Date: Wed, 7 Sep 2016 15:16:17 +0200
Hi Francesco,
Yes I see more yield of alphas depositing their energy on the silicon
sensor after reducing the thickness of the metallization layer.
I wish to also see if I capture any protons on the silicon with the Lithium
conversion layer. Do I need to enable any special cards for the same or I
can simply select the PART in the USRBIN as protons and run the simulations?
[image: Inline images 2]
Thanks in advance.
Cheers,
Shri
(Srinidhi Bheesette)
On 6 September 2016 at 22:32, Srinidhi Bheesette <srinidhi.bheesette_at_cern.ch
> wrote:
> Hi Francesco,
>
> Yeah hopefully I should be able to see more alphas on the silicon detector
> now.
>
> And yes! I have now figured out a way to get the range.
>
> Thanks for your continued support. :)
>
> Cheers,
> Shri
>
> (Srinidhi Bheesette)
>
> On 6 September 2016 at 20:22, Francesco Cerutti <Francesco.Cerutti_at_cern.ch
> > wrote:
>
>>
>> Well, 4 micron change definitely the picture, since alphas above 1 MeV can
>> make it.
>>
>> At the NIST link, you have just to select the material, click on Submit,
>> and you will get a table giving stopping power and range (you care about
>> the latter) as a function of the alpha kinetic energy. Units are for mass
>> length, so you need to rescale them by the material density
>>
>> Best wishes
>>
>> Francesco
>>
>> **************************************************
>> Francesco Cerutti
>> CERN-EN/STI
>> CH-1211 Geneva 23
>> Switzerland
>> tel. ++41 22 7678962
>> fax ++41 22 7668854
>>
>> On Tue, 6 Sep 2016, Srinidhi Bheesette wrote:
>>
>> > Hi Francesco,
>> > Thanks for the reply.
>> >
>> > After reading some papers I found out that the thickness of the
>> > metallization layer is 4 microns.
>> >
>> > Inline images 1
>> > I hope this thickness is enough for the alphas to penetrate through the
>> > Aluminium metallization layer and reach the Silicon layer.
>> >
>> > Also I can figure out how to evaluate stopping power on the link you
>> sent
>> > me. Please help. Thanks in advance.
>> >
>> > [f18dQhb0S7ks8dDMPbW2n0x6l2B9gXrN7sKj6v4f9HlVRYvr-7fJZTzN3Lq
>> Z7CQFLCHW2rmRCv
>> > 1k1H6H0?si=4558345310568448&pi=4742b69d-2ceb-47ec-e936-8e9eb633db44]
>> >
>> > Cheers,
>> > Shri
>> >
>> > (Srinidhi Bheesette)
>> >
>> > On 5 September 2016 at 13:07, Francesco Cerutti <
>> Francesco.Cerutti_at_cern.ch>
>> > wrote:
>> >
>> > Hi Shri
>> >
>> > with 20 micron Al, likely you will not see anything again, since
>> > 5 MeV
>> > alphas can just make it (only if travelling in the good
>> > direction) and
>> > your alphas are indeed less energetic.
>> >
>> > Kind regards
>> >
>> > Francesco
>> >
>> > **************************************************
>> > Francesco Cerutti
>> > CERN-EN/STI
>> > CH-1211 Geneva 23
>> > Switzerland
>> > tel. ++41 22 7678962
>> > fax ++41 22 7668854
>> >
>> > On Mon, 5 Sep 2016, Srinidhi Bheesette wrote:
>> >
>> > > Hi Francesco,
>> > >
>> > > I am sorry, yes, I mean now I can score on the conversion
>> > layer.
>> > >
>> > > Thanks for the link, its really useful.
>> > > Just for a test I ran a job by assigning vacuum to the
>> > metalization layer and I observed
>> > > that I am able to score on the silicon sensor as well. I will
>> > now try to assign it
>> > > Aluminum again, reduce the thickness to 20 microns and run
>> > again.
>> > >
>> > > Thanks very much for your help. :)
>> > >
>> > >
>> > >
>> > >[f18dQhb0S7ks8dDMPbW2n0x6l2B9gXrN7sKj6v4f9HlVRYvr-7fJZTzN3
>> LqZ7CQFLCHW2rmRCv
>> > 1k1H6H0?si=4
>> > > 558345310568448&pi=aaa52f34-4cc8-45d7-d851-b4047fa205b2]
>> > >
>> > > Cheers,
>> > > Shri
>> > >
>> > > (Srinidhi Bheesette)
>> > >
>> > > On 4 September 2016 at 21:59, Francesco Cerutti
>> > <Francesco.Cerutti_at_cern.ch> wrote:
>> > >
>> > > Dear Shri,
>> > >
>> > > I'd guess from the context of your message that you
>> > actually meant "I am
>> > > NOW [rather than NOT] able to score alphas(4-He) on the
>> > conversion layer"
>> > > and I'd be happy for that.
>> > > About the fact that the generated alphas do not make the
>> > silicon detector,
>> > > it looks indeed logical due to metalization: a 5 MeV
>> > alpha - more
>> > > energetic than what you get out of thermal neutron
>> > capture on 6Li - has a
>> > > range of 20 micron in aluminum, as you can see on NIST
>> > >
>> > (http://physics.nist.gov/PhysRefData/Star/Text/ASTAR.html).
>> > >
>> > > Cheers
>> > >
>> > > Francesco
>> > >
>> > > **************************************************
>> > > Francesco Cerutti
>> > > CERN-EN/STI
>> > > CH-1211 Geneva 23
>> > > Switzerland
>> > > tel. ++41 22 7678962
>> > > fax ++41 22 7668854
>> > >
>> > > On Sun, 4 Sep 2016, Srinidhi Bheesette wrote:
>> > >
>> > > > Hi Francesco,
>> > > > Thank you very much for you reply.
>> > > > I have made the necessary changes and I am not able to
>> > score alphas(4-He)
>> > > on
>> > > > the conversion layer. But I still don't get any hits
>> > on the Silicon
>> > > detector
>> > > > layer which is separated from the conversion layer
>> > (Lithium) by a 40
>> > > microns
>> > > > metalization layer made of Aluminium (sorry I did not
>> > mention this in my
>> > > > previous mail).
>> > > >
>> > > > Is the metalization a problem or do I need to make
>> > more changes so that it
>> > > I
>> > > > can score on Silicon too?
>> > > >
>> > > > Thanks in advance.
>> > > >
>> > > [f18dQhb0S7ks8dDMPbW2n0x6l2B9gXrN7sKj6v4f9HlVRYvr-7fJZTzN3
>> LqZ7CQFLCHW2rmRC
>> > v
>> > > >
>> > 1k1H6H0?si=4558345310568448&pi=d2713f3f-ab03-475e-a465-69e4
>> fbc8836d]
>> > > >
>> > > > Cheers,
>> > > > Shri
>> > > >
>> > > > (Srinidhi Bheesette)
>> > > >
>> > > > On 3 September 2016 at 13:12, Francesco Cerutti
>> > > <Francesco.Cerutti_at_cern.ch>
>> > > > wrote:
>> > > >
>> > > > Hi Shri,
>> > > >
>> > > > please read the manual, LOW-NEUT card, Note 5.
>> > > >
>> > > > In particular, you need to have pointwise
>> > treatment activated
>> > > > (which is
>> > > > already the case for PRECISIO defaults) as well
>> > as a LiF
>> > > > compound
>> > > > definition containing explicitly the LITHIU-6
>> > material as
>> > > > elemental
>> > > > component. The latter has to be in turn defined
>> > by a MATERIAL
>> > > > card
>> > > > specifying monoisotopic composition (see again
>> > the manual and
>> > > > avoid the
>> > > > usual mistake mixing up the mass number in
>> > WHAT(6) - which is
>> > > > what you
>> > > > have to fill, with the number 6.0 - and the
>> > atomic weight in
>> > > > WHAT(2) - not
>> > > > to be filled at all -).
>> > > >
>> > > > Note in addition that your PART-THR card makes
>> > no sense, since
>> > > > 1eV is
>> > > > patently not an option as transport threshold,
>> > being 1keV the
>> > > > hard cutoff
>> > > > for everything but neutrons and photons.
>> > > > And, as a general rule, do not limit the full
>> > transport to
>> > > > 4-HELIUM only,
>> > > > as you did with IONTRANS, rather let it be
>> > applicable to all
>> > > > heavy
>> > > > and light ions (put HEAVYION, i.e. particle code
>> > -2, as
>> > > > explained in the
>> > > > manual).
>> > > >
>> > > > Best
>> > > >
>> > > > Francesco
>> > > >
>> > > >
>> > **************************************************
>> > > > Francesco Cerutti
>> > > > CERN-EN/STI
>> > > > CH-1211 Geneva 23
>> > > > Switzerland
>> > > > tel. ++41 22 7678962
>> > > > fax ++41 22 7668854
>> > > >
>> > > > On Sat, 3 Sep 2016, Srinidhi Bheesette wrote:
>> > > >
>> > > > > Hi all,
>> > > > > I wish to score alphas produced by the
>> > reaction of thermal
>> > > > neutron( 0.025eV)
>> > > > > with Lithium Fluoride moderator.
>> > > > >
>> > > > > I am using a 0.025eV neutron point source for
>> > my simulations
>> > > > and scoring the
>> > > > > a silicon detector which is bonded to the
>> > moderator.
>> > > > > I have enabled the transport using the
>> > following card
>> > > > >
>> > > > > IONTRANS 4-HELIUM
>> > > > >
>> > > > >
>> > > > > and also changed the threshold to 1eV for
>> > alphas using the
>> > > > following card:
>> > > > >
>> > > > > PART-THR -1.E-9 4-HELIUM
>> > 0.0
>> > > > >
>> > > > >
>> > > > > Finally I score the flux on the moderator
>> > using the following
>> > > > card:
>> > > > >
>> > > > >
>> > > > > USRBIN 10. 4-HELIUM 22.
>> > 0.700067 0.880124
>> > > >
>> > > > > -0.10convalp
>> > > > >
>> > > > > USRBIN -0.702433 -0.5261 -0.11
>> > 256. 256.
>> > > >
>> > > > >
>> > > > > 1. &
>> > > > >
>> > > > >
>> > > > > and on the silicon detector using the
>> > following card:
>> > > > >
>> > > > >
>> > > > > USRBIN 10. 4-HELIUM 29.
>> > 0.700067 0.880124
>> > > > 0.10sialph
>> > > > >
>> > > > > USRBIN -0.702433 -0.5261 -0.096
>> > 256. 256.
>> > > > 1. &
>> > > > >
>> > > > >
>> > > > > But in vain, as I do not see any alpha
>> > particles scored. The
>> > > > fort files are
>> > > > > filled all with zeros.
>> > > > >
>> > > > > Please let me know where I am going wrong.
>> > Help would be
>> > > > greatly
>> > > > > appreciated.
>> > > > >
>> > > > > Thanks in advance.
>> > > > >
>> > > > > Cheers,
>> > > > > Shri
>> > > > >
>> > > > > (Srinidhi Bheesette)
>> > > > >
>> > > > >
>> > > >
>> > > >
>> > > >
>> > > >
>> > >
>> > >
>> > >
>> > >
>> >
>> >
>> >
>> >
>>
>
>
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