mca Documentation

Mark Rivers

University of Chicago

mca supports Multi-Channel Analyzers (hence the name), and also related devices such as multi-channel scalers (MCS), waveform digitizers, and programmable ADCs, amplifiers and power supplies.

mca consists of:

• The mcaRecord. The mca record is device independent, and can be used to control a large number of devices in an identical way. The mca record is similar to the waveform record, in that the .VAL field is a 1-D array. However, the mca record provides many additional fields that are used to control data acquisition, regions-of-interest, etc.
• Device support for the MCA record using asyn drivers. This support is used by the Canberra, Amptek, Rontec, and fastSweep drivers in this module, as well as by the DXP driver for XIA devices in the DXP module.
• Driver support for the Canberra ICB programmable NIM modules.
• Driver support for the Amptek detectors using their DP5 digital signal processing MCAs.
• Driver support for the Rontec XFlash. This will work either with standard serial ports or with Bruker's QM100 high speed interface.
• Driver support for the SIS3801 multi-channel scaler (MCS) (formerly the STR7201 from Struck) and the SIS3820 MCS. There is support for MCS operation with either mca or waveform records, and for simple preset scaler operation with the scaler record.
• asyn fastSweep driver for waveform digitizer type devices. This is used by the ip330 module.

EPICS MCA client software.

A basic interface to the mca record is provided with medm. These screens allow one to control acquisition, view spectra on a linear or logarithmic scale. There are no markers or cursors, or tools for energy calibration or peak fitting.

mca.adl

medm mca record screen.

There is a setup window for controlling preset count times, update rates, etc.

mca_setup.adl

medm mca setup screen.

An IDL MCA display program is available, shown in the screen show below. This program is available in both a source code version that requires and IDL license to run, and also in a pre-compiled form that can be run under the IDL Virtual Machine for free. It provides tools for energy calibration and peak fitting.

IDL mcaDisplay

IDL MCA display.

Another IDL tool is provided for controlling multi-elemement detectors (MED). This screen allows one to display one spectrum at a time in the IDL MCA display tool above, and to turn off and on acquisition simultaneously on all detectors.

The IDL MCA display and multi-element display tools have also been ported to Python. With the advent of the IDL Virtual Machine that allows IDL programs to be run for free I am no longer actively working on the Python versions, but it is available.