Department of Physics

Dan Miller came to Indiana University (IU) in 1952 after obtaining his in Ph.D. in nuclear physics at Wisconsin University under the direction of Heinz Barschall. His many contributions to the IU Physics department included teaching and mentoring of undergraduate Physics majors and supervising the research of several Ph.D. students. Dan was an able administrator and he served IU in a number of areas, including the athletics committee where he was the faculty representative to the Big Ten Conference.

In 1952, IU had a cyclotron whose construction was completed in 1948. Dan worked on (d,p) measurements with Milo Sampson and (d,p) double scattering measurements with graduate student Chuck Foster. In the 1960s, IU needed to upgrade this cyclotron. Dan decided to upgrade of the Physics department using an NSF Science Development Grant and to also seek support for a much larger cyclotron with a unique design. With the NSF grant the physics department doubled its number of faculty positions and expanded into a number of new research areas. The new separated-sector cyclotron with strong focusing at the edges would provide an outstanding beam resolution.

Funded in 1968, construction of a new building north of campus began in 1970 and the construction of the new 200 MeV cyclotron in 1972. Designed by Martin Rickey and constructed by Robert Pollock, the first beam was obtained in September 1975. First results included observation of nuclear pion production, operation of a (p,n) beam swinger and first results with a high-resolution magnetic spectrometer.

For the next ten years, a number of research programs were undertaken. In 1978 an atomic-beam, polarized-ion source producing high-intensity beams of polarized protons and deuterons was installed. The (p,n) studies by Goodman mapped out the Gamow-Teller Giant Resonance in nuclei from Calcium to Lead. The studies of pion production continued with a dedicated magnetic spectrometer. Dan participated in studies of elastic and inelastic scattering of protons, which identified the role of spin-dependent forces in the scattering of protons above 100 MeV. An overall resolution of better than 100 keVat 200 MeV showed that the unique design of this cyclotron had been verified.

By 1983, it was time to consider another upgrade of the facility. Dan Miller was a co-director of the IU Cyclotron Facility (IUCF) and Pollock, on a sabbatical leave in Europe, learned of the new storage-ring technology being developed to allow acceleration of beams to much higher energy. This seemed like a possible way to extend the range of the experiments at IU well above 200 MeV. By 1985 a preliminary design developed by Hans Meyer and Bob Pollock was submitted to the NSF. The final proposal, approved in 1988, included injecting the 200 MeV cyclotron beam into a 500 MeV synchrotron storage ring, which would use electron cooling developed by the Russians.

In 1988, John Cameron took over the directorship of IUCF. Pollack’s design of a six-sided storage ring had locations for electron-cooling, injection of the 200 MeV cyclotron beam with vertical stacking and three long straight sections for new set of experiments. One would contain an atomic-beam polarized target from Wisconsin for polarized beam – polarized target experiments. Another had a small bend which would allow (p,n) studies above 200 MeV. Meyer and Pollock commissioned these efforts by 1990.

Dan was instrumental in upgrading the magnetic spectrometer on the cyclotron with a polarimeter in its focal plane and a program of precision elastic and inelastic scattering was initiated on the cyclotron. For the next decade, measurements at IUCF provided new information on the spin-dependence of the nuclear force. On the Cooler pp elastic scattering was measured between 200 and 500 MeV using both a polarized Cooler beam and the Wisconsin polarized target, and pn scattering was measured using a polarized deuteron target and quasi-elastic kinematics. On the cyclotron Dan’s magnetic spectrometer was used with pp inelastic scattering and pn with a neutron polarimeter to measure how the nucleon-nucleon force is modified inside nuclei. Sizeable differences were observed leading to a new understanding on the force.

The design of the Cooler had as big an impact on nuclear physics facilities around the world as the cyclotron. In 2003, the NSF halted its support of IUCF. Cameron undertook a conversion of the Cyclotron to a 200 MeV proton cancer treatment facility. It would take advantage of the intense, small beam and the Bragg curve to localize the radiation dose to a tumor near the end of the range of 200 MeV beam in tissue (about 20 cm). The completed Midwest Proton Radiation Institute (MPRI) treated patients for about ten years using two beam swingers to provide a wide range of beam angles on the patient.

When he retired, Dan was very proud that the IU cyclotron would continue to be of service to society. Dan had an enormous impact on nuclear physics. But most of all he will be remembered for his compassionate leadership of both students and researchers.