Raymond E. Fuja

Three-Phase Energy Transfer Circuit with Superconducting Energy Storage Coils

The operation and circuit analysis of a three-phase inductor converter bridge (ICB) is described. The ICB is used to transfer energy between two superconducting coils and may find application in future tokamak fusion power reactors and large particle accelerators. This circuit provides an efficient, controllable, and reversible means for energy transfer.

The APS linac beam position monitors and electronics

Beam position monitors using stripline pickups for 30 ns long electron and positron beam bunches have been built and responses were measured in the vertical and horizontal directions. Log amplifiers used for signal processing have a dynamic range of 40 dB and are scaled for 50 mV/dB sensitivity. In this paper we describe the design of the detectors, the signal processing electronics, and the results of the position‐to‐signal mapping using a wire. Beam position measurements using a prototype detector and electronics on the APS linac test stand are discussed.

Development of microwave discharge spots in neon and helium gas by submicrosecond pulses

Microwave discharges were developed in pure neon, pure helium, and 90%‐10% neon‐helium gas around the trajectory of high‐energy charged particles by applying submicrosecond pulses shortly after the passage of the particle. The pulse width and amplitude of the discharge field were varied so that the effect on the discharge spot development could be observed. All measurements were made at room temperature and atmospheric pressure. The discharge chamber is a partially dielectric‐loaded waveguide operating in the TEM mode at 1300 MHz so that the discharge fields are uniform over the gas volume.

A uniform-field microwave discharge chamber as a high-energy particle-track device

Abstract An experimental model of a new type of high-energy particle-track illuminating device based on the microwave discharge principle has been successfully tested. The salient feature of the device is the addition of dielectric material along the waveguide walls in order to produce uniform fields over the gaseous volume. The latter represents a substantial improvement over previous models of microwave discharge chambers. Good-quality tracks were obtained with a peak rf field of 0.5 MV/m at 1300 MHz. Track quality was similar to higher-frequency discharge chambers, which clearly demonstrated that the low-frequency limit has not yet been reached. Calculations indicate that frequencies at least as low as 300 MHz should be possible. Since chamber size is inversely proportional to frequency, the low-frequency limit for good track resolution is an important consideration. Ideally, a large-volume, dense-gas device should be possible, fully exploiting the lack of average drift velocity of liberated ions by exciting the chamber in a resonant system.

Results from a Model System of Superconducting Solenoids and Phase-Shifting Bridge for Pulsed Power Studies for Proposed Tokamak EF Coils

Superconducting energy storage inductors have been proposed [1] for storing the energy of the OH and EF coils of tokamak power reactors between plasma burn cycles. Because the EF coils of a tokamak must be excited dynamically in response to plasma current, temperature, and position during the burn cycle of the reactor, unique requirements are made of the EF coil power supply system. An energy transfer circuit suggested by Peterson et al. [2] promises to meet the power transfer and control requirements of the EF coil excitation circuit supplied from a storage inductor.

Streamer chamber charging regulator system

Abstract In a streamer chamber system being built at Argonne National Laboratory, the specifications for pulse repeatability impose stringent requirements on the Marx generator charging electronics. A charging regulator using type 284 tetrode modulator tubes was developed to provide the required stability. The system philosophy, design requirements, and circuit configuration are discussed.

Power Supplies for Precooler Ring

Eight power supplies will energize the antiproton Precooler ring. there will be two series connected supplies per quadrant. These supplies will power 32 dipole and 19 quadrupole magnets. The resistance and inductance per quadrant is R = 1.4045 Ohms and L = 0.466. Each powr supply will have 12-phase series bridge rectifiers and will be energized from the 480 V 3-phase grid. The total of eight power supplies are numbered IA, IIA, IIIA, IVA, and IB, IIB, IIIB, and IVB. Each quadrant will contain one A and one B supply. A block diagram of the Precooler ring with its power supplies is shown in Figure 1.