Re: USRYIELD to look at photon emittance?

From: Francesco Cerutti <Francesco.Cerutti_at_cern.ch>
Date: Thu, 10 Nov 2011 17:13:12 +0100

Dear Mina,

USRYIELD can indeed give you the angular distribution of the photons
crossing the boundary surface between two regions, as a function of the
polar angle defined with respect to the beam direction (or a different
direction if you specify it by a further USRYIELD card with SDUM=BEAMDEF).
However in your input there are two errors:
i. if you set WHAT(1)=114.0, the angle values are expected to be input in
radians. WHAT(7)=180.0 is then wrong, unless you choose WHAT(1)=124.0.
ii. WHAT(12) is not intended only for the specific purposes you recall
(actually of no interest for you) but also for choosing the output
quantity. What you want is the plain double differential yield (like most
of the people using USRYIELD), so you must set WHAT(12)=3.0 and not to
leave the default (which involves the beam electron cross section in a
given material, making no sense)

Hope this helps

Francesco

**************************************************
Francesco Cerutti
CERN-EN/STI
CH-1211 Geneva 23
Switzerland
tel. ++41 22 7678962
fax ++41 22 7668854

On Thu, 10 Nov 2011, Mina Nozar wrote:

> Dear all,
>
> I am trying to look at the emittance of the photons emerging from a molten Lead converter placed in front of a target
> for 50 MeV electron beam with a 7.5 mm width.
>
> Can I use USRYIELD to look at the angular distribution of the photons?
>
> I used this USRYIELD card but am getting a core dump.
>
> USRYIELD 114. PHOTON -94. rPbConv rTaEnDsW PhotAD
> USRYIELD 180. 0.0 36. .05 0.0&
>
>
> I have not used USRYIELD before and am not sure it is the right estimator for this purpose.
> I left WHAT(12) (Material of the target for cross section or LET calculations) blank.
>
> Thank you,
> Mina
>
>
Received on Thu Nov 10 2011 - 18:17:02 CET

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