Re: [fluka-discuss]: Problem with monoenergetic source

From: Agnieszka Witkowska <witkowskaagnieszka07_at_gmail.com>
Date: Wed, 4 Jul 2018 21:10:14 +0200

Dear Francesco and Alfredo,

Thank You for reply. Indeed I should change the density, I simply forgot
about it.

In real life experiment charge generated in ionization chamber was simply
scored on a anode and chamber's response for different beam energies was
compared (ratio of scores for different energies). I am trying to get those
ratios however in Fluka I cannot directly obtain current measured by
ionization chamber. I came up for the idea to score energy deposited in gas
and divide such scores obtained for different energies (I was hoping it
will show the same results as for ratio of the current).

Can You please advise how to model in Fluka this life experiment? I do not
need to get the results of the current, just the ratios. I was also
considering to use DETECT card, however I am not sure how it works.

Best regards,
Agnieszka

2018-07-03 8:53 GMT+02:00 Alfredo Ferrari <alfredo.ferrari_at_cern.ch>:

> Dear Agnieszka
>
> I am not sure it really matters for your problem, however if I understand
> your input correctly, you want to have Argon at 25 atm as sensitive gas,
> you (correctly) set the gas pressure to 25 atm with MAT-PROP, but you left
> the density in the corresponding material card to the one at 1 atm, which
> is changing quite a bit the energy deposition.
>
> Please forgive me if I misinterpreted something, I only gave a summary
> look at your input.
>
> Alfredo
> +----------------------------------------------------------------------+
> | Alfredo Ferrari || Tel.: +41.22.76.76119 |
> | CERN-EN/STI || Fax.: +41.22.76.69474 |
> | 1211 Geneva 23 || e-mail: Alfredo.Ferrari_at_cern.ch |
> | Switzerland || |
> +----------------------------------------------------------------------+
>
> On Sun, 1 Jul 2018, Agnieszka Witkowska wrote:
>
> Dear Fluka Experts,
>> I am trying to lead in Fluka real life experiment with usage of ionization
>> chamber. I am measuring energy deposited in gas of the device. in real
>> life
>> experiment source of radiation was placed 2 meters from centre of
>> ioniztion
>> chamber.
>>
>> I assume that I do not know how to define correctly beam source to make it
>> similar to real conditions. I defined monoenergic, rectangular beam with x
>> and y beam 200cm to make sure that the whole device will be surrounded by
>> radiation.
>>
>> I have obtained really strange results. With increasing energy the energy
>> deposited in each simulation is increasing as well, what does not match
>> with
>> life experiments, as in some point no more electrons should be generated
>> in
>> gas.
>>
>> Can You please check my input file and advise what I am doing wrong? Or
>> maybe I am missing some physics?
>>
>> Below I attached obtained results:
>>
>> beam energy [GeV]
>> deposited energy
>> 0,000059
>> 1,79E-08
>> 0,000186
>> 2,68E-08
>> 0,000667
>> 5,73E-08
>> 0,00117
>> 8,85E-08
>> 0,005
>> 3,07E-07
>> 0,01
>> 5,11E-07
>> 0,02
>> 7,19E-07
>> Best regards,
>> Agnieszka
>>
>>


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Received on Thu Jul 05 2018 - 08:36:00 CEST

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