Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.520495
Title: Microchannel plates in astronomy
Author: Price, Gareth James
Awarding Body: University of Leicester
Current Institution: University of Leicester
Date of Award: 2001
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Abstract:
This thesis describes both round-pore microchannel plates (MCPs) used in energetic pho¬ton and particle detectors and their square-pore offspring, micropore optics (MPOs), used to focus x-rays. A Monte Carlo electron raytracing software package is described that is used to predict the energy and angular distribution of electrons (EDOE and ADOE) in a microchannel electron multiplier's output charge cloud, including saturated operation. The model is shown to agree with experimental evidence. The addition of a micromachined electrostatic lens to the end of a microchannel is modelled and found to have no beneficial effects upon the EDOE and ADOE of the channel. The current state of the art planar and slumped 'lobster eye' square-packed MPOs are evaluated. The best focus (5' FWHM) from a large format (61mm x 56mm), small chan¬nel (10μm side length) planar MPO is reported, together with the observation of high energy (~50keV →65keV) x-ray focusing from large (500:1) aspect ratio channels. The alignment of many small lobster eye MPOs to create a large optic for the Lobster-ISS instrument is discussed and the alignment jig constructed for this purpose is used to measure the bias angles of a Lobster specification MPO. The bias angle is found to be 4 ± 1.5'. The concept of the microchannel conic approximation to the Wolter type I and II x- ray lenses is reviewed. A radially-packed twin MPO Wolter approximation is then tested, which while of poor quality, demonstrates true Wolter II imaging with a peak gain greater than unity. Currently proposed (UK) astronomical instruments that employ MPOs are then discussed in the light of the results from the current generation of MPOs.
Supervisor: Fraser, George Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.520495  DOI: Not available
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