noise模块

手册里提供了一个noise模块：

/gate/distributions/name energy_distrib
/gate/distributions/insert Gaussian
/gate/distributions/energy_distrib/setMean 140 keV
/gate/distributions/energy_distrib/setSigma 1 keV
/gate/distributions/name dt_distrib
/gate/distributions/insert Exponential
/gate/distributions/dt_distrib/setLambda 7.57 mus
/gate/digitizer/Singles/insert noise
/gate/digitizer/Singles/noise/setDeltaTDistribution dt_distrib
/gate/digitizer/Singles/noise/setEnergyDistribution energy_distrib

加上这个模块以后，总的计数居然减少了（其他条件完全一样）。