Two methods of using the X pinch as a source of X-ray radiation for the radiography of dense plasmas and other objects
are presented. These methods do not use pinholes, instead taking advantage of the small source size (<1 mm, and in some
cases <1 pm) and short X-ray emission duration (< 2 ns , and < 20 ps in some cases) of the X pinch radiation. Detailed
measurements of the emission characteristics of X pinches made using different wire materials and in different energy
ranges using a set of X-ray diagnostics with high temporal and spatial resolution are presented. Several applications of
the X pinch are discussed.
The X pinch plasma emits subnanosecond bursts of x-rays in the 3 - 10 keV energy range from a very small source. As such, it has been used for high-resolution point-projection imaging of small, dense, rapidly changing plasmas, as well as submillimeter thick biological samples. The very small x-ray source size of the X pinch provides high spatial coherence of the x-rays, enabling the X pinch to be used for imaging low absorption, low contrast objects with excellent spatial resolution by incorporating wave-optics effects. The reverse procedure has been used to determine the X pinch x-ray source size: well-defined micro-fabricated slits were imaged by point-projection radiography, and the detailed patterns were compared with wave-optics calculations of the expected image patterns on film as a function of x-ray source size and energy band. In addition, an x-ray streak camera was used to study the X pinch source size as a function of time. Dynamic shadow images of a boron fiber with a tungsten core and glass fiber sheathed in plastic were compared with a time-integrated radiographic image. Source sizes as small as 1.2 μm (full width at half maximum, assuming a Gaussian spatial intensity profile for the source) have been inferred.
X pinch radiation produced by electron beams accelerated in the X pinch minidiode ranging in energy from 10 to 100 keV has been studied and used to image a variety of different objects. The experiments have been carried out using the XP pulser (470 kA, 100 ns) at Cornell University and the BIN pulser (280 kA, 120 ns) at the P.N. Lebedev Physical Institute. This electron-beam-generated x-ray source's geometric, temporal and spectral properties have been studied over different energy ranges between 10 and 100 keV. The imaging was carried out in a low magnification scheme, and spatial resolution of a few tens of μm was demonstrated.