X Ray Emission From The Interaction Of A Macroscopic Particle With A Dense Plasma Focus

Recently the interest in dense plasma focus has greatly increased because of the possibility of developing the device into an intense, pulsed radiation source of X-rays and neutrons for test purposes. Various experimenters have tried to scale up their radiation intensities by using large capacitor banks. Yet experimental results show that besides the engineering problems associated with the machine as the bank voltage or capacitance goes up, the intensity cannot be scaled up indefinitely by increasing the bank energy. This work proposed a new, alternative way to enhance the X-ray radiation by using a macroscopic particle to interact with a plasma focus. A theoretical study was carried out to predict the relative amount of X-ray increase when a macroscopic particle was placed in the focus region. Two assumptions were made in this study: the particle essentially had the same physical dimensions throughout the lifetime of the focus because of enormous hydrodynamic pressure compressing any ablated neutral cloud onto the particle; and the electrons were thermalized to assume a Maxwellian distribution. Most of the X-ray radiation from a focus was due to the electron bombardment of the anode surface and was accounted for by the thick-target Bremsstrahlung theory. According to this theory, the X-ray emission was proportional to the first power of the atomic number, Z, of the target material, but not to the square of Z as in the thermal Bremsstrahlung case.