String trigger simulation

The string trigger is now included in amasim. I used the program treval by Thomas Feser to check that it works as expected. Treval was earlier the only way of simulating the string trigger. To do this you had to run amasim with low threshold and then run treval to evaluate what triggers the events would have got if a combination of string and multiplicity triggers had been used. This method could be used to check how many events would be triggered with different trigger settings, but it does not give the right time distribution in the events. Including string trigger directly in the simulation of the detector response is a better way.

I made a quick check on the correlation between what triggers amasim sees and what treval gives. This was made on a sample of WIMP Monte Carlo. The result is shown in the table below. "string" means string trigger, "comb" means that string and multiplicity triggers were present. The columns are amasim triggers, the rows treval triggers. All percentages are relative to the number of events triggered by amasim with that trigger.

The trigger settings in amasim were: multiplicity of 24 and string correlation 7/11 and 6/9 (on the innermost four).

Clearly the amasim triggers work as they should.

amasim string amasim mult amasim comb

treval string 93% 0% ~0%

treval mult 0% 97% ~0%

treval comb 5.5% 1.6% 99.6%

Anna Davour 2002-08-07

	amasim string	amasim mult	amasim comb
treval string	93%	0%	~0%
treval mult	0%	97%	~0%
treval comb	5.5%	1.6%	99.6%