sntools

sntools is a Monte Carlo event generator for supernova neutrino interactions.

Based on detailed time- and energy-dependent neutrino fluxes provided by various supernova models, it generates interactions within the detector volume and writes them to event files that can be used as an input for a full detector simulation. sntools was originally developed for Hyper-Kamiokande and later extended to support different detectors and detector materials.

Getting Started

First, make sure you have Python installed on your computer. (Either Python 2.7 or Python 3.x is fine.)

Then, in a terminal, run

pip install sntools

to install the latest version of sntools and all dependencies. (sntools currently requires numpy 1.8 (or higher) and scipy 0.17 (or higher).)

You can then run

sntools -h

for a brief summary of all of sntools’ options. A typical usage will look something like this:

sntools fluxes/intp2001.data --format nakazato --ordering normal --detector HyperK

This generates events for a supernova in Hyper-Kamiokande, assuming normal mass ordering and the neutrino flux given in the input file fluxes/intp2001.data, which is in the nakazato format. (That sample file is included in the sntools repository. See this web page for more information.)

Input

Text file(s) containing information about neutrino fluxes produced by the supernova. sntools distinguishes between three flavours: nu_e, anti-nu_e and nu_x (where nu_x stands for nu_mu or nu_tau or their respective antineutrinos). The following input formats are supported; see the source files in the formats/ directory for details.

Nakazato format

Used by recent simulations by the Nakazato group. Fluxes for 13 and 20 solar mass progenitors are included as fluxes/intp1301.data and fluxes/intp2001.data. A description of the format and fluxes for more progenitors are available online. If you use these included models in your work, please cite Nakazato et al., ApJ Supp. 205 (2013) 2.

Gamma format

Text file containing time, mean energy, mean squared energy and luminosity. These parameters describe a Gamma distribution, which is a good fit to the true spectrum. See fluxes/sample-gamma.txt for an unphysical sample file.

Princeton format

Used in recent simulations by the Princeton group.

Totani format

Used in historical simulation by Totani et al., which is the baseline model in the Hyper-Kamiokande Design Report.

Interaction Channels

sntools supports the main interaction channels in water and liquid scintillator.

For water Cherenkov detectors, like Hyper-Kamiokande, these are inverse beta decay, elastic scattering on electrons and charged-current interactions of nu_e and anti-nu_e on oxygen-16 nuclei.

For liquid scintillator detectors, these are inverse beta decay, elastic scattering on electrons, charged-current interactions of nu_e and anti-nu_e on carbon-12 nuclei and neutral-current interactions on carbon-12 nuclei.

Water-based liquid scintillator, a mixture of the two materials, is also supported.

For details, see the files in interaction_channels/.

Output

A .kin file in the NUANCE format used by the /mygen/vecfile options in WCSim. See the format documentation for details.