Very occasionally, the description of a company as 'unique' looks as if it might be justified. Take NTE Vacuum Technology, tucked away on a small industrial estate near Poole Harbour.
To boldly go ...
OVER 30 years NTE has developed a set of skills which have embedded it as a supplier to some of the world's most advanced technology organisations, including CERN, Culham, Rutherford Appleton, and the UK Astronomy Technology Centre. The company is headed by directors Alan Bailey and Eric Kennedy, and its core strength lies in its ability to provide the housings, vessels and fabricated structures which contain the electronics for projects such as SCUBA 2 - the latest generation of a highly specialised camera for the use in 'submillimeter' astronomy. General requirements include high accuracy, suitability for low temperature and /or high vacuum environments; NTE's success is based on expertise in welding and design techniques, and use of highly rigid machine tool technology.
You might imagine stainless steel to be the preferred material for vacuum chambers. However, for certain applications aluminium has some important advantages. For example it is a third of the weight which is important when the chambers are attached to the giant telescopes in Hawaii and Chile; and in nuclear physics applications the chambers are often subjected to high radiation – so aluminium's half life of 24 hours is extremely attractive compared to 22,000 years for stainless steel.
'One of our specialities is making large aluminium vacuum chambers/vessels' says Bailey. In this field NTE is probably the only serious contender in the UK, and one of a handful in Europe. Welding of aluminium to high vacuum standards is far harder than for stainless steel and demands completely different techniques: The first aluminium chamber of any size was in the 1980s, when NTE won the contract, against European competition, for 24 vacuum chambers for the Aleph detector at CERN. Kennedy elaborates: 'The physics demanded that the chambers were made of aluminium, with walls not thicker than 6mm, otherwise the particles would not reach the chambers fitted within them. Twelve of these were mounted on each end of the detector, with only 3mm clearance between them; the welding had to be perfect, and distortion kept to the very minimum, A lot was learnt which has enabled us to offer our expertise for other major projects.
The value of this was emphasised eight years ago with a phone call from the Royal Observatory, which was having problems in procuring an aluminium vacuum vessel, Rutherford Appleton suggested that NTE was the only company with the appropriate skills. 'They came down from Scotland the next day. They'd procured an aluminium casting 18months previously' recalls Bailey and as it was being machined they were finding blowholes in the casting - and you can't get an o-ring seal where there's a blowhole. They'd been cutting bits out and putting bits in - and they were getting in a mess.
'They asked if we could make it; we said we'd have to redesign it on our CAD system as a welded fabrication, but giving them all the features they required. They liked our solution and gave us an order which we completed in under 8 weeks. We've since done all but one of their projects; the biggest is SCUBA 2 - really a giant digital camera - that was fitted to the James Clerk Maxwell telescope in Hawaii. We don't make the clever bits inside such as the imaging detectors or the 1K and 4K refrigerators; we make the hardware such as the vacuum chamber, optical bench, liquid nitrogen tanks etc; our strength is working with customers helping with design through to final testing and acceptance:
Current projects include work for ALMA – Atacama Large Millimeter/submillimeter Array (typically, an international collaboration, between Europe, Japan and North America in cooperation with Chile); and for LIGO, a USA-based experiment looking at gravitational wave forms. Both projects have generated contracts which run through to 2009-2010.