From: Sunil C (sunilc@barc.gov.in)
Date: Mon Mar 05 2007 - 11:04:43 CET
Hi
OK, So if I am interested in the proton recoil then will this work?
Regards
Sunil
Vasilis Vlachoudis wrote:
> Hi Sunil,
>
> the mdstck is used to manage the stack of particles produced after an
> interaction. In elastic collisions there are no secondaries produced
> unless you have a recoil on the target nucleus e.g. if it is a hydrogen
> atom.
>
> Cheers
> Vasilis
>
> -----Original Message-----
> From: Sunil C [mailto:sunilc@barc.gov.in]
> Sent: Monday, 05 March 2007 09:37
> To: Vasilis Vlachoudis
> Subject: Re: Scoring number of elastic collissions
>
> Hi
>
> I am sorry to bother you again. I posted the query to the list but none
> replied. So I still would like to know if have a way to score the
> elastic collisions from the low energy neutron group.
> Going back to the manual CERN-2005 -10 page number 310 the MDSTACK can
> be used to analyze or write the secondaries to a file. Do you think this
>
> would work? or is there any other variable that can be tapped. I am
> trying to compare the number with a MCNP calculation.
>
> Best Regards
> Sunil
>
> Vasilis Vlachoudis wrote:
>
>> Dear Sunil,
>>
>> you have to be careful with the low energy neutrons (En<19.6 MeV), the
>> routine that I've send doesn't apply to them. It only works down to
>>
> 19.6
>
>> MeV, and not below when the neutrons are treated with the group
>> approach. Is true that you can activate point-wise treatment for some
>> elements [LOW-NEUT, what(6) card] like Hydrogen, but then the event
>>
> flag
>
>> for scoring the elastic scattering is no longer the LELEVT, but rather
>> the LLENSC for both elastic and inelastic. Otherwise, the stuprf for
>> these neutrons will be called only when there is an event that
>>
> generates
>
>> a secondary particle in the stack i.e. proton recoil.
>>
>> Best Regards
>> Vasilis
>>
>> -----Original Message-----
>> From: Sunil C [mailto:sunilc@barc.gov.in]
>> Sent: Friday, 02 March 2007 08:03
>> To: Vasilis Vlachoudis
>> Subject: Re: Scoring number of elastic collissions
>>
>> Hi
>>
>> Thanks a lot
>> If let us say the medium is hydrogen in which i need to count, the
>> energy of neutron is within the low energy group say 1 MeV then is it
>> possible to do so by switching off the inelastic collision, switch on
>> all elastic collisions by threshold card and not transporting the
>> protons so that it does not escape the region. These can be counted
>>
> with
>
>> USRBIn card. The number of protons will be more or less equal to the
>> fluence in the region. I may be wrong also because if not transported
>> the whole energy is deposited in the region. But these will not give
>>
> the
>
>> number of collissions.
>>
>> Just a train of thought
>>
>> Best Regards
>> Sunil
>>
>> Vasilis Vlachoudis wrote:
>>
>>
>>> Hi Sunil,
>>>
>>>
>>>
>>> I would do something like the following:
>>>
>>> I will use the stuprf.f routine to increase the particle variable
>>> ISPARK (1,NPFLKA) for every elastic event, like:
>>>
>>> IF ( LELEVT ) THEN
>>>
>>> * Increment number of elastic scatterings
>>>
>>> ISPARK (1,NPFLKA) = ISPARK (1,NPFLKA) + 1
>>>
>>> END IF
>>>
>>> And then use the USERDUMP with a modified MGDRAW routine to dump the
>>> ISPARK variable which at this level should become ISPUSR(1), based on
>>>
>
>
>>> the coditions: 1:falls below threshold, or 2. exists the system
>>>
>>> * Write Neutrons
>>>
>>> IF (JTRACK.EQ.8) THEN
>>>
>>> IF (ICODE.EQ.31 .OR. ICODE.EQ.12) THEN
>>>
>>> * Stopping or below threshold (POSITIVE) Unit:50
>>>
>>> WRITE (90, *) ISPUSR(1)
>>>
>>> ELSE IF(ICODE.EQ.14 .OR. ICODE.EQ.23 .OR. ICODE.EQ.32) THEN
>>>
>>> * Escapping from the geometry (NEGATIVE)
>>>
>>> WRITE (90, *) -ISPUSR(1)
>>>
>>> END IF
>>>
>>> END IF
>>>
>>>
>>>
>>> Of course you have to activate the call to userdump and set the
>>>
> proper
>
>>>
>>>
>>
>>
>>> cuts with the low-bias to stop the group treatment of the low-energy
>>> neutrons
>>>
>>> like:
>>>
>>> LOW-BIAS 1.0 73.0 1 100
>>>
>>> USERDUMP 100.0 40.0 5.0
>>>
>
>
>>> userdump
>>>
>>> OPEN 90.0
>>>
>
>
>>> UNKNOWN
>>>
>>> neutcount
>>>
>>>
>>>
>>>
>>>
>>> In the routine I am using the sign on the number of scatterings to
>>> discriminate if they fall below the threshold or they escape the
>>>
>>>
>> system.
>>
>>
>>>
>>>
>>> Cheers
>>>
>>> Vasilis
>>>
>>>
>>>
>>>
> ------------------------------------------------------------------------
>
>>
>>
>>> *From:* owner-fluka-discuss@fisica.unimi.it
>>> [mailto:owner-fluka-discuss@fisica.unimi.it] *On Behalf Of *Sunil C
>>> *Sent:* Thursday, 01 March 2007 14:00
>>> *To:* fluka-discuss@fluka.org
>>> *Subject:* Scoring number of elastic collissions
>>>
>>>
>>>
>>> Hi All
>>>
>>> I would like to count the number of elastic collissions a fast
>>>
> neutron
>
>>>
>>>
>>
>>
>>> undergoes before reaching the thermal energy. I see that this
>>> information is scored in the MDSTACK. How do i extract these
>>>
>>>
>> information?
>>
>>
>>>
>>>
>>> Best Regards
>>>
>>> Sunil
>>>
>>>
>>>
>>
>>
>>
>
>
>
>
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