Spectrograph Upgrade
Current peak efficiency ~8% (cf 2dF 5%)
6dF camera overfilled by spectra at ends of slit and ends of wavelength range.
Existing reflection gratings good but still only 65% efficiency at peak.
Will shortly switch to VPH gratings, 580V (3900A-5600A) and 425R (5350A-7650A) at same resolution. Should reduce losses for both reasons, hope for 50% efficiency gain.
Mirrors coated March 2002 but no efficiency gain.