Re: [fluka-discuss]: magnetic field in vacuum

From: Santana, Mario <msantana_at_slac.stanford.edu>
Date: Mon, 24 Feb 2014 12:22:02 -0800

Yes, it does.


On 2/24/14 12:20 PM, "Mina Nozar" <nozarm_at_triumf.ca> wrote:

>Thank you Mario and Francesco. I am clear on this now.
>
>I do have another question. Does FLUKA handle magnetic field through
>non-vacuum regions?
>We have a case here where the vacuum box region of a bending magnet
>upstream of the 100 kW beam dump can be filled with stainless steel.
>This is to get the back-scattered electrons shower in the s.s. region
>with the s.s. providing some attenuation for photons. The energy of the
>back-scattered electrons (going through the beam pipe is below 10 MeV.
>
>I don't see any obvious bending happening when I turn the material in
>the B field region to s.s. Maybe it is because the B field immediately
>steers the electrons into the s.s. region.
>
>Just wanted to make sure the FLUKA allows for having magnetic field
>inside a non-vacuum region.
>
>Thanks a lot,
>Mina
>
>On 14-02-18 12:43 PM, Santana, Mario wrote:
>> No, you always need to set the appropriate flag in ASSIGNMAT, regardless
>> whether you use a simple field (MAGNFIELD only) or a programmed one
>> (magfld.f) .
>>
>
>On 14-02-18 11:50 AM, Francesco Cerutti wrote:
>>
>> Not at all. A region will be considered as magnetic only if it is
>> declared as such in the respective ASSIGNMAT card. And the reason for
>> that is what I indicated below as second and more important argument.
>>
>> Cheers
>>
>> Francesco
>>
>> **************************************************
>> Francesco Cerutti
>> CERN-EN/STI
>> CH-1211 Geneva 23
>> Switzerland
>> tel. ++41 22 7678962
>> fax ++41 22 7668854
>> On 2/18/14 11:17 AM, "Mina Nozar" <nozarm_at_triumf.ca> wrote:
>>
>>> Dear Francesco,
>>>
>>> So do I understand correctly that if one needs to assign/associate a
>>> magnetic field to a region of interest in the ASSIGNMAT card, if one
>>> uses the MAGNFIELD card for a simple magnetic field setting but NOT if
>>> one uses the magfld.f to set and assign the magnetic field to a given
>>> region.
>>>
>>> Thanks and best wishes,
>>> Mina
>>>
>>> On 14-02-14 12:57 PM, Francesco Cerutti wrote:
>>>> Dear Mina,
>>>>
>>>> first of all we just saw with Brandon that, if you are fine with a
>>>> constant field, you do not need to write a magfld.f routine but it is
>>>> enough to define it in the MGNFIELD card. Then ASSIGNMAT is essential
>>>> to tell the code in which regions that field should be applied.
>>>>
>>>> Furthermore and more important, you definitely do not want to ask the
>>>> code to go always through the magnetic tracking algorithm - by far
>>>> more complex than a straight step - despite the fact that no magnetic
>>>> field is present in your region, and to call the magfld.f routine at
>>>> each substep to get back a humiliating zero.
>>>>
>>>> Ciao
>>>>
>>>> Francesco
>>>>
>>>> **************************************************
>>>> Francesco Cerutti
>>>> CERN-EN/STI
>>>> CH-1211 Geneva 23
>>>> Switzerland
>>>> tel. ++41 22 7678962
>>>> fax ++41 22 7668854
>>>>
>>>> On Fri, 14 Feb 2014, Mina Nozar wrote:
>>>>
>>>>> Hello Francesco and everyone else.
>>>>>
>>>>> Just trying to understand the flow/logic of assigning magnetic fields
>>>>> in a region.
>>>>>
>>>>> Here is my understanding and a question where I lack understanding...
>>>>>
>>>>> 1) MGNFIELD card activates calling the subroutine MAGFLD defined in
>>>>> mgfld.f
>>>>> 2) In subroutine MAGFLD, one defines the intensity and direction of
>>>>> the magnetic field(s) and assigns it to a given region(s).
>>>>> 3) Set Field to Magfiled in the ASSINMAT card for the region(s) with
>>>>> magnetic field.
>>>>>
>>>>> What I don't understand is why do we need to turn on magnetic field
>>>>> in the ASSIGNMAT card? Is this not already set via MAGFLD?
>>>>>
>>>>> Best wishes,
>>>>> Mina
>>>>>
>>>>> On 14-02-14 01:57 AM, Francesco Cerutti wrote:
>>>>>> Hallo,
>>>>>>
>>>>>> actually, in case of constant magnetic field in all magnetic
>>>>>> regions, the
>>>>>> MGNFIELD card is enough (as stated in the manual). It will
>>>>>> automatically
>>>>>> feed the default magfld routine (the one provided in usermvax,
>>>>>> where in
>>>>>> fact the comment
>>>>>> * 2 Tesla uniform field along +z:
>>>>>> does not apply) and you do NOT need to link the latter into a
>>>>>> customized
>>>>>> executable, unless you want to modify it, since it is already in
>>>>>>the
>>>>>> standard FLUKA library and linked in the standard executable.
>>>>>>
>>>>>> Cheers
>>>>>>
>>>>>> Francesco
>>>>>>
>>>>>> **************************************************
>>>>>> Francesco Cerutti
>>>>>> CERN-EN/STI
>>>>>> CH-1211 Geneva 23
>>>>>> Switzerland
>>>>>> tel. ++41 22 7678962
>>>>>> fax ++41 22 7668854
>>>>>>
>>>>>> On Thu, 13 Feb 2014, Dr. Vittorio Boccone wrote:
>>>>>>
>>>>>>> No you should still include and link the default magfld routine
>>>>>> which is
>>>>>>> configured for a uniform magnetic field, as explained in the
>>>>>> lecture and > the
>>>>>>> tutorial.
>>>>>>> Best
>>>>>>> V.
>>>>>>> Sent from my iPad
>>>>>>>> On 13/feb/2014, at 22:42, "REDDELL, BRANDON D. (JSC-EV511)"
>>>>>>> <brandon.d.reddell_at_nasa.gov> wrote:
>>>>>>>> Thanks Vittorio.
>>>>>>>> So in my simple problem, I am not using the magfld.f
>>>>>> routine,
>>>>>>> just only the MGNFIELD card. So, could you confirm if these
>>>>>>> cards should work:
>>>>>>>> MGNFIELD 20.0 0.2 0.10 0.0
>>>>>>> 0.0 1.0
>>>>>>> STEPSIZE 0.5 0.0 VAC2 0.0
>>>>>>> 0.0 0.0
>>>>>>> EMF
>>>>>>> EMF-OFF
>>>>>>> .
>>>>>>> .
>>>>>>> .
>>>>>>> ASSIGNMA VACUUM VAC2 1.0
>>>>>>> (the 1 here is at WHAT(5)
>>>>>>>> Thanks.
>>>>>>>> Brandon
>>>>>>
>>>>>>_____________________________________________________________________
>>>>>>__
>>>>>> _____
>>>>>>>> From: Vittorio Boccone [dr.vittorio.boccone_at_ieee.org]
>>>>>>> Sent: Thursday, February 13, 2014 2:47 PM
>>>>>>> To: REDDELL, BRANDON D. (JSC-EV511);
>>>>>>>fluka-discuss_at_fluka.org
>>>>>>> Subject: Re: [fluka-discuss]: magnetic field in vacuum
>>>>>>>> Sure, check out the magnetic field exercise (solution) on the
>>>>>> advanced
>>>>>>> course:
>>>>>>>
>>>>>>
>>>>>>http://www.fluka.org/fluka.php?id=course&sub=program&navig=2&which=tr
>>>>>>iu
>>>>>> mf20
>>>>>>>> 12
>>>>>>> Best
>>>>>>> V.
>>>>>>>> On 2/13/2014 8:47 PM, REDDELL, BRANDON D. (JSC-EV511) wrote:
>>>>>>>> FLUKA Users/Experts,
>>>>>>>>>> Do the magnetic field settings in a region (using
>>>>>> MGNFIELD
>>>>>>> card along with WHAT card 5 in ASSIGNMA Card) work if the
>>>>>>> region of the B field is a vacuum?
>>>>>>>>>> Brandon
>>>>>>>>>>
>>>>>
>>
>
Received on Mon Feb 24 2014 - 22:25:35 CET

This archive was generated by hypermail 2.3.0 : Mon Feb 24 2014 - 22:25:37 CET