Hello—

                Yes – I’ll look at them on the airplane and/or in the hotel.

See you next week—

--Mark

Mark D. Looper
Space Sciences Department
The Aerospace Corporation
M/S M2-260
P.O. Box 92957
Los Angeles, CA 90009-2957
Mobile: 310-529-3406
Voicemail: 310-336-6302

From: Anthony Case <tonycase@cfa.harvard.edu>
Date: Thursday, December 6, 2018 at 11:12 AM
To: Mark D Looper <mark.d.looper@aero.org>
Cc: Harlan <spence@guero.sr.unh.edu>, "crater-team@lists.sr.unh.edu" <crater-team@lists.sr.unh.edu>
Subject: Re: [Crater-team] CRaTER Side Shielding

Mark,

In comparing with GOES, we were curious about he response to >50 MeV protons, since GOES has a data product that is integral flux above 50 MeV.  Specifically, we were wondering if 50 MeV protons could make it through the side of the instrument into D3/D4. In looking at the mechanical design, it seemed like there were some paths where protons with energies less than 50 MeV (maybe even down to 30 MeV) could make it through to the detector.  Do you have model runs that would answer that question?

Tony

---------------------------------------------------------------------

Anthony Case

Astrophysicist

High Energy Astrophysics Division (HEAD/SSXG)

Center for Astrophysics | Harvard & Smithsonian

Cell: (617) 304 0768

60 Garden Street | MS 58 | Cambridge, MA 02138

On Thu, Dec 6, 2018 at 4:02 PM Mark D Looper <mark.d.looper@aero.org> wrote:

Hello—

                I’m sorry I missed the call yesterday because of Aerospace AGU dry runs at the same time.  What is the specific question about side penetrators that was asked?  I can dig response functions vs. energy and angle out of my 2010 sensor-head simulations, though I’ll probably have to do it from my hotel room at AGU.  I do intend to port the code to the current version of Geant4 and re-run it, for use in the paper after the one containing the work I’m summarizing on the AGU poster, but for protons the results won’t change much.

--Mark Looper

Mark D. Looper
Space Sciences Department
The Aerospace Corporation
M/S M2-260
P.O. Box 92957
Los Angeles, CA 90009-2957
Mobile: 310-529-3406
Voicemail: 310-336-6302

From: Crater-team <crater-team-bounces@lists.sr.unh.edu> on behalf of Harlan Spence <spence@guero.sr.unh.edu>
Date: Thursday, December 6, 2018 at 10:53 AM
To: Anthony Case <tonycase@cfa.harvard.edu>
Cc: "crater-team@lists.sr.unh.edu" <crater-team@lists.sr.unh.edu>
Subject: Re: [Crater-team] CRaTER Side Shielding

I love it when a plan comes together.  We meant to do that!  I guess it was in the instrument paper for a reason….too many years now.

________________________________

Harlan E. Spence

Director, Institute for the Study of Earth,

   Oceans, & Space and Prof. of Physics 
Morse Hall, Room 306 
University of New Hampshire

8 College Road

Durham, NH 03824-3525

Phone: 603-862-0322

Fax:   603-862-1915

http://www.eos.unh.edu/Faculty/Spence
________________________________

On Dec 6, 2018, at 2:36 PM, Anthony Case <tonycase@cfa.harvard.edu> wrote:

Since we were discussing the possibility of side-penetrators yesterday, I went back and looked at the solid model for the instrument to see how much shielding is on the sides of the detectors.  There are a couple images attached.  The outer wall of the telescope housing is 0.2 cm, and the added shielding was essentially a C-channel with 0.2cm walls that was bolted onto the outside of the telescope housing.  So for normally incident particles there is just the end-caps which are 0.076 cm (which gives us our usual ~10-12 MeV protons required to get into the instrument).  And for side-penetrators to get through a 0.4cm thick wall requires about 27.5 MeV.  That neglects the detector frame, which could add another >0.5 cm.  Of course any particular particle's path through all of this junk is fairly complex, but roughly speaking 30-50 MeV seems like the minimum energy a side-penetrating proton would need to reach the detector.

<image.png>

<image.png>

---------------------------------------------------------------------

Anthony Case

Astrophysicist

High Energy Astrophysics Division (HEAD/SSXG)

Center for Astrophysics | Harvard & Smithsonian

Cell: (617) 304 0768

60 Garden Street | MS 58 | Cambridge, MA 02138

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