A Java-based data acquisition system for nuclear physics

Jam is a Java-based user-friendly data acquisition and analysis system developed for CAMAC-based nuclear physics experiments. The system is menu-driven and has been designed to minimize the expertise needed to perform the essential tasks necessary to collect and sort data. The front-end hardware is VME based and includes a MVME167 running VxWorks, which is networked to a Sun workstation. The sorting, display, and control routines are all written in Java, and the front-end code is written in C. With a Sparc 5 workstation, events with 10 parameters, 15 histograms, and 10 gate checks the system can collect and sort data up to event rates of 1 kHz. By only sorting a fraction of the events, but storing all events, it can be run at the front-end limit of 10 kHz. Javaʹs promise of platform independence has been found to be realistic, and Jam has been used with no modifications to sort offline on multiple platforms. Jam has a modular design allowing it to be easily modified. For example, Jam has an interface to allow users to write their own fitting routines. This article discusses the systemʹs design and performance, as well as some advantages and disadvantages of using Java.