[Mesa-users] Formicola 2004 reaction rate
meisel at ohio.edu
Sun Oct 15 19:19:14 EDT 2017
One of the best online references I can think of for this would be Hendrik Schatz’s nuclear astrophysics lecture notes. For the s-factor, this lecture should be useful: https://people.nscl.msu.edu/~schatz/PHY983_13/Lectures/rates_direct.pdf
Asst. Prof. of Physics & Astronomy
Email: meisel at ohio.edu
From: Earl Bellinger<mailto:bellinger at mps.mpg.de>
Sent: Sunday, October 15, 2017 9:32 AM
To: Francis Timmes<mailto:fxt44 at mac.com>
Cc: mesa-users<mailto:mesa-users at lists.mesastar.org>
Subject: Re: [Mesa-users] Formicola 2004 reaction rate
Thanks Josiah and Francis for your useful replies. I've run through
the inlists and now can get all that to work.
I am still running into some difficulties however putting this into
practice in the context of the Formicola result. The update to this
rate comes in the form of the astrophysical s-factor. In other
evolution codes (e.g. YREC) it is possible to alter s-factors
individually. In an earlier mesa-users thread  however, Rob Farmer
explains that the s-factors cannot be altered directly in MESA;
instead, new reaction rates must be computed with the new s-factor. Is
that still the case? If so, does anyone have any advice as to how I
can calculate the rates manually with this different s-factor, so that
I may then insert them using the procedures described above?
Thanks again for any assistance.
Earl Bellinger, Ph.D. Candidate
SAGE Group, Max Planck Institute for Solar System Research
Department of Astronomy, Yale University
On Fri, Sep 29, 2017 at 7:56 AM, Francis Timmes <fxt44 at mac.com> wrote:
> hi earl,
> 1) unzip the attached rate_tables.zip file.
> 2) place the "rate_tables" folder in your mesa work directory.
> 3) inspect the contents of "rate_tables" :
> "rate_list.txt" holds the (rate name, rate file) pair for strong and e&m rates.
> in this example, it is set to use (r_c12_ag_o16, new_c12_ag_adopted.txt) pair,
> so the c12(a,g) will be replaced by whatever is in "new_c12_ag_adopted.txt".
> "weak_rate_list.txt" holds the (rate name, rate file) pair for weak reactions.
> in this example, it is empty.
> "new_c12_ag_adopted.txt" holds the (T8,rate) pairs to be interpolated and tabularized.
> in this example, its a rendition of the new deboer et al 2017 c12(a,g) rate.
> 4) in the &star_job part of your inlist activate the custom rate with
> ! set any specific reaction rates
> rate_tables_dir = './rate_tables'
> hopefully (a) i haven't forgotten anything and (b) you can morph this into whatever rate(s) one wants.
> > On Sep 28, 2017, at 11:06 AM, Josiah Schwab via Mesa-users <mesa-users at lists.mesastar.org> wrote:
> > Hi Earl,
> > Sorry for the extremely brief reply. (Maybe more later.)
> >> As far as I understand it, the default nuclear reaction rates in MESA
> >> are the NACRE rates from Angulo et al. 1999 .
> >> In 2004, Formicola et al.  provided an update to the 14 N(p, γ) 15
> >> O reaction.
> >> Is this rate in MESA at present, perhaps with a hook to toggle it?
> > No. But MESA has JINA reaclib v2.2, where the default is
> > https://groups.nscl.msu.edu/jina/reaclib/db/n14(p,g)o15/im05/
> > from G. Imbriani et al. (2005).
> > I would guess those are quite similar since Imbriani was 2nd author of
> > Formicola, but I don't know.
> >> Some grepping around indicates that the answer is 'probably not,' and
> >> so short of that, has anyone implemented it already for their own use
> >> and would be kind enough to share it?
> >> If not, I can implement it myself. I have a rough idea how to do it,
> >> although having never waded here before, suggestions for how to do it
> >> would also be appreciated :-)
> > Take a look at the test_case custom rates for an example.
> > Josiah
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