[Clas12_first_exp] RC meeting at 2:30

Stepan Stepanyan stepanya at jlab.org
Sun Oct 14 12:34:33 EDT 2018


Hello Mac,

No argument, 45 nA will be fine. As you noticed, my “efficiency” and the figure-of-merit plot that shows peak at 50 nA for 3-prong events assume 100% tracking efficiency for beam current =0. Of course it is not true, so the real optimum is bit less than 50 nA.

Regards, Stepan
  
> On Oct 14, 2018, at 12:03 PM, Mac Mestayer <mestayer at jlab.org> wrote:
> 
> Good work - now negatives and positives give
> the same results.
> 
> Regarding the optimum - you optimized for production
> rate, but I'd like to point out that there will be
> a systematic error associated with the efficiency
> correction, and this error is probably proportional
> to the size of the correction.
> 
> Sorry to be a bummer and bring up systematic errors !  :{
> 
> Anyway, that effect and the fact that the drift chambers
> are running fairly high DC HV currents, would argue for
> ~ 45 nA maximum, in my opinion.
> 
> regards, Mac
> 
> ----- Original Message -----
> From: "Stepan Stepanyan" <stepanya at jlab.org>
> To: "clas12 first exp" <clas12_first_exp at jlab.org>
> Sent: Saturday, October 13, 2018 10:14:23 PM
> Subject: Re: [Clas12_first_exp] RC meeting at 2:30
> 
> Dear all, 
> 
> I run the same studies for tracking efficiency using positively and negatively charged track multiplicity at different currents. The beam current dependence of tracking efficiency is improved compared to previous studies with data processed in August. Details can be found at - 
> https://logbooks.jlab.org/entry/3608949 
> 
> Optimum beam current for 3-prong evens is 50 nA. 
> 
> Stepan 
> 
> 
> 
> 
> 
> On Oct 8, 2018, at 3:04 PM, Francois-Xavier Girod < fxgirod at jlab.org > wrote: 
> 
> Dear all 
> 
> In the logbook the path indicated to the data files for the luminosity scan set is incorrect 
> 
> The correct path for the 2 nA files are 
> /work/clas12/clas12/data/fall18/cooked/out_clas_pin_004893.evio.*.hipo 
> 
> The other runs are in the same directory, the runs are 
> 4893 2 nA 
> 4895 4 nA 
> 4887 10 nA 
> 4888 25 nA 
> 4956 45 nA 
> 4900 60 nA 
> 4899 75 nA 
> 
> Best regards 
> FX 
> 
> On Mon, Oct 8, 2018 at 7:38 PM Rafayel Paremuzyan < rafopar at jlab.org > wrote: 
> 
> 
> Hi all, 
> 
> sorry for late notice, 
> 
> We will have an RC meeting today at 2:30 PM to 
> discuss the status and plans for the run. 
> The room is the meeting room in the 2nd floor in the counting house. 
> Bluejeans linkhttps:// bluejeans.com/7572697303 
> 
> Rafo 
> RC 
> 
> _______________________________________________ 
> Clas12_first_exp mailing list 
> Clas12_first_exp at jlab.org 
> https://mailman.jlab.org/mailman/listinfo/clas12_first_exp 
> _______________________________________________ 
> Clas12_first_exp mailing list 
> Clas12_first_exp at jlab.org 
> https://mailman.jlab.org/mailman/listinfo/clas12_first_exp 
> 
> 
> _______________________________________________
> Clas12_first_exp mailing list
> Clas12_first_exp at jlab.org
> https://mailman.jlab.org/mailman/listinfo/clas12_first_exp




More information about the Clas12_first_exp mailing list