First light: June 1997.
Designed and built by: Astronomy Instrumentation Group, Physics Department, Durham University. Supported by PPARC and the Paul Instrument fund.
Description: ELECTRA is an adaptive optics instrument designed to operate in the visible part of the spectrum. As with MARTINI-III it is housed at Nasmyth focus in the Ground-based High Resolution Imaging Laboratory (GHRIL) at the William Herschel Telescope (WHT). The instrument has a deformable mirror consisting of 76 individual segments. Each of the segments is driven by three (hysteresis corrected) piezoactuators, hence giving it 228-degrees-of- freedom. Hysteresis correction is maintained through strain gages on the piezos.