Stourport, Worcestershire-based ceramic component maker Morgan Advanced Ceramics has secured a contract with Photek to supply hexagonal ceramic insulators for intensifiers used in NASA’s OWL mission.
OWL is the world’s first earth-orbiting system designed to study air showers initiated by ultra-high energy cosmic rays (UHECR). The use of ceramic in the OWL’s ‘eyes’ will allow an accurate image of these particles to be generated and will enable scientists to make significant discoveries about their origins – whether they are harbingers of new physics, associated with hidden dimensions, or generated high-density trapped defects of space left over from the Big Bang.
When UHECRs enter the Earth’s atmosphere, a disk of ultraviolet fluorescence flashes through the night’s sky, travelling at nearly the speed of light, and lasting for only a few tens of microseconds. The OWL’s eyes must therefore be large so they collect as much of the UV signal as possible and it is essential that the intensifiers are accurate to show a true representation of the UV light.
Ceramic was an ideal choice of material for the intensifiers for its electrical and mechanical properties. Ceramic is a good electrical insulator which is an important characteristic for the intensifiers. In an intensifier, a lens focuses an image into a vacuum tube, which is made of ceramic material, and a photocathode at one end releases electrons by the photoelectric effect of the incoming photons.
‘There was an immediate challenge surrounding the design of the component,’ said Yannick Galais, Commercial Manager of Morgan Advanced Ceramics. ‘During the manufacturing process, the component is fired in a kiln and it shrinks by around 20 per cent in size as it is sintered. Tight control of raw material production and the methods used to manufacture the part are essential to ensure that it shrinks evenly in all directions without distortion and cracking.’
The accuracy of the component is paramount. Galais continued: ‘We also had to achieve an extremely tight tolerance of five microns.’
The two companies together came up with a unique 168mm across flats, hexagonal design that enables the intensifiers to fit together easily in a honey-comb style, for maximum collection of UV light.
Morgan Advanced Ceramics has shipped three pairs of the component to Photek, where they have been assembled and taken to Rutgers University, New Jersey for testing prior to installation. OWL is due for launch in 2010 and the project is expected to need more than 100 intensifiers per eye.