Just a minor correction to my below email: it should read
"theta being the polar angle" (and not "azimuthal")
cheers
Stefan
On Fri, 22 Aug 2014, Stefan Roesler wrote:
> Dear Hayley
>
> USRYIELD/What(6) is an user-defined normalization factor; if you leave it
> empty it is assumed to be 1. It has nothing to do with What(4) of the
> continuation card which is the upper scoring limit of the second quantity.
>
> Just to be sure: do you indeed what to score USRYIELD in pseudorapidity,
> which is -ln(tan(theta/2)) (theta being the azimuthal angle)?? It must peak
> at large values (small theta) for (scattered) beam-particles.
>
> USRBDX always scores energy spectra (in your case with one energy bin it is a
> single value). In case you define several angular bins you get as many
> "spectra" as angular bins (in your case 100). If you select in Flair 1.x (I
> recommend to go to Flair 2.x) under "Det" the second option "2 1 scatter 2D"
> you will see the different values as function of angle.
>
> Cheers
> Stefan
>
>
>
> On Fri, 22 Aug 2014, hayley.smith_at_stfc.ac.uk wrote:
>
>> Thank you very much for your help Stefan, it has been much appreciated - I
>> am now able to run the deck without it crashing.
>>
>> As a follow up, you say it is important to input values for all WHATs. In
>> this case, are you able to advise what value I should put for WHAT (6) of
>> the first USRYIELD card? It says in the manual 'normalisation factor'.
>> Would this be the same as WHAT (4) in the continuation card?
>>
>> Also, I am confused by the output I get from the USRYIELD and USRBDX cards.
>>
>> I would have thought that to score the angular distribution using USRYIELD
>> that the maximum angle would be Pi/2. However when I do this I get strange
>> results. The result seems more sensible for a maximum angle of 2Pi, but
>> still I would have expected the peak of the angular distribution to be
>> around 0, rather than around 2Pi? Am I misinterpreting my results?
>>
>> With the USRBDX scoring solid angle I understand why the maximum angle for
>> this would be 2Pi. However, the results I obtain for angular distribution
>> for a single energy bin are just as confusing to me...
>>
>> I have read extensively through the manual and previous posts but have not
>> been able to find any information.
>> I understand that a difference between USRBDX and USRYIELD is that USRBDX
>> calculates the angle with respect to the normal, and USRYIELD calculates
>> the angle with respect to the beam direction (in my case). Maybe this is a
>> source of my confusion?
>>
>> Are you able to explain:
>> Why the result of USRYIELD with a maximum angle of 2Pi is centred around
>> 2Pi?
>> Why using a maximum angle of Pi/2 in USRYIELD in this case is seemingly
>> incorrect?
>> Why I am struggling to get a meaningful result from USRBDX (or why/how I am
>> misinterpreting the results)?
>>
>> My input file and three screenshots showing the resulting graphs I describe
>> are attached.
>> Any help is very much appreciated,
>> Hayley
>>
>>
>>
>>
>>
>> -----Original Message-----
>> From: Stefan Roesler [mailto:sroesler_at_mail.cern.ch]
>> Sent: 20 August 2014 09:42
>> To: Smith, Hayley (STFC,RAL,ISIS)
>> Cc: fluka-discuss_at_fluka.org
>> Subject: Re: [fluka-discuss]: USRBDX and USRYIELD
>>
>> Dear Hayley
>>
>> I recommend to enter input values for all What's in scoring cards. Some
>> have default values, some don't.
>>
>> For example in your case WHAT(4) of the USRYIELD continuation card (upper
>> limit of the second quantity) has no default (!) which causes the code to
>> crash (normalization with an undefined value..)
>>
>> Furthermore, when the upper energy limit in USRBDX and USRYIELD is not
>> defined, the code uses the beam energy. However, when scoring BEAMPART the
>> energy of the particle to be scored is exactly at the bin limit, and
>> depending on the internal rounding the particle might be scored or not.
>> Thus, I suggest you define an upper energy limit that is slightly above the
>> beam energy.
>>
>> Cheers
>> Stefan
>>
>>
>> On Mon, 18 Aug 2014, hayley.smith_at_stfc.ac.uk wrote:
>>
>>>
>>> Dear All
>>>
>>>
>>>
>>> I am trying to look at the scattering of a 800 MeV proton beam through
>>> a carbon target. (At present the beam distribution and target
>>> geometry are very much simplified).
>>>
>>> I have tried to score the angular distribution of the proton beam in
>>> two ways, using USRBDX and using USRYIELD.
>>>
>>>
>>>
>>> I thought USRYIELD would be the most appropriate since I read various
>>> threads on the forum, and this one in particular seemed to be doing a
>>> very similar thing to me,
>>> http://www.fluka.org/web_archive/earchive/new-fluka-discuss/0568.html
>>>
>>>
>>>
>>> However, when I try to create a USRYIELD card with a single energy bin
>>> the progress status for the run always ends after the first cycle with
>>> ?Finished with ERRORS? and nothing stands out to me from the .log,
>>> .out or .err files.
>>>
>>>
>>>
>>> When I don?t use a USRYIELD card the USRBDX card outputs results,
>>> however I am unsure how to interpret them in terms of beam scattering or
>>> divergence.
>>>
>>> The relevant files are attached for your information.
>>>
>>>
>>>
>>> Is anyone able to advise me on how best to score the beam divergence
>>> through the target?
>>>
>>> Is my approach correct? What is causing the run to finish with errors
>>> (that I can?t seem to find in the output files)?
>>>
>>>
>>>
>>> Thanks, any assistance is much appreciated,
>>>
>>> Hayley
>>>
>>>
>>>
>>>
>>>
>>> Hayley Smith
>>>
>>>
>>>
>>> Accelerator Physicist
>>>
>>> ISIS Facility
>>>
>>> Rutherford Appleton Laboratory
>>>
>>> Harwell Oxford
>>>
>>> OX11 0QX
>>>
>>>
>>>
>>> 01235 445524
>>>
>>> hayley.smith_at_stfc.ac.uk
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> --
>>> Scanned by iCritical.
>>>
>>>
>>>
>>>
>>
>> --
>> Scanned by iCritical.
>
Received on Mon Aug 25 2014 - 11:37:20 CEST