[Crater-team] CRaTER Side Shielding

Wed Jan 2 10:54:35 EST 2019

Mark; those plots are great.  I wonder if you could re-plot them with an
x-axis maximum of 200 MeV?  That's where most of the interesting features
are, and I'd love to be able to see those more clearly.

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 Wed, Dec 26, 2018 at 3:06 PM Mark D Looper <mark.d.looper at aero.org>
wrote:

> Hello—
>
>
>
>                 Sorry, I said I was going to get to this either in the
> hotel at or on the plane returning from the AGU meeting.  I attach six
> plots, one for each of the six detectors, showing the response of each to
> protons coming in at each energy and angle.  The angle is averaged over all
> azimuths as if the sensor was cylindrically symmetrical, and there is no
> obstruction from the spacecraft in the simulation; however, enough of the
> solid angle is covered by open space in reality that this should not make
> all that much difference quantitatively, and none qualitatively.  This set
> of plots, which includes the D5 and D6 plots I sent during the discussion
> about possible neutron or gamma response some months ago, is based on the
> response simulations that I did in 2010 using Geant4 version 9.3; the
> single-detector proton response is not likely to change much when I redo
> them with version 10.5 (that is mainly aimed at understanding shrapnel and
> “scruff” in multi-detector coincidences).
>
>
>
> The colorscale is the logarithm of the effective area of that detector’s
> singles rate (with flight thresholds applied) for protons arriving at the
> given energy (X axis) from the given angle off the D6 normal (Y axis), with
> the white color denoting the full nominal area (9.6 cm^2) of each
> detector.  You can see that D3 and D4 have some off-axis leakage down to 50
> MeV or so, and that D4 in particular has a small sneak path down to about
> 20 MeV.  Let me know if you need this integrated over angle as a curve vs.
> energy or something.
>
>
>
> Happy new year—
>
> --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: *Anthony Case <tonycase at cfa.harvard.edu>
> *Date: *Thursday, December 6, 2018 at 11:12 AM
> *To: *Mark D Looper <mark.d.looper at aero.org>
> *Cc: *Harlan <spence at guero.sr.unh.edu>, "crater-team at lists.sr.unh.edu" <
> crater-team at 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 at 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 at lists.sr.unh.edu> on behalf of
> Harlan Spence <spence at guero.sr.unh.edu>
> *Date: *Thursday, December 6, 2018 at 10:53 AM
> *To: *Anthony Case <tonycase at cfa.harvard.edu>
> *Cc: *"crater-team at lists.sr.unh.edu" <crater-team at 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 at 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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>
>
>
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