Coronado PST n°2
1) Sol'Ex spectrometer: measurement in a collimated beam (f/115)
: Sun => PST (without any lens) => Sol'Ex
Sol'Ex spectrograph : 10 microns x 4.5 mm slit, 80 mm collimating lens, 125 mm imaging lens, ASI290 camera, 12-bit acquisition.
Measured dispersion = 0.075 A/pixel
11 July 2021 - 8h32
while the etalon was exposed to a collimated beam and the collimating
lenses were removed, the spectrum transmitted by the etalon was very
sensitive (width and peak of the fringes) to the orientation to the Sun
Three successive images:
- (1) solar spectrum,
- (2) solar spectrum transmitted by the PST etalon with the knob set to
Ha for f/35 telecentric beam, the etalon is tilted in order to tune on
Ha line at f/115 (near collimated beam).
- (3) solar spectrum transmitted by the PST etalon with the knob set to Ha
for f/35 telecentric beam (same as before), the etalon is set at normal incidence (i.e. position with the peak of the fringes the farthest to the red).