6533b857fe1ef96bd12b3922

RESEARCH PRODUCT

Present state of the MAMI control system

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description

Abstract MAMI (Mainz Microtron) is an electron accelerator consisting of a cascade of three race-track microtrons, with an output electron beam of 855 MeV and 100 μA cw [1]. The first two stages (output energy 180 MeV) were operative for nuclear-physics experiments from 1983 to 1987 and have since been transferred to a new building. They will serve as an injector for the third stage, now under construction. The control system for MAMI was based on a versatile process communication software system for a network of processors with multiprocess operating systems. This system has previously proved very successful, so we decided to rely on it as control system for the new, upgraded accelerator, replacing the control computers (instead of two HP1000s, now one MicroVAX-II) and making several changes and extensions. We strictly unified the communication interface to the processes. Accordingly, a set of display, steering, measuring and optimization processes can be used in a flexible manner: for example, emittance measurements at several points of the beam line and automatic beam-position optimization in the beam line and in the microtrons. Using a portable compiler generator, we were able to develop a BASIC-like interpreter for high-level control purposes in a very short time (one man-month). In addition to the MicroVAX we are planning to operate other processors as well (VME and single-board computers), coupled via Ethernet, using our communication software.