jdc_thesis.pdf (3.7 MB)
Microchannel Plates in Astronomy and Planetary Science
thesisposted on 2010-05-27, 11:49 authored by James David Carpenter
Since their declassification in the late 1960s microchannel plates (MCPs) have been used as detectors for X-ray and extreme ultraviolet (EUV) astronomy, offering a unique sensitivity in the EUV waveband. The post 1990 era, however, has seen a universal, and unexplained, reduction in EUV quantum efficiency (QE). An analysis of microchannel plate glass composition has recorded variations in along channel composition for the first time. These observations may provide insight into the lost QE problem and present a way forward for the development of future EUV missions. Although originally developed as photon detectors MCPs have more recently been applied as low mass X-ray optics for X-ray astronomy and planetary science, where fluorescent X-rays from planetary surfaces yield information on surface composition. The Mercury Imaging X-ray Spectrometer (MIXS), on the BepiColombo mission to Mercury, will have two instrument channels, both of which use MCP optical elements. The optimisation of the high spatial resolution imaging X-ray optics of MIXS-T is described and the novel MCP collimator geometry for the high throughput MIXS-C channel is introduced for the first time. The performance of both channels at Mercury is predicted. An in situ investigation into the effects of the International Space Station space environment on MCP optics has led to the serendipitous discovery of nanometre scale dust particles in near Earth space and the realisation of filmed MCPs as extremely sensitive cosmic dust detectors. Analysis of the exposed samples and evaluation of the discovery are presented and possibilities for future dedicated experiments are explored. Microchannel plates continue to be an important technology in astronomy and planetary science. This thesis describes developments in traditional MCP applications and the introduction of new ones, all of which will lead to unique measurement capabilities and significant scientific advancements.
Date of award2006-01-01
Awarding institutionUniversity of Leicester