Re: Kolb's quenching parametrization

Dear Anna,

thank you so much for a comprehensive reply. I need the corrected for
quenching energy deposition in MGDRAW; I'm using the following solution
for the moment:

1) In USERDUMP with SDUM=UDQUENCH Birks setting parameters B1=A/2,
B2=0, here A is the only parameter of Wright's parametrization;
2) comparing quenched and non-quenched values extra extracting A*dE/dX
and so obtaining the quenched value for Wright's parametrization.

Best regards,

Vassili

On 04/12/2010 01:11 AM, Anna Ferrari wrote:
> Dear Vassili,
>
> the treatment of the quenching is implemented in FLUKA, up to
> now, only following a second order Birks parametrization.
> In this case it can be set directly in the input card.
>
> You want to use the Wright parametrization, that foresees only one
> parameter (eq.5 in the Kolb article): even if this is the case, I think
> that it's useful to briefly remind, first, how to proceed in the case of
> a correction 'a la Birk'. This could help to better address a solution in
> your case.
>
> In general the quenching correction must be applied at two different
> levels:
>
> a) to the binned energy, that is scored via USRBIN or EVENTBIN:
> in this case you use the TCQUENCH card (see the manual);
> b) in the track reconstruction, to the deposited energy along the track:
> in this case you have to use the USERDUMP card, with sdum=UDQUENCH;
> what(2) and what(3) will be the first and the second Birks parameters,
> in g/(MeV cm2) (see the manual also in this case).
>
> As I understood, the two corrections are absolutely independent: if you
> are interested only to score the track variables, you can also not to use
> the first card.
> Let'see, now, how to retrieve the quenched values in the case b).
> In mgdraw.f you have to save the corrected values both along the track
> steps and for a "spot" deposition, that means:
> 1) in MGDRAW, by doing the sum of the 'quenched' depositions along the
> track. Instead of summing the original energy depositions dtrack(k)
> (with k=1,...mtrack) you have to sum the corresponding quenched
> values, that are simply given by the dtquen(k,1) output variable of the
> QUENMG routine (the second number refers to the fact that you can load
> more than one set of parameters, here I refer to the set 1).
> The routine above is called because the setting as in b) forced the
> LQEMGD variable to be .TRUE.
>
> 2) in ENDRAW, by considering, in the same way, the value of dtquen(1,1)
> (here the first 1 means that we have only one "spot" deposit)
> instead of the value of the variable 'rull'.
>
> Let's come, now, to your correction. First of all: QUENMG is not a user
> routine and you cannot modify it.
> You can think to act on the energy deposits: you don't activate the
> quenching via USERDUMP and you apply your correction BOTH to the dtrack(k)
> energy depositions in MGDRAW and to the 'rull' spot deposition in ENDRAW.
> BUT: while the first correction is (maybe) easy to do, I have doubts about
> the meaning of the second one (maybe the authors can hlp us). What I know
> is that the treatment of the quenching in case of spot depositions
> is not trivial to compute, because we have always to do assumptions,
> depending of the kind of spot. For example a spot can be due:
> - to particles under the transport thereshold (dE/dx is in this case set to
> the remaining energy);
> - to residual nuclei recoils (dE/dx is inthis case rescaled
> from the corresponding value, of a proton of the same energy);
> - to charged particles generated from low energy interactions, that are not
> in general transported (they are transported only for interactions
> on hydrogen and few others): in this case dE/dx corresponds to their
> production energy; .....
>
> For this kind of complexity, I don't know if a meaningful correction
> can be done simply in ENDRAW...
>
> Hope it helps,
> Anna
>
>
>
>> Dear FLUKA experts,
>>
>> I wanted to implement the quenching parametrization proposed by N.R.Kolb
>> et al (NIM-A 368, 1996, pp.745-749), but didn't find where I can get
>> dE/dx (or, what is equivalent, the "energy deposition length") for each
>> energy deposition. What common is used by QUENMG?
>>
>> Regards,
>>
>> Vassili
>>
>> P.S.: Actually the parametrization I want to use is proposed by
>> G.T.Wright,
>> Phys. Rev. 91 (1953) 1282.
>>
>>
>>
>
>
Received on Mon Apr 12 2010 - 13:53:12 CEST