The very intense pulse of X-rays required for hydrodynamics experiments is achieved by charging a metal cathode to a potential of millions of volts, and discharging tens of thousands of amps of electrons across a vacuum gap.
The electrons are focused into a small region by magnetic forces. The deceleration of the electrons as they collide with the tantalum target anode liberates Bremsstrahlung X-rays.
It is important to optimise the output of the X-ray machines, i.e. to maximise the X-ray dose and minimise the diameter of the target area from which X-rays are produced. Particle in Cell codes can be used to help achieve this (Figure 1). |
Figure 1. |
AWE is actively developing state of the art pulsed power machines and intense electron beam diodes to deliver the next generation flash X-ray sources. Plasma spectroscopy and interferometry are being employed to help to understand the plasma dynamics of the radiographic diodes.
Specialist detector systems are required to efficiently record high resolution images of penetrating high energy X-rays. Photon energies in the range of several MeV are recorded with spatial resolution of less than 1mm. Currently phosphor image plates are the primary X-ray detectors used, however work is underway to develop X-ray scintillators and opto-electronic camera systems (Figure 2). |
Figure 2. |
