sPHENIX HCal discussion

[John Lajoie <lajoie AT iastate.edu>]

Hi John,

    Thanks for the summary, and the Herculean efforts of everyone involved to close of test beam 2018b.

    Regarding positive running for the energy scan, I agree it is not necessary.  With the limited time and effort available concentrating on a negative energy scan with some 120GeV data for the steel and Al iHCAL is a lot to do already.

John

On 5/2/2018 10:01 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