Hind High Vacuum (HHV), a global leader in vacuum and thin-film technology, has bagged a prestigious contract from the Physical Research Laboratory (PRL), a unit of the Department of Space, Government of India, to manufacture and install dedicated mirror coating plant for PRL's upcoming 2.5-metre telescope. The telescope is a part of the Mount Abu Observatory, which is located at the Gurushikhar peak of Mount Abu, Rajasthan, at an altitude of 5,600 feet above mean sea level.
Known as the cradle of Space Sciences in India, PRL, founded in 1947 by Dr Vikram Sarabhai, carries out fundamental research in selected areas of physics, space & atmospheric sciences, astronomy, astrophysics & solar physics and planetary & geosciences.
The mirrors of the telescopes are amongst the most important components to sense radiations from distant sources. These need to be coated with a reflective thin film that aids efficient light collection. The reflective coatings are prone to environmental degradation, which necessitates a re-coating. The existing coatings are stripped clean, and a fresh coating is then applied. The vacuum deposition process applies these coatings to obtain the best properties in terms of reflectivity and durability. As the mirrors are sensitive and one of the most expensive components in the telescope assembly, the coatings are carried out on-site. Thus, a vacuum coater is stationed at on-site astronomical observatories for coating the mirror at regular intervals.
"Astronomical telescopic mirrors coaters require a technologically advanced high vacuum equipment design, engineering and manufacturing. HHV has been globally recognised as a trusted supplier for coaters for telescopic mirrors and has commissioned and demonstrated its coaters at various locations, including demanding high altitudes going up to about 14,800 feet," said Prasanth Sakhamuri, Managing Director, HHV. "The telescope mirrors the size of up to 3700 mm diameter and weighing more than 4,000 kg can be accommodated in HHV coating chambers with a maximum overall dimension of 4,000 × 2,100 mm. The coaters offer an automated and highly reliable process for coating mirrors with aluminium and/or silver-based coatings."
HHV is currently executing an order from Physical Research Laboratory (PRL), Udaipur, to build a mirror coater for handling mirrors of different sizes going up to a maximum of 700 mm diameter. This recent order from PRL re-emphasises HHV's technical competency in this niche area. HHV is continually taking up development activities in this area to integrate its coaters with proven process recipes for the deposition of highly reflective and durable thin-film coating stacks and is looking forward to being a part of various such projects in the future.
