Design an Experiment to Identify Characteristic X-ray Spectrum Emitted by Xe Ion in Fast Mixed Heavy Ions

Abstract

There are a lot of particles in space, including protons and heavy ions mainly. These particles in space can induce different radiation effects on the electronic devices, such as single event effect and displacement damage. The single event effect is the main reason of the abnormal function in spacecraft. Astronautical electronic devices have to be tested in similar radiation environment before applied in spacecraft. However, it is difficult to test all devices in space or to create a space-like radiation environment. As a result, the experiments on the ground have mainly relied on the tandem accelerator and the cyclotron accelerator. The cyclotron accelerators usually use an ECR ion source for injection, which mean that ion species are more complex than the tandem accelerators. It makes identification difficult by mass spectrometer because the ECR ion source injected different ions with the similar charge-mass ratio into the cyclotron accelerator at the same time. We need to find a new way to distinguish the ions with similar charge-mass ratio in the cyclotron accelerators. There are some studies about the collisions between fast heavy ions and atom targets. When the fast highly charge ion collided with atom targets, they both will emit the characteristic X-ray due to the electron transitions in different shells. Thus it is possible to identify the ions by their different characteristic X-ray spectra. An experiment design was carried out to identify Xe using this technique by these considerations, including the Xe cross section by different atom targets, the characteristic X-ray energy, the photo detectors, and other factors. Firstly, Ag and Mo were chosen as atom targets according to previous experimental data on the X-ray yield of Xe colliding with different atoms. Secondly, the HPGe detector was chosen to detect the X-ray according to the comparison of the characteristic X-ray of Xe, Ag and Mo, and the energy resolution required better than 10 keV. Thirdly, the angle of detecting X-ray would affect the X-ray energy gently. Another the Mylar/Kapton film will degenerate the X-ray intensity similarly, the Mylar film has more strength in a vacuum condition. Finally, an experimental layout figure was draw according to all above the considerations. In conclusion, this work is a preliminary development of a heavy ion identification device. It could be useful for the analysis of mixed heavy ions in the ECR ion source, which is used in test experiments for the single event effect.

Keywords

• x-ray spectroscopy
• single event effect
• ecr ion source
• photon detector