Re: [fluka-discuss]: muon production frm gamma conversion or positron annhilation

From: belgin pilišer <belginpilicer_at_gmail.com>
Date: Sun, 10 Nov 2013 22:12:50 +0100

Hello experts,

I attached my input file. Now muon production is possible but it is not
correct spectrum.

I don't know MUCARLO but if you sent the code I can try to understand. Or
where can I find the code?

And just I want to simulate the positron annihilation to muon. Is it
possible with MUCARLO?

Thanks for your advance.
b.


2013/11/10 Lewis Keller <keller_at_slac.stanford.edu>

> Hi Alberto,
>
> For the very special case where the positron beam is near the fixed
> target threshold of 43.7 GeV for two-muon production AND the target
> is only a few tenths of a radiation length so that the EM shower
> hasn't fully developed, this process is more than two orders of
> magnitude larger than Bethe-Heitler production for muon laboratory
> momenta of about half the beam energy.
>
> Right now I don't have a scholarly reference, but I'm attaching a
> short .pdf file showing the formula for the muon production cross
> section as a function of the positron beam energy. At fixed target
> threshold the total cross section is about two microbarns. The cross
> section is maximum at threshold and falls as one over the square of
> the center-of-mass beam energy (as those who have worked at
> e+e- colliders are familiar).
>
> This process is in MUCARLO but it needs the positron track length for
> the beam energy and target being studied. So one first needs to get
> the positron track length (and photon track length if needed for
> Bethe-Heitler production) from FLUKA and transfer that to MUCARLO.
> If you want I can send that part of the FORTRAN code from MUCARLO.
>
> Lew
>
>
> On Nov 10, 2013, at 12:33 AM, Fasso, Alberto wrote:
>
> Hi Lew,
>>
>> nice to hear from you again!
>> I am afraid that muon production by e+e- annihilation is not implemented
>> in FLUKA. Is it in MUCARLO? (I don't remember).
>> In any case, do you have any good reference to it?
>>
>> Alberto
>>
>> ________________________________________
>> From: Lewis Keller [keller_at_slac.stanford.edu]
>> Sent: Saturday, November 09, 2013 1:04 PM
>> To: Fasso, Alberto
>> Cc: Andrea.Mairani_at_mi.infn.it; "belgin pilišer"; fluka-discuss_at_fluka.org
>> Subject: Re: [fluka-discuss]: muon production frm gamma conversion or
>> positron annhilation
>>
>> Hi Alberto,
>>
>> As far as I can tell PHOTONUC only biases Bethe-Heitler production of
>> muons. How does one bias direct annihilation, e+e- => u+u- ?
>>
>> Lew Keller
>>
>> On Nov 9, 2013, at 9:50 AM, "Fasso, Alberto" <fasso_at_SLAC.Stanford.EDU>
>> wrote:
>>
>> You don't get any muons because the cross section for muon pair
>>> production is very small (about 1.E4 times smaller than that for e+e-
>>> production). You need to bias the production by a factor of that order.
>>> Set WHAT(2) = 1.E-4 in the PHOTONUC card with SDUM=MUMUPAIR.
>>>
>>> Alberto
>>> ________________________________________
>>> From: owner-fluka-discuss_at_mi.infn.it [owner-fluka-discuss_at_mi.infn.it]
>>> On Behalf Of Andrea.Mairani_at_mi.infn.it [Andrea.Mairani_at_mi.infn.it]
>>> Sent: Saturday, November 09, 2013 8:22 AM
>>> To: "belgin pilišer"
>>> Cc: fluka-discuss_at_fluka.org
>>> Subject: Re: [fluka-discuss]: muon production frm gamma conversion or
>>> positron annhilation
>>>
>>> Dear User,
>>> Can you please send us your entire input? So we can check it and in case
>>> run it..
>>> Regards,
>>> Andrea
>>>
>>> Dear Fluka Users,
>>>>
>>>> I want to produce the energy spectrum of muons from positron
>>>> annihilation
>>>> or gamma conversion by impinging the electrons to carbon target. Is it
>>>> possible?
>>>> I read that by using PHOTONUC card, MuMuPair option can switch on.
>>>> I used these cards but I didn't observe the muons.
>>>>
>>>> PHOTONUC 1111. 0.0 0.0 CARBON CARBON
>>>> 0.0MUMUPAIR
>>>> USRTRACK 1. MUONS -26. TARGET
>>>> 500.mu
>>>> USRTRACK 1500.0 500.
>>>> USRBIN 11. MUONS -21. 10.0 0.0 40.0mu
>>>> USRBIN 0.0 0.0 0.0 100.0 1.0 400. &
>>>> USRBIN 11. ENERGY -24. 10.0 0.0
>>>> 40.0edep
>>>> USRBIN 0.0 0.0 0.0 100.0 1.0 400. &
>>>>
>>>> Thanks for your advice and help from now.
>>>>
>>>>
>>>
>>>
>>
>
>



Received on Sun Nov 10 2013 - 23:16:59 CET

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