The Physical Foundation of Grenz-Ray Therapy
About six years ago, Dr. Gustav Bucky invited me to work with him on the investigation of the physical and clinical foundations of over-soft roentgen rays, which he had just introduced into practical use. We attempted to determine the wave lengths of the soft rays used by Dr. Bucky and to devise practical methods of measuring the quality and quantity of these rays, publishing the results in various papers, including those in the American Journal of Roentgenology and Radium Therapy,1 and also in Dr. Bucky’s book.2
Although considerable progress has been made in the past few years3 in the clinical application of Grenz rays, the physical foundations have essentially remained the same. In the following presentation, therefore, some of the old data will necessarily be repeated and the few new developments will be added.
During the past few years, the name “Grenz,” or border, rays has been used more and more in the literature to designate roentgen-ray beams of an average wave length of about 1.5 to 2.5 Angstroms, or of half value layers of 0.015 to 0.03 mm. of aluminum. Although from the biologic and clinical points of view the term “borderline rays” has its justification, it must be emphasized here that physically these rays form only a small part of the large spectrum of roentgen rays which has been known for many years.
A Grenz-ray apparatus is shown in Fig. I. The main transformer, the filament transformer, and the Grenz-ray tube are contained in a separate. . .