The Use of Arrays Smaller than Implied by the Range of Descriptors for Multiparameter Pulse Height Analysis

A program for use with multiparameter pulse height analysis is described. The main purpose of the program is to permit reasonably rapid accumulation of data into arrays which are much smaller than implied by the range of descriptors. In addition the method readily permits the use of descriptors which exceed the bit capacity of the computer word. Any grouping of zero and non-zero channels as is observed in most real spectra is especially exploited. In many cases, the data can be retained in a packed array in core memory until the actual number of non-zero channels becomes almost as large as the allotted core-memory space, at which time the array is transferred to another space in core (where it will be transferred onto disc as a background operation), the core array is reinitialized, and the data acquisition is continued. With this procedure, multichannel arrays as large as the available disc memory can be stored on disc without the data acquisition suffering from the very slow random access time of the disc. Methods of data handling and the resulting effective counting rates are discussed.