WE‐G‐213‐01: Roentgen and the Birth of Modern Medical Physics

Roentgen and the Birth of Modern Medical Physics – Perry Sprawls Wilhelm Roentgen is well known for his discovery of x‐radiation. What is less known and appreciated is his intensive research following the discovery to determine the characteristics of the “new kind of radiation” and demonstrate its great value for medical purposes. In this presentation we will imagine ourselves in Roentgen's mind and follow his thinking, including questions and doubts, as he designs and conducts a series of innovative experiments that provided the foundation for the rapid growth of medical physics. Learning Objectives: 1.Become familiar with the personal characteristics and work of Prof. Roentgen that establishes him as an inspiring model for the medical physics profession. 2.Observe the thought process and experiments that determined and demonstrated the comprehensive characteristics of x‐radiation. The AAPM Award Eponyms: William D. Coolidge, Edith H. Quimby, and Marvin M.D. Williams ‐ Who were they and what did they do? – Lawrence N. Rothenberg William David Coolidge (1873–1975) William Coolidge was born in Hudson, NY in 1873. He obtained his BS at the Massacusetts Institute of Technology in 1896. Coolidge then went to the University of Leipzig, Germany for graduate study with physicists Paul Drude and Gustave Wiedemann and received a Ph.D. in 1899. While in Germany he met Wilhelm Roentgen. Coolidge returned to the US to teach at MIT where he was associated with Arthur A. Noyes of the Chemistry Department, working on the electrical conductivity of aqueous solutions. Willis R. Whitney, under whom Coolidge had worked before going to Germany, became head of the newly formed General Electric Research Laboratory and he invited Coolidge to work with him. In 1905, Coolidge joined the staff of the GE laboratory and was associated with it for the remainder of his life. He developed ductile tungsten filaments to replace fragile carbon filaments as the material for electric light bulb filaments. Until that innovation light bulbs had a notoriously short life. He later incorporated the ductile tungsten as a filament material for a hot cathode, fully evacuated x‐ray tube, first described in 1912, which allowed higher current and x‐ray output, and greater reliability than had previously been possible. These “Coolidge x‐ray tubes” were far superior to the cold cathode, partial pressure gas x‐ray tubes that had been in use since Roentgen's discovery of x‐rays in 1895. The Coolidge tube w