sPHENIX HCal discussion

[John Lajoie <lajoie AT iastate.edu>]

Hi John,

    From the slides it looks like you fixed a thermocouple (red) between the first measurements and irradiation?  It does look like things are fairly stable when plugging/unplugging, which is nice.

    The "back of the envelope" number I recall for the total does is something like a few hundred kRads max, and I don't think that typically has large effects on scintillator. If that's the case a larger step like 50kRads might be more appropriate?

    Also, is the entire tile exposed? Or just a particular place one the tile?  If it is highly localized then it might be nice to expose two on the scintillator and two on the WLS.  Don't know how possible that might be.

John

On 7/23/2018 9:21 PM, John Haggerty wrote:

Hello,

Sorry I missed last week's meeting (my flight was canceled coming back from the family to-do).

Since I got back, I finished up some reproducibility tests I was doing before I left, and I was able to start trying to radiation damage our tiles as suggested in the CD-1 review.  I was able to do it parasitically with Takao and and John K.'s TPC electronic test.

I put some slides about it under "First Radiation Dose, July 23, 2018" on the previous agenda page:

https://indico.bnl.gov/event/4836/

I post these here now because I have another chance to expose the tiles tomorrow, and if anyone has any suggestions or insights about what to dose them to, I thought I'd give you the opportunity to weigh in, since it's a one-directional experiment.

I would probably go for another 10 or 15 krad left to my own devices.

--

John Lajoie

Professor of Physics

Iowa State University

 

(515) 294-6952

lajoie AT iastate.edu