In the following description the telescope is assumed to be parked pointing to
the zenith, with the spectrograph mounted. Figure
shows schematically the main optical components of the spectrograph. These
are:
The following Schott glass colour filters are available: BG28, BG38, UG1, GG385, GG395, GG495, RG630, RG695, RG830. Filters are 25 mm in diameter and 2.5 mm thick.
Two ND filters, 25 mm in diameter and 2 mm thick, are available: ND=1.42, 3.0.
The slit assembly is interchangeable so as to allow the
use of a number of slits of fixed width. Two slits are available, of
widths 73 m and 110
m (1.0 and 1.5 arcsec respectively).
For a typical
slit-to-detector reduction factor of about 4.1 (weakly dependent on
the angle of incidence on the grating) these slit
widths project to approximately 18
m and 27
m at the detector.
Access to
the slit assembly and optical components is by removing the
side-panel. The slit position angle can only be set manually by
rotating the instrument turntable with the telescope at zenith park.
Table: Characteristics of gratings for the Richardson Brealey Spectrograph
[ TIFF ]
Figure: The JKT Richardson-Brealey Spectrograph