Dear Tom.
On 9 Jun 2011, at 20:55, Tom Roberts <[log in to unmask]> wrote:
> Costas:
>
> Thank you. That sounds simple enough.
>
> I believe that after changing config/UserPhysicsOptions.xml I must re-generate all of the splines. But the posted gxspl-freenuc-v2.6.2.xml only goes up to 200 GeV. So how do I generate the free nucleon splines? Do I just do this:
> unset GSPLOAD
> gmkspl -p 12,14,16,-12,-14,-16 -t 1000000010,1000010010 -e 2000 \
> -o freenuc-v.2.6.2.xml
> and then set GSPLOAD=$PWD/freenuc-v.2.6.2.xml for the other targets?
Yes.
Generating the free nucleon splines takes long time (integrating the differential cross section for every modelled process -about 100 or so- for every energy for every initial state).
What I do is to split the task and submit multiple jobs at a batch farm. Then I combine the XML outputs using the gspladd utility (see manual).
See in src/scripts/production/batch (or in http://projects.hepforge.org/genie/trac/browser/trunk/src/scripts/production/batch ). The script you want is named submit-xsec_freenuc.pl .
I am using it at the RAL/PPD Tier2 which is using PBS. But the script also supports LSF so you should be able to adjust it easily and use it at FNAL.
With the gmkspl utility you can use the "-n" option to set the number of knots in each spline. By default gmkspl uses logarithmically spaced knots, starting from the energy threshold of each process. It uses (by default) 15 knots per decade. Use a sensible number to avoid getting an enormous XML file, especially if you plan to add multiple nuclear targets.
cheers
Costas
--
Dr Constantinos Andreopoulos
Staff Scientist
STFC, Rutherford Appleton Lab
http://costas.andreopoulos.eu
Sent from my iPhone
>
>
> Note I will be running Genie for the neutrinos from 2 TeV muon decays, so different neutrino types and energies are all mixed together. (I am interfacing Genie to another simulation program that handles everything except the neutrino interactions, tracking neutrinos with greatly enhanced interaction lengths in regions of interest.)
>
>
> Tom Roberts
>
>
> On 6/9/11 6/9/11 - 1:23 PM, Costas Andreopoulos wrote:
>> Just increase in the limit at the very end of the config/UserPhysicsOptions.xml .
>> I do not think that the simulation quality deteriorates very fast in high energies.
>> Results at ~2 TeV should be sensible. But, I've never run the simulation at 2 TeV.
>> Let me know if there are problems.
>>
>> You don't have to use the --enable-vhe-extension. This is experimental and,
>> currently, it just adds a Glashow resonance generator (PeV scales).
>> This option should (but it currently doesn't) adjust the DIS generator for use in higher-energies
>> (use a lower minimum Bjorken x cutoff value, use a PDF set other than the Bodek-Yang which is tuned
>> to high-x low-Q2 data, switch-on the propagator term in the DIS cross section etc... ).
>>
>> Also if you are running GENIE at 2 TeV then (for reasons of computational efficiency)
>> you may want to disable all modes other than DIS.
>>
>> Best,
>> Costas
>>
>> On 8 Jun 2011, at 22:13, Tom Roberts wrote:
>>
>>> I want to investigate neutrino backgrounds from a muon collider, so I need neutrino energies up to about 2 TeV.
>>>
>>> What is the status of Genie's very high energy extension? How do I use it?
>>>
>>> In my .configure command I included --enable-vhe-extension. But in gmkspl when I try to go above 300 GeV it says "Refusing to exceed validity range: Emax = 300".
>>>
>>> As I am investigating backgrounds, I am primarily concerned with the total cross-section, and not the details of the secondaries (as long as they are not crazy). I realize there are no experimental data at such high energies, and there are theoretical uncertainties.
>>>
>>> Is there anything simple I can do that will give results up to 2 TeV that aren't crazy (even if they are not known to be accurate)?
>>>
>>>
>>> Tom Roberts
>>
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