in the forward region, I assume you want it with magnets
>> on.
>> Can you please remind me about the exact conditions you want.
>> Are there any measurements we need to do before we are ready for this
>> low lumi run.
>> Flemming and Gene there was also some request for low lumi running for
>> the TPC if I remember correctly, can you remind me what lumi you want
>> and what conditions.
>> I would appreciate to have all the info by tomorrow CoB Friday
>> 01/14/2022
>> Thanks elke
>> _Note: Please do not feel obligated to respond to this message outside
>> of your work hours._
>> ( `,_' )+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-
>>  )    `\                                                      +
>> /    '. |        Elke-Caroline Aschenauer  (she/her/hers)      =
>> |       `,                                                      -
>>  \,_  `-/        Brookhaven National Lab                         +
>>  ,&&&&&V         Physics Dept.,            25 Corona Road         =
>> ,&&&&&&&&:       Bldg. 510 /2-195          Rocky Point, NY,        -
>> ,&&&&&&&&&&;      20 Pennsylvania Avenue                 11778       +
>> |  |&&&&&&&;\     Upton, NY 11973
>> =
>> |  |       :_) _  Tel.:  001-631-344-4769   Tel.:   +1-631-569-4290
>> -
>> |  |       ;--' |                           Cell-USA:  +1-757-2565224
>> +
>> '--'   `-.--.   |                           Cell-Europe:
>> +49152220025211 =
>>   \_    |  |—‘
>>       -
>>     `-._\__/     Mail: elke AT bnl.gov        elke.caroline AT me.com
>>    +
>> +=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=-+=
> 
> -- 
> Flemming Videbaek
> senior scientist
> videbaek @ bnl.gov
> Brookhaven National Lab
> Physics Department
> Bldg 510D
> Upton, NY 11973
> 
> phone: 631-344-4106
> cell     :  631-681-1596
> _______________________________________________
> Star-fst-l mailing list
> Star-fst-l AT lists.bnl.gov
> https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.bnl.gov%2Fmailman%2Flistinfo%2Fstar-fst-l&amp;data=04%7C01%7Cyezhenyu%40uic.edu%7C1ef4aede58674492b48008d9d7af1380%7Ce202cd477a564baa99e3e3b71a7c77dd%7C0%7C0%7C637777969229998253%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&amp;sdata=EMJ7k8J4%2BiQWFWY5Ose6wnup1MoxO6D8AN8H9A6cMec%3D&amp;reserved=0

Attachment: smime.p7s
Description: S/MIME cryptographic signature