DESIGN AND CONSTRUCTION OF A VACUUM CHAMBER FOR THE 40 CM BENT CRYSTAL X-RAY SPECTROGRAPH

The design and construction of a vacuum chamber for the 40 cm bent mica crystal transmission (Cauchois type) x-ray spectrograph are described. Use of this vacuum chamber facilitates recording x-ray spectra in the wavelength range from 1.5 angstrom to 4 angstrom which are otherwise difficult to record when the spectrograph is kept in air. The time required for recording the spectra in this wavelength range has been found to be reduced to nearly half of that without the use of a vacuum chamber; the contrast of the spectrograms has also been found to improve.