Current version – WimpSimp 1.2

Compared to version 1.12 below, this version has a few added functions:

Apart from generating muons at the neutrino-nucleon vertex, event files with the neutrinos directly can also be generated. Notice, that the neutrinos generated are the sum of nu_mu and anti-nu_mu.
To improve simulation statistics, there is now also a possibility to use a weight function on the distribution. This means that if e.g. the neutrino flux distribution is d^2N_nu/dE dtheta, one can choose to instead generate events according to the distribution d^2N_nu/dE dtheta * f_weight, where f_weight is the weight function. Possible choices are

f_weight = 1, i.e. no weight

f_weight = E, i.e. generate more events with higher energy. If neutrino-fluxes are used, the resulting muon events will show a similar distribution in energy as if muons are generated directly with a weight of 1. The reason for this is that when the neutrinos interact they will generate muons with lower energy, but the cross section rises as E and hence energy loss is compensated for by the cross section. With the weight E on the neutrino distribution, the resulting muon distribution will thus be similar to the muon distribution with a weight of 1.

f_weight = E^2, i.e. generate even more events with higher energy. This could be useful if you want to have higher statistics at higher energies.

Note, that the weight functions refer to the distribution functions. In the output file, the individual events will have an additinal column with weight factor 1/weight to include the fact that the higher energy events should have a lower weight since they are over-abundant in the files. All weights are normalized to the fluxes/distributions at 1 GeV. I will update my conversion scripts to allow for these wieghts there as well when converting between different fluxes/rates.
To allow for weights, the format of the output wf-files has now changed. The version number of the output format is now WF 1.1. The new files look like this:
```
     
#WF 1.1
#Creator: WimpSimp 1.2   (version from March 18, 2003      )
#Parameters:  mneu=   250.00 where=su channel= 5 nevent=   10000 wtype= 1
#Date:   3- 4-25
EVENT        1
nu      0.000000E+00 0.128389E+03 0.262861E+02 0.380429E-01
EE
EVENT        2
nu      0.000000E+00 0.159240E+03 0.771310E+02 0.129650E-01
EE
    
```
First there is a header telling the version of the wf-file and some simulation details. Then the events come, each event starts with EVENT and the event number. The tracks then follow, in this case only one track per event. The first information in the track record is the particle type (nu or mu), then the theta-angle (in degrees), the azimuthal angle phi (in degrees), the energy (in GeV) and finally the weight (relative to the events at 1 GeV). Each event ends with EE.
The old HEMAS-like output format is taken away since it wouldn't support weights (and is not used anymore either).

Below you will find a gzipped tar file with WimpSimp 1.2. Download it, unpack it and follow the instructions in the README file. If you have questions, send me an e-mail. If you use these routines, please quote that you got them from me and refer to the most recent publication where they are mentioned, L. Bergström, J. Edsjö and P. Gondolo, Phys. Rev. D58 (1998) 103519. In that publication you will also find more details about how the simulations behind these routines were performed.

Click here to download wimpsimp-1.2-030318.tar.gz.

The next step is to convert the wf files to f2000 files. This is done by wf2f2000.

Older versions – WimpSimp 1.12

Below you will find a gzipped tar file with WimpSimp 1.12. Download it, unpack it and follow the instructions in the README file. If you have questions, send me an e-mail. If you use these routines, please quote that you got them from me and refer to the most recent publication where they are mentioned, L. Bergström, J. Edsjö and P. Gondolo, Phys. Rev. D58 (1998) 103519. In that publication you will also find more details about how the simulations behind these routines were performed.

Click here to download wimpsimp-1.12.tar.gz.

Up one level.

Joakim Edsjö, edsjo@fysik.su.se. This page was last updated 2003-06-12 .