NBS/Los Alamos RTM. Progress report

The NBS-Los Alamos 200 MeV Racetrack Microtron (RTM) is being built under a program aimed at developing the technology needed for high-current intermediate-energy CW electron accelerators. In this report we give an overview of the present status of the project. Recent progress includes: (1) completion of testing of the 100 keV chopper-buncher system demonstrating a normalized emittance well under the design goal of 2.6 ..pi.. mm mrad at currents exceedings the design goal of 600 ..mu..A; (2) operation of the rf structures comprising the 5 MeV injector linac at power levels up to 50 kW/m, resulting in an accelerating gradient at ..beta.. = 1 of 2 MV/m (compared to a design goal of 1.5 MV/m). The measured shunt impedance is 82.5 M..cap omega../m; (3) construction and installation of the 30 ton end magnets of the RTM. Field mapping of one magnet has been completed and its uniformity exceeds the design goal of +-2 parts in 10/sup 4/; (4) performance tests (with beam) of prototype rf beam monitors which measure current, relative phase, and beam position in both transverse plants; and (5) installation and initial operation of the primary control system.