Glyndŵr University's mirror polishing milestone

The Glyndŵr University team have polished a 1.5m optic for the E-ELT down to just 7.5nm.

The university team have achieved another world first by polishing an optic down to 7.5nm. Credit: Glyndwr University
Published: June 25, 2014 at 12:00 pm

Last week engineers blasted the top off the Cerro Armazones mountain in Chile in preparation for ESO’s E-ELT, set to be the largest optical telescope in the world.


On the same day there was another world-first – this one a little closer to home.

Scientists at Glyndŵr University in Wales revealed they had polished a 1.5m optic – destined for the E-ELT – down to just 7.5nm, around the size of a haemoglobin molecule.

This is the first time such a level of accuracy has been achieved and was done so using computer-operated machinery and the University’s own polishing process.

“The leveling of the mountain top is very exciting and provides confidence to those on the periphery that this ground-breaking venture is going ahead,” said Project Manager Tony Fox-Leonard.

“It is coincidental that it happened as we completed yet another segment to meet the demanding requirements of the optics for the E-ELT.

“Reaching 7.5nm is a significant achievement by the team here in St Asaph and marks another major milestone for the UK’s optical manufacturing industry.

“The specifications for the E-ELT primary mirror segments issued by ESO were recognised as severely challenging and bordering on the impossible by the optical component manufacturing industry.

“But we did it, and have gone even further in achieving a measurement of 7.5nm – we must now maintain and improve on that standard.”


This exciting news follows two other achievements by Glyndŵr University: the ability to polish a straight edge on a hexagonal optic and the acceptance from ESO of the only compliant Optical Test Tower, a vital piece of equipment needed to construct the E-ELT.


Iain Todd, BBC Sky at Night Magazine
Iain ToddScience journalist

Iain Todd is BBC Sky at Night Magazine's Staff Writer. He fell in love with the night sky when he caught his first glimpse of Orion, aged 10.


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