[en] A versatile fiber optic system of outstanding performance has been designed and utilized in the development of the CPRF pulsed power equipment. These fiber optic systems consist of a family of interchangeable, but application oriented, mother and daughter PC boards. Furthermore, a self contained, chassis, or ''CAMAC'' format of links are available. The transmitter family may be described as having a true instrumentation amplifier front end (of unique design), a temperature compensated V/F converter, and fiber optic and differential current loop outputs. The receiver family consists of various mother and daughter boards which can easily be interchanged to optimize overall system requirements. The receivers are temperature compensated and capable of driving 50Ω loads to full output. Receivers boast a better than 67 dB S+N/N ratio without any noticeable overshoot or ringing. A no input ''shutdown'' and a ''remote flag'' feature is used to protect sensitive or control hardware. The overall link performance can be typified by having a bipolar ''pick ampersand mix'' accuracy of better than .5% from all causes; offset, drift, non-linearity, and thd. Hand-picked pairs easily achieve better than .2% bipolar accuracy. A unipolar circuit can easily be set to ''0'' error, with less than .5 mV/degree C offset. Presented will be the detailed design information along with examples of application specific hardware. 11 figs., 1 tab

[en] The ZTH reversed-field pinch to be installed in the Confinement Physics Research Facility (CPRF) will produce a significant ambient magnetic field. To avoid ground-loop and other electrical problems, the diagnostics in direct or possible contact with the experiment will be accessed through a fiber optic data way. The frequency-modulated analog links developed for this system have a bandwidth of dc to 100 kHz and a signal-to-noise ratio of better than 60 dB. The fiber optic transmitter units include a signal conditioner and a microprocessor controller. The conditioners can be configured as dc-coupled, low-noise differential amplifiers, or as high-gain, low-drift differential integrators with a very long droop time constant. Magnetic field pickup is minimized by balancing sensitive circuit areas to within 5 mm² in all three planes of the PC boards. The gain, offset, and integrator reset are controlled and monitored by the microprocessor, and their status is displayed on the front panel of the transmitter unit. The signal conditioner can be controlled locally, or by way of a fiber optic coupled control network. The system allows fast, convenient, noise-immune control of a large number of signal conditioners from a central host computer. By varying the offset, the computer can verify the operational integrity of the data links. 2 refs., 6 figs

[en] The Penning Fusion eXperiment-Ions (PFX-I), part of the Innovative Concepts Initiative of the Office of Fusion Energy (OFE) is a unique magnetic confinement concept based upon the traditional nonneutral-plasma Penning trap. It is an electron/ion trap comprised of a small magnetic flux-shaper, an electron emitter, and gas supply. The trap itself has an ID of less than 40mm, with access to the center restricted through ports less than 15mm in diameter. The small trap size and relatively low electron density discounts several diagnostics. The initial diagnostic the authors are developing is based upon the Stark broadening of the Hydrogen alpha (λ=6,563angstrom) and beta (λ=4,861angstrom) lines when neutral H₂ gas is added to the electron cloud confined in the trap. For the experimental conditions (n_c ∼ 10¹⁰cm^-3), calculations indicate that ∼ 10¹³ photons/secsm-bullet cm³ should be emitted from the plasma and the H_α line should be broadened by approximately 1angstrom. In the previous experiment, PFX demonstrated super-Brillouin spherical electron focus. More recently they have trapped over 3 billion electrons in a simplified penning trap. A possible limitation is that the Q of the device may be limited by ion-ion collisions. Engineering challenges include the limited access for diagnostics and high-voltage breakdown. The advantages of this approach include a compact, cheap, simple, and incremental R and D path and range of near- and medium-term applications. Furthermore, the arbitrarily small fusion power reactor embodiment and advanced fuel operation possibilities are excellent

[en] A bolometer system for measuring energy flux in a noisy electromagnetic environment is described. The system consists of a platinum foil grid, heated by energy flux from a fusion plasma experiment, whose resistance controls the frequency of a 5-MHz oscillator. The information about heating of the foil is thus shifted to a high-frequency band, and noise pickup (which is mainly at lower frequencies) is reduced

[en] A bolometry system for time and spatially resolved energy-loss measurements on the ZT-40M reversed-field pinch is described. This system allows ∼100-μs time resolution with a radiation detection limit of ∼100 mW/cm² , in particularly noisy electromagnetic environments. The bolometer element fabrication using evaporative techniques and photolithography is discussed. Increased noise rejection is realized by using an oscillator/FM receiver electronics system based on 5-MHz ac excitation of the resistor. An improved oscillator is described. Because resistive sensing is done at 5 MHz, pulsed heating currents may simultaneously be passed through the bolometer resistor and this allows for absolute in situ system calibration. We describe a new method of such calibration that is independent of the resistor geometry