Maximization Of Bremsstrahlung And K-Series Production Efficiencies In Flash X-Ray Tubes

摘要: Historically, x-ray output of flash tubes was maximized empirically by changing the electrode geometry and varying capacitance pulse generator. With advent high-voltage, low-impedance transmission lines, short-duration, high-current pulses could be generated with ease. An appropriate line scaling should assure that dose maximization is not reached at expense prolongation which would reduce stop motion capability, but rather rate maximized. Additionally, anode evaporation in arc phase minimized to enhance tube life. Typically, impedance changes during discharge from infinity beginning nearly zero and, either for field emission or high-vacuum tubes, can well modeled a time-varying ohmic resistor Zx(t). Using modification Bergeron's method travelling wave analysis, transient voltage current determined out closed-form solution. This allows calculate corresponding rate-time profiles each spectrum. ideal pulsed line, charged up dc potential U0, has been assumed, characterized its characteristic Z0 time T. Three typical examples illustrate importance optimum K-series excitation on performance such as dose, maximum rate, delay width. These encompass (a) constant initially stored energy E0 = UO2T/4Z0, various combinations Zo T; (b) increasing decreasing Z0, T const; (c) parameters T, assumption Zx(t) profiles. Basic matching rules have worked order approach operation given profile. A parametric analysis revealed that, pulser impedance, there are increases bremsstrahlung radiation emissions, width also increase, thus limiting applications high-rate phenomena. detailed description results applicable an Blumlein will published elsewhere.