Pulse Programmer for Electron Paramagnetic Resonance Spectroscopy

The design of a new pulse programmer is presented. It is based on an application-specific integrated circuit (ASIC) and designed to fulfill the requirements of pulse electron paramagnetic resonance (EPR). The pulse EPR ASIC provides a high time resolution (2 ns) and a high channel density (8 channels per chip). The pulse sequences are controlled by a digital signal processor (DSP). The sequence processing is solved in a general way: the pulse program, written in a high-level Pulse Programming Language (PPL), is interpreted by the DSP, which then calculates a bit image, loads it to the ASICs, and controls the sequence flow. The approach allows any sequence to be easily programmed, and the pulse EPR experiments can be carried out in real time on a repetition rate of up to 2 kHz. The new pulse programmer provides the same or even a higher time resolution and channel density than general-purpose commercial programmers, which are in use in home-built EPR spectrometers. At the same time, the device has a shorter reprogramming time than these programmers and can compete, in particular for 2D experiments, with the existing pulse EPR-oriented commercial systems. In comparison with commercial analogs the software provides the users with a more flexible control over the sequence programming. The capacity of the programmer for work is demonstrated by three-pulse ESEEM and HYSCORE experiments. © 2004 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 21B: 1–10, 2004