Nuclear engineering

Permanent URI for this collectionhttps://digital.lib.washington.edu/handle/1773/4947

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    Measurement of the internal toroidal magnetic field on the helicity injected tokamak using the transient internal probe
    (1996) Galambos, James Paul
    The Transient Internal Probe is a novel diagnostic technique specifically developed to measure internal magnetic field profiles in hot plasmas. The concept involves shooting a magneto-optic probe through a plasma at high velocity so that field measurements are obtained before ablation of the probe begins. The magnetic field profiles are obtained by illuminating the probe with a linearly polarized laser and measuring the amount of Faraday rotation induced in the beam as it passes through the probe and is reflected back to the detection system. Coupling between the gas gun and the high vacuum regime of the plasma chamber is achieved with a highly efficient gas interface system such that less than 0.4 torr-I (0.003%) of the muzzle gas enters the plasma chamber. Determination of the polarization angle of the reflected light is accomplished with a high speed, high resolution polarimeter.The TIP concept was demonstrated by measuring the internal toroidal magnetic field profile on the Helicity Injected Tokamak. Measurements were conducted with the probe traveling more than 1.9 km/s. Field measurement accuracy was better than 2.5% with spatial resolution of better than 1 centimeter. Qualitative results concerning the time required for ablation of the probe to begin were obtained and these results supported the surface boiling model used to predict probe behavior. These results proved the diagnostic to be a valuable new tool for investigating the magnetic structure of hot plasmas.
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    The conceptual design of a Mars nuclear landing and ascent vehicle utilizing indigenous propellant
    (1992) Zubrin, Robert M
    Interplanetary travel and exploration can be greatly facilitated if indigenous propellants can be used in place of those transported from Earth. Nuclear thermal rockets offer significant promise in this regard, as in principle, any gas at all can be made to perform as a propellant to some extent.In particular, the Martian atmosphere is composed of 95% CO$\sb2$. Under Martian conditions, this gas can be liquified by simple compression to about 100 psi, and remains storable without refrigeration. When heated to 2400 K and exhausted out of a rocket nozzle, a specific impulse of about 226 s can be achieved. This is sufficient for flights from the surface to orbit or from one point on the Martian surface to any other point on the planet. Because the power requirements for acquiring CO$\sb2$ are quite low, the propellant acquisition system can travel with the vehicle, allowing it to refuel itself each time it lands. Thus this vehicle concept, which is termed a NAV (Nuclear Ascent Vehicle), offers unequalled potential to achieve planetwide mobility, allowing complete global access for the exploration of Mars, and potentially can reduce the initial mission mass in LEO as well.This dissertation presents the results of an extensive study which centered on the conceptual design of a NAV vehicle with surface to orbit capability. Carbon dioxide was the propellant of choice, with some examination of alternate concepts using other propellants. The NAV configuration defined by the conceptual design was used as a basis for defining engine performance requirements, and a detailed study of a potential NAV engine that could meet these requirements was then conducted. The resulting NAV/engine combination was then examined in a series of trade studies to determine its potential merit in assisting in the exploration of Mars.