Specifications
Principal Parameters
| Property | specification |
|---|---|
| Observable Wavelength | 4000-8700 A |
| Spectral Coverage | 1500-3000 A width at one exposure |
| Spectral Resolution (lambda/Dlambda) | 8600 (since 2006~) |
| Velocity Resolution | 35 km/s |
| Optimal f-ratio of Telescopes | f/10 or larger |
| Typical Polarimetric Accuracy | 0.05-0.10% |
| Readout Noise | 6 e-(69kHz; default)-3 e- (27kHz) |
| linearity of the CCD camera | 0.2-0.3% |
| limiting magnitude |
mAB= 11 mag (Halpha, 1A resolution, 0.7'' seeing, 4 hours exposure, at UH88 f/31) |
Components
| Component | specification |
|---|---|
| Half-wave Plate | AstroPribor Super-Achromatic Zero-Order Waveplate (APSAW) |
| Analyser |
double Wollaston prism, quarts, separation angle of rays ~6 degrees |
| Cross Dispersers | 300 gr/mm, 750 nm blaze (for red wavelength range) 600 gr/mm, 500 nm blaze (for blue wavelength range) |
| Echelle Grating | 72 gr/mm, blaze angle : 44 degrees |
| Entrance Slit | 0.09 x 0.6mm (0.83 x 9.2 arcsec @ f/10) |
| Glan-Taylor prism | depolarization factor < 5 x 10-5 |
| CCD chip |
EEV 42-40 grade-5 2048 x 2048 pixels, 13.5 um sq. |
| Refrigerator |
Stirling-cycle Refrigerator DAIKIN WE-1000A 1W at 80K |
| CCD controller | Messia-IV and M-Front |
| CCD temperature controller | Lakeshore 330 |