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-7fJZTzN3LqZ7CQFLCHW2rmRCv1k1H6H0?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-7fJZTzN3LqZ7CQFLCHW2rmRCv
> > 1k1H6H0?si=4558345310568448&pi=d2713f3f-ab03-475e-a465-69e4fbc8836d]
> >
> > 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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Received on Mon Sep 05 2016 - 14:37:38 CEST