Set Flags in MC_GENERATOR.DAT

Some parameters in mc_generator.dat need to be set. In general, the flags which need to be set are the same as those for generating electrons with ES, CC, or NC interactions but some of the parameters are nullified by settings in mc_set_msw.dat.

First of all, one needs to set the interaction code to 510000. This is the code (and no other) which turns on the MSW generator. An exception has been made for the anti-CC reaction, in which the interaction code doesn't have to be 510000, this is because this reaction has three visible output particles, although in order to activate the anti-CC reaction one must ensure that the twenty-fifth flag is activated.

The position distribution can be set to anything, but to simulate reality the code 40 should be used which generates interactions in certain regions. If this is used take care to choose the correct regions. (e.g. Choose D$_2$O or H$_2$O if you want to look at elastic scattering events perhaps.) The MSW generator can currently handle the regions D$_2$O , H$_2$O , PMT ZONE, and ACRV. That is, it calculates the correct rates for CC and NC in the D$_2$O and the correct ES rates in all of the above-mentioned zones.

The direction distribution setting is nullified by choosing the interaction type in mc_set_msw.dat. For example if one is looking at CC interactions only, this flag is automatically set to 30=IDACC the proper directions for CC electrons. However one should set the parameters of the direction distribution as if one was generating CC, NC or ES interactions with the MSW generator. For example, if one wants to generate neutrinos from a fixed direction, set parameter 1=2 and parameters 2,3,4 = x,y,z respectively of that source direction. Again, to mimic reality, one should set parameter 1 = 0 which is time dependent, and will simulate the changing direction of the sun to the detector due to the earth's orbital motion (provided one chooses the correct time distribution!). As mentioned above the tenth parameter, which sets the neutrino flavor, is nullified by the setting in mc_set_msw.dat.

The energy distribution is also hard-wired by choice of interaction. So setting this will do nothing. The energy threshold parameter has been ignored since it would skew the data incorrectly. One should generate the true hypothesized spectra in full, and make cuts in the analysis only. At least that was the philosophy that was used when writing the code. Again, parameter 10 is nullified by choice of flavor in mc_set_msw.dat.

Time distribution is not hard-wired but to reflect reality one should set this to 50=IDTRATE. If this is done, the correct rates of solar neutrinos for any MSW parameters (or vacuum oscillations) will be calculated and the data will look like real data (hopefully).

As mentioned before, one must choose the start-of-data date/time. This used to be done by using the first 5 parameters but now is controlled by the JOB bank (the $INITIAL_DATE command). Parameter 6, which is the rate if running non-MSW interactions, is hard-wired into the code and setting parameter 6 has no effect. Parameter 7 is nullified by the same parameter in mc_set_msw.dat and so setting it has no effect either.

The miscellaneous distribution does not effect the MSW code.