This is the seventeenth quarterly report on our echelle project, as numbered above. Our work this quarter has to some extent been directed towards the Spectroscopy Symposium held at Argonne National Laboratory on February 15, 16, and 17. This report consists principally of brief abstracts of the two papers given at this meeting. Progress since the last quarterly report included completion of the echelle comparator calibration, and the successful production and photographing of the desired spectra of praseodymium and erbium in strong magnetic fields. Considerable interest was aroused by these papers, not only because rare earth spectra are being analyzed, but because of the general applicability of our experimental techniques in producing the spectra.

Thorium Procedure: As was mentioned in the last report, ammonium nitrate was substituted for ferric nitrate as a salting agent. Also, the acidity of the nitrate solution was reduced from 3.0 molar to 0.5 molar. the revised thorium procedure is described in the report. Radium Procedure: Work has ben initiated on the procedure of Petrow, Nietzel and DeSesa (Winchester Procedure) to determine if the procedure is suitable for very low level concentrations of radium.

A stainless steel autoclave for superheated water corrosion test was installed and "conditioned". Tests were begun to investigate the feasibility of densifying slip cast stainless steel by means of liquid phase sintering. Attempts to prepare tubular fuel elements by vacuum forming were resumed. Although thick-walled vacuum formed casting have been sintered on the aluminum mandrels without cracking, this has not yet been accomplished with the think sections of interest.