Monday, November 17, 2014

Medium Resolution with pinholes in CD18

Here the analysis of medium-resolution spectra taken with the pinholes for the purpose of finding best focus and best detector position.
Data is from CD18 with files from gascell.lab.00385.fits - gascell.lab.397.fits

I used C2H2 with the gas cell at the 4th order Q-branch (wn0=731cm-1). I had the detector subarray mode to record only the center 512 rows. The OTPAT was N6D0.

First I took the C2H2 spectra, moving the echelle mirror driver in +1 turn increments from 7-12.
Then I rinsed the cell and took the same sequence of images from 12-7T.

To remove the beam offset between c2h2 and rinse, I used the interpolate function in IDL. This seemed to work very well for removing the continuum between the emission lines. A shift precision of 0.5 pixels was all that was needed.

I /twod clickfit a set of 16 of the best separated emission lines. Below are plotted the fwhm1, fwhm2 and fwhm1/fwhm2.