It is currently Thu Jun 20, 2024 11:02 pm

 All times are UTC - 8 hours [ DST ]

 Page 1 of 1 [ 7 posts ]
 Print view Previous topic | Next topic
Author Message
 Post subject: question of CR nuclei injection functionPosted: Wed Sep 09, 2015 11:05 am

Joined: Mon May 28, 2012 7:38 pm
Posts: 20
Dear all,
I want to understand the injection function of heavier nuclei.

In 5.5.1 of the manual,
in normalization of the nucleon primary source function,
the source abundance of heavier nuclei is
X = Q_A/Q_1 = A*C_A/C_1 ...,
C_A/C_1 = X*A^(gamma-1)*Z^gamma
Why there is one more A here ?
If it is like this: q_A(p_A) dp_A = q_A(p_A) *dp_A/dEk_n *dEk_n,
where Ek_n is the kinetic energy per nucleon, and dp_A/dEk_n = A/beta
Then in flux I(Ek) = c/4pi *n *A, and at last both of A are cancelled actually.

And for the corresponding secondary particle, there is one more A is formula 13
for secondary positron.
And for secondary electron and antiproton. Maybe A_j ?
But in secondary nuclei, there is no A, for example formula 20.
Because it is the integral in p_A space?
Here I have a question.
In some literature, people assumed hard sphere approximation, i.e. before
and after spalltion, kinetic energy per nucleon is conserved.
But here in 19 and 20, it seems that you don't use that assumption. Right?
How large is the difference between both two?

Thank you very much for your reply!

Wei

Top

 Post subject: Re: question of CR nuclei injection functionPosted: Wed Sep 09, 2015 11:38 pm

Joined: Wed May 17, 2006 7:02 am
Posts: 285
Location: MPE Garching
Thanks for your questions, I will prepare a reply. Such comments are very useful!

_________________
Andy Strong, MPE

Top

 Post subject: Re: question of CR nuclei injection functionPosted: Thu Sep 10, 2015 7:05 am

Joined: Mon May 28, 2012 7:38 pm
Posts: 20
I read manual again, I find in spallation,
galprop still applies hard sphere scattering approximation.
but just in momentum space.

Top

 Post subject: Re: question of CR nuclei injection functionPosted: Thu Sep 10, 2015 7:33 am

Joined: Wed May 17, 2006 7:02 am
Posts: 285
Location: MPE Garching
yes it does that approximation. The grid is aligned on kinetic energy per nucleon for this reason, although the propagation is done in momentum. So that is correct.

_________________
Andy Strong, MPE

Top

 Post subject: Re: question of CR nuclei injection functionPosted: Thu Sep 10, 2015 7:51 pm

Joined: Mon May 28, 2012 7:38 pm
Posts: 20
thank you very much for getting back to me!

Top

 Post subject: Re: question of CR nuclei injection functionPosted: Thu Sep 10, 2015 10:24 pm

Joined: Mon May 28, 2012 7:38 pm
Posts: 20
in decayed cross section,
when spallation, rather decay,
is branching_ratio = 1？
what is its vlaue?
or it has value when decay appear?

thank you very much !

Top

 Post subject: Re: question of CR nuclei injection functionPosted: Fri Sep 11, 2015 5:21 am

Joined: Wed May 17, 2006 7:02 am
Posts: 285
Location: MPE Garching
re: X = Q_A/Q_1 = A*C_A/C_1 ...,
this is from (8) since p' = p_A /A
Q_A(p')dp'=q_A(p_A)dp_A
Q_A(p')=q_A(p_A)dp_A/dp'=Aq_A(p_A)
The algebra seems correct.

The relation p' = p_A /A should be written explicitly, I will do that in the next version.

For the fragmentation the sitiuation is similar, going from 'per nucleon' to 'per nucleus'.

I agree the formulation is confusing, and should be clarified, and checked too (comments like yours help!).
We need to think more carefully about how abundances are defined in fact.

_________________
Andy Strong, MPE

Top

 Display posts from previous: All posts1 day7 days2 weeks1 month3 months6 months1 year Sort by AuthorPost timeSubject AscendingDescending
 Page 1 of 1 [ 7 posts ]

 All times are UTC - 8 hours [ DST ]

Who is online

Users browsing this forum: No registered users and 1 guest

 You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot post attachments in this forum

Search for:
 Jump to:  Select a forum ------------------ general astrophysics    cosmic rays    gamma rays    interstellar medium    heliospheric modulation    cosmic-ray data galprop general discussion    galprop applications    galprop compilation    galprop debugging    galprop tests    galprop developer    galprop website    galprop features    galprop help    galprop WebRun    2011 GALPROP Workshop: abstracts and discussion other codes    analytical models    semi-analytical models    numerical models    comparisons with galprop    heliospheric modulation