Micro-pore optic developments for x-ray imaging

Paper number

IAC-06-A3.P.2.09

Author

Ms. Kotska Wallace, European Space Agency (ESA)/ESTEC, The Netherlands

Coauthor

Dr. Marcos Bavdaz, European Space Agency (ESA)/ESTEC, The Netherlands

Coauthor

Mr. Ray Fairbend, France

Coauthor

Mr. Maximillien Collon, The Netherlands

Coauthor

Dr. Michael Krumrey, Germany

Year

2006

Abstract

To enable access to ESA’s planetary missions, new technologies which allow mass and volume reduction of optical components for x-ray imaging are essential.  Technology associated with missions such as ESA’s XMM-Newton is not compatible with the demanding mass requirements for planetary explorers that may conduct remote, planetary, x-ray imaging.  Therefore the development of future x-ray optics has been actively pursued by ESA, in collaboration with Photonis and cosine Research BV.  Photonis’ expertise in micro-channel plates with cosine Research’s expertise in metrology, automation and analysis, has been used to develop a manufacturing technique to extrude high quality, square fibres, which are used to form glass plates with square micro-channel pores.

At Photonis, a purpose built tower has been constructed to draw and measure to high precision square fibres, composed of core and cladding glass, in an automated process.  These fibres are stacked and fused into a square block, which is re-drawn to form multifibres.  Multifibres can be stacked into a radial configuration and fused into a block, from which plates can be sliced to form part of an optic.  Each plate is polished and etched to remove the core glass.  What remains is a monolithic block formed with concentric walls of glass rings, supported by glass pillars.  The inner, tangential walls of the concentric rings will be used as the grazing incidence, reflective surfaces to focus x-rays.  Matching plates are deformed in a slumping process, such that each plate approximates the radius of one part of the tandem pair of a Wolter I configuration.  The tandem of micro-pore plates are aligned, mounted as a matched pair, and form one segment of an x-ray focusing optic.

To improve x-ray reflectivity, processes to coat the channel surfaces with elements such as Ni have been investigated.

This paper discusses the manufacture and assembly of the optics.  Results are presented of x-ray measurements, performed with ESA and cosine Research using the four-crystal monochromator beamline of the Physikalisch-Technische Bundesanstalt at the BESSY-II synchrotron radiation facility, on multi-fibres, sectors and slumped sectors of both coated and uncoated square, micro-pore material.  Measurements are performed to determine the x-ray transmittance, x-ray reflectance of the channel walls, radial alignment and slumping radius of the pores.  Results allow deduction of the overall performance of an x-ray optic as pertains to overall transmission and focussing characteristics of optic plates.  Results of microscope and SEM inspection of the channel walls and coating are also presented.

Abstract document

IAC-06-A3.P.2.09.pdf

Manuscript document

IAC-06-A3.P.2.09.pdf (🔒 authorized access only).

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