sPHENIX EMCal discussion

[John Haggerty <haggerty AT bnl.gov>]

John,

I forgot to mention that I asked Mandy before I left to let us know when 
we can squeeze in another short period of running.  I think we can get 
more than enough data in a few days, depending on how we have to share 
the beam.  I'll let you know when I have more information, and thanks in 
advance to anyone who could help out on this.

On 5/8/18 9:48 AM, John Lajoie wrote:
> Hi John,
>
>      Wow, thanks for the Herculean effort!
>
>      Is there a plan to return to take the Al frame data as well as the 
> HCAL cosmics in the future? ISU has some students we can send to FNAL to 
> help out.
>
> John
>
>
> On 5/8/2018 6:10 AM, John Haggerty wrote:
> > Here is a summary of running after I sent around the email below. 
> > Again, thanks to Eric, Martin, Songkyo, and Debbie for making this 
> > possible.
> >
> > - Eric and I had no problem getting the EMCAL onto the IHCAL
> >
> > - The accelerator gods did not smile down on the plan to take data 
> > with the steel IHCAL and then swap it out for aluminum; there were 
> > vacuum problems in the MI Thursday going into Friday morning that made 
> > it so we couldn't start the steel data until Friday morning, and by 
> > then it was too late to get Todd's help rigging the calorimeters 
> > around.  After talking it over with John L., we decided we'd get data 
> > with the instrumented steel.
> >
> > - I had some parasitic running with T992 on Friday which was useful to 
> > align the hodoscope with the beam.  The EMCAL and HCAL were decently 
> > close to where we wanted them, as far as I could see.  I collected 
> > quite a bit of 120 GeV p running for aficionados of high energy.
> >
> > - Friday night, we removed as much material upstream as we could. 
> > Unfortunately, Lorenzo could not get everything out of the beam in the 
> > 1a area (there were detectors with short cables with their electronics 
> > not very well supported), so I had to live with it. Lorenzo estimated 
> > that the central part of the beamline had maybe a quarter radiation 
> > length of material, but he wasn't sure how large the open aperture was 
> > before the beam hit support plates of indeterminate thickness.  Sigh.
> >
> > - Forging ahead to strains of "You can't always get what you want," on 
> > Friday night and Saturday I did and energy scan, -4, -8, -12, -16, 
> > -20, -24, -28, -30.
> >
> > - Reaching the highest energy possible in the low energy pion mode, I 
> > asked them to switch to pion mode and go to 40 GeV.  They worked on it 
> > for an our or two, and could not get that mode to work (we were 
> > getting about 600 events per spill, which I recorded, but it wasn't 
> > right, and I should have known that Saturday afternoon is not a good 
> > time to try something that hasn't been done in a while.
> >
> > Anyway, we got what energy scan data we could which is described in 
> > the elog and the run index:
> >
> > > https://www.phenix.bnl.gov/WWW/sPHENIX/haggerty/t1044/2018b/index.php
> >
> > On 5/2/18 11:01 PM, John Haggerty wrote:
> > > As I mentioned in the HCAL meeting today, we think we have finished 
> > > the EMCAL running we wanted on the 2c motion table, due to the 
> > > efforts of Eric, Martin, Songkyo Lee, and Debbie Israel, so tomorrow, 
> > > we plan to move the EMCAL and attach it to the steel version of the 
> > > Inner HCAL.
> > >
> > > The short summary of the data sets are:
> > >
> > > > dual channeling position (Fri Apr 27 19:06:25 2018)
> > > >   - energy scan 1883-1954
> > > >   - position scan 1957-2043
> > > > sphenix+5 (Sun Apr 29 10:02:25 2018)
> > > >   - energy scan 2045-2167
> > > >   - position scan 2168-2263
> > > > sphenix (Tue May 1 17:57:48 2018)
> > > >   - position scan 2280-2360
> > > >   - energy scan 2361-still running
> > >
> > > During the day, we will be sharing time with T992.  I think they will 
> > > be running 120 GeV protons, so we can just let it record data in 100k 
> > > runs all day.  About 6pm, we'll go to an energy scan HCAL+EMCAL 
> > > running. Looking at the 2017 data sets, it looks like 400k events at 
> > > -4, -6, -8, -12, -16, -24, -28 would be the minimal data set we 
> > > want.  We can take about 9k events/spill at energies where that is 
> > > possible, so 400k is about an hour at the higher energies.  If we 
> > > have more time, I would guess we would be best served getting higher 
> > > statistics at -4 and -8, although there are logistical problems 
> > > getting the Cerenkov pressures to where they need to be if we go high 
> > > and then want to go low. Also, we did comparable positive running 
> > > last year; if we want that again, we might want to reduce statistics 
> > > to squeeze it in, but my recollection is that it wasn't particularly 
> > > illuminating. I suggest we try to run for 12 hours up to Friday morning.
> > >
> > > Friday morning, Todd said he could help me crane the aluminum HCAL, 
> > > or HCAl, into place, we could do the 120 GeV thing during the day, 
> > > and again at 6pm switch to a copy of the energy scan only but with 
> > > aluminum in there.  I can finish that up Saturday before I leave on 
> > > Sunday morning if all goes well.
> > >
> > > Of course, plans can change due to various circumstances... but let 
> > > us know here if that sounds reasonable; the die is cast to move the 
> > > EMCAL early tomorrow, but we have until tomorrow night to settle on a 
> > > run plan for the EMCAL+HCAL energy scan.
>
>
> *John Lajoie*
>
> Professor of Physics
>
> Iowa State University
>
> (515) 294-6952
>
> lajoie AT iastate.edu
>
>
>
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--
John Haggerty
email: haggerty AT bnl.gov
cell: 631 741 3358