[4] He gained a PhD degree in physics from Purdue University and worked at Hughes Research Laboratories before moving in 1967 to the California Institute of Technology as professor of electrical engineering.
However, the common method of determining the energy spectrum of energetic particles at that time relied on the use of very large and cumbersome magnetic spectrometers and ionization chambers.
It was at this time in the mid to late 1950s that James Mayer demonstrated the first semiconductor, broad area, spectrometer which measured the energies of the particles rather than just detecting their impact.
These semiconductor spectrometers led to the practical development of many modern materials analysis techniques that have wide spread use today, such as X-ray fluorescence and ion beam analysis of materials, including Rutherford backscattering, ion channeling, and X-ray spectrometry based on alpha particle sources.
His work resulted in more than 750 papers and 12 books which have garnered in excess of 17,000 citations (ISI listed him as one of the 1000 most-cited Contemporary Scientists between 1965 and 1978).
He mentored 40 PhD students and numerous postdoctoral scholars during his academic career at Caltech, Cornell and Arizona State University.