A method of expanding the 1700 MeV, 100 mA proton beam of the APT linear accelerator onto the 19 by 190 cm target has been devised using eight ferrite dipole magnets. These magnets deflect the beam in the x and y-plane, and thereby paint the target area uniformly with a rastered pattern. Insulated Gate Bipolar Transistor (IGBT)-based power modulators drive the raster magnets with triangular current waveforms that are synchronized using voltage controlled crystal oscillators and phase-locked loops (PLLs). Redundant fault detection circuits monitor both the ac magnet currents and magnetic fields to ensure proper operation. This paper presents the test results taken on an integrated prototype system including eight magnets, the associated modulators, the master clock and the fault detection circuitry. BACKGROUNDA raster-type beam expander system, originally described in Ref. [1,2], has been built and the integrated system has been tested. The full prototype system allows evaluation of several aspects of the system-level operation which include interactions between the eight magnets and their power modulators and the ability of the fault detection circuitry to independently detect problems with the raster system. Fig. 1 shows the raster magnets as they fit into the high energy beam transport (HEBT) portion of the APT Linac. SYSTEM DESCRIPTIONThe block diagram of the Raster Magnet System shown in Fig. 2 consists of the 1) IGBT modulator, 2) master clock, 3) raster magnet and 4) fault detection circuitry. IGBT ModulatorThe IGBT modulator consists of an ac/dc converter, a capacitor bank, and an IGBT H-bridge with a gate driver board. The modulator circuit is shown schematically in Fig. 3. Each modulator is powered by uninterruptible _______________________ *Work supported by DOE contract DE-AC04-96AL89607 # e-mail: martin.schulze@gat.com The dc capacitor bank exchanges reactive power with the magnet on a 1 kHz time scale (twice per cycle). The IGBT H-bridge controls the transfer of charge back and forth between the capacitor bank and the magnet. The diodes across each switch, referred to as freewheel diodes, recover the stored magnetic energy.
EML bnrrel kngthPreacceleraior barrel Ien.eL 425 3 m ImAbstract -A small-bore hypervelocity Electromagnetic Imincher laboratory research facility has been developed which has launched a 2-g projectile to it velocity in excess of 3.5 knilsec. This turn-key laboratory includes a 1 cm, square bore railgun with a helium gas preaccelerator; a modular 328 kJ capacitor bank; a fiber-optically linked PIX-based control system with a graphical operator interface; it CAMAC-based diih acquisition system with current, magnetic, and prqjectile position diagnostics; and a flight range which provides in-flight velocity measurements and safely stops and contains the prqjectile. The control system is designed to fire the preaccelerator and upon receipt of an optical trigger signal, fire the capacitor bank modules simiiltaneoiisly or in a staggered mode.During initial testing at GA, armature separation and ~ti~lling were observed which limited the overall performance of the system. Changes in pulse S h i I I X and bore iIli1teriitls significantly improved the performance of the system. This paper includes a discussion of the system, methods used to minimize armature separation and improve performance, and test results.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.