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.

A preliminary mathematical study is made of the maximum expected expansion of barium titanate ceramic. It is noted that there is insufficient physical evidence for a complete answer and some possible mathematical models are discussed and compared.

A device to extend the operation of a beam extraction system is described for low energies where the radiation loss per turn is ineffective. The device consists of a noisy radiofrequency field which excites the radial betatron oscillation

Data obtained in test of Bureau of Mines electrocerium are presented. The cerium was subjected to spectrochemical analysis, x-ray diffraction analysis, thermal analysis, metallographic tests, and high-pressure experiments.

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.

During the past year, three papers covering results of a major series of experiments on intergenotype of blood-forming tissue have appeared, demonstrating successful implantation of isologues normal cells in anemic hosts, permanently correcting their genetic defect in hematopoiesis, both with and without irradiation of the host. Heavy host irradiation was shown ineffective as preparations for implantation of homologous cells of widely different antigenic types.

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.