George Samuel Hurst

George Samuel Hurst (13 October 1927 – 4 July 2010) was a health physicist, scientist, inventor, educator and innovator. He developed the omnipresent touchscreen technology and single atom theory. Hurst spent his career at Oak Ridge National Laboratory where he was involved with: neutron survey meters; alpha survey meters; ionizing radiation dosimetry; gas ionization studies; Nevada Test Site gamma and neutron radiation measurements; vacuum ultraviolet (VUV) radiation and the Jesse effect; time-of-flight investigations; electron swarm measurements; study of atomic bomb survivors from Hiroshima and Nagasaki; radiation accident investigations; radiation dosimetry projects for NASA; microdosimetry; one-atom detection and single atom detection; solar neutrino experiments; magnetic monopole detectors; resonance ionization spectroscopy (RIS); and, sputter-initiated resonance ionization spectroscopy (SIRIS).

Life and times
Hurst was born on 13 October 1927 in the rural town of Ponza, Bell County, Kentucky located near Pineville, Kentucky. His father was James H. Hurst and mother was Myrtle Wright Hurst. As a boy, he had a keen interest in Thomas Edison. Hurst grew up on the family farm and came from a large family with two brothers and two sisters. In 2010, he died of a brain aneurism and was buried at Oak Ridge Memorial Park.

Education
Hurst attended high school at Bell County High School in Pineville, Kentucky. At the age of 15, he enrolled in Berea College. In 1947, Hurst received a B.A. degree in physics and a minor in mathematics from Berea College. He attended the University of Kentucky and graduated in 1948 with the M.S. degree in physics. During registration at UK, he met Rufus Ritchie. Ritchie became a longtime friend and the two worked on several projects together. After graduation, they both went to ORNL. In 1959, Hurst was awarded a Ph.D. in physics from the University of Tennessee.

Oak Ridge National Laboratory
In 1948, Hurst was recruited by Karl Z. Morgan and landed a research position at Oak Ridge National Laboratory (ORNL) in the Health Physics Division. His starting salary was $325 per month. He made significant contributions in the development of radiation detectors and instrumentation, neutron dosimetry and spectroscopy, and field sample analysis. While working at Oak Ridge, he earned a PhD in physics from the University of Tennessee in 1959. In 1966, Hurst accepted a position at the University of Kentucky as Professor of Physics.

Neutrons, dosimetry and phantoms
From 1948 to 1950, Hurst worked with Ritchie to develop a fast neutron survey meter and fast neutron dosimetry. The fast neutron dosimetry work continued throughout the 1950s with the added interest in tissue dose. In 1952, the team of Hurst, D.J. Knowles and C. Yochem worked to develop a thermal neutron survey instrument. Hurst and F.M. Glass developed a method of pulse integration by utilizing the binary scaling unit. Hurst explored fast neutron dosimetry and tissue-equivalent phantoms. His team that included J.A. Harter, P.N. Hensley and W.A. Mills studied neutron flux and tissue dose with fission threshold detectors. Around 1955, Hurst teamed with A.C. Upton, F.P. Conte and W.A. Mills to look at the relative biological effectiveness (RBE) that involved mixed radiation fields for acute lethality in various animal models. Additional studies with A.C. Upton, K.W. Christenberry, G.S. Melville, and J. Furth utilized mixed radiation fields to produce lens opacity in various animal models. In 1956 and again in 1980, Hurst utilized threshold detectors to measure neutron spectra in order to determine tissue dose. In 1961, Hurst led a group that performed measurements of the absorbed dose of neutrons, and of mixed radiation field of neutrons and gamma rays. This resulted in the publication of Handbook 75 for the National Bureau of Standards.

Alpha survey meter
In 1950, Hurst and his team developed a portable alpha survey meter.

Gas ionization studies
In 1953, an interest in the ion pair energy production from 5 MeV alpha particles led to nearly 2 decades of research, during which time Hurst studied alpha particle ionizations and excitations in various gases and gas mixtures.

Nevada Test Site
Hurst and the team of L.J. Deal and H.H. Rossi performed gamma and neutron radiation measurements at the Nevada Test Site during Operation Upshot-Knothole for the Atomic Energy Commission. For Operation PLUMBBOB, Hurst was again asked to participate along with Ritchie at the Nevada Test Site to collect radiation dosimetry data for human exposures during the tests.

VUV, vacuum ultraviolet radiation and Jesse effect
The Jesse effect, named after William P. Jesse, may best be described as the increase in ionization produced in a gas by alpha, beta, or gamma ionizing radiations when a small concentration of a gas with a lower ionization potential is present. Hurst utilized noble gases to examine vacuum ultraviolet radiation (VUV) and the Jesse effect. For these efforts, Hurst sought the assistance of Thurmond E. Stewart, James E. Parks, H. Lee Weidner, M. Payne and C. Klots. Hurst performed additional VUV studies separately on Helium, Argon, and Krypton.

Time-of-flight investigations
In the 1960s, Hurst along with L.B. O'Kelly, E.B. Wagner, J.A. Stockdale, James E. Parks, and F.J. Davis investigated time-of-flight electron transport in gases. The group utilized ethylene, water vapor and hydrogen to study and determine time-of-flight electron diffusion coefficients and electron drift velocities for these gases. Hurst led efforts to investigate time-of-flight of electron transport in atomic and molecular gases.

Electron swarm measurement
In the mid 1960s, Hurst pursued researches that involved electron swarm measurement, swarm‐beam techniques and swarm drift to determine electron capture cross sections in heavy water, chlorobenzene, bromobenzene, ethylene and ethylene mixtures.

Hiroshima and Nagasaki
In the 1950s, Hurst went to Japan with colleagues and students Rufus Ritchie, Nello Pace, and Robert E. Smith to conduct studies for the Atomic Bomb Casualty Commission. The team studied the delayed and latent effects with an emphasis on the mortality and morbidity rates among the atomic bomb survivors of Hiroshima and Nagasaki.

Radiation accident expert
The expertise and experience of Hurst were often called upon for matters that involved radiation accidents.

The IAEA asked for and received assistance from Hurst to investigate the Vinča reactor criticality accident that occurred on 15 October 1958 at Vinča, Yugoslavia.

NASA dosimetry projects
In 1965, Hurst prepared a special publication for NASA for radiation dosimetry applications to be utilized for data collection that involved radiation in space. Then in 1986, a technical report was prepared for NASA that looked at the feasibility of a solar neutrino experiment.

Microdosimetry

 * Atomic physics: microdosimetry, 1974.
 * Digital Characterisation of Particle Tracks for Microdosimetry, 1985.
 * A digital approach to neutron dosimetry and microdosimetry, 1985.

One-atom detection, single atom detection

 * Selective Single Atom Detection in a 1019 Atom Background, 1977.
 * A demonstration of one‐atom detection, 1977.
 * One-atom detection using resonance ionization spectroscopy, 1977.
 * Detection of single atoms in particle tracks, 1978.
 * Selective, laser one-atom detection of neutral prompt fission fragments, 1978.
 * One-atom detection in individual ionization tracks, 1978.
 * A Generalization of One-Atom Detection, 1979.
 * Resonance ionization spectroscopy and one-atom detection, 1979.
 * One-atom detection, 1980.
 * Fluctuation experiments on atomic and molecular systems using the one-atom detector, 1982.
 * One-atom detection and statistical studies with resonance ionization spectroscopy, 1985.

Solar neutrinos
In the 1980s, Hurst was called upon by NASA to further explore solar neutrinos.
 * Radiochemical solar neutrino experiment using 81Br (nu, e-) 81Kr, 1983.
 * A Radiochemical solar neutrino experiment using 81Br (ν, e) 81Kr, 1983.
 * Feasibility of a Br-81 (ν, e−) Kr-81 Solar Neutrino Experiment, 1984.
 * A proposed solar neutrino experiment using 81Br (ν, e−) 81Kr, 1985.
 * Feasibility of 81Br (v, e−) 81Kr Solar Neutrino Experiment, 1985.
 * Feasibility of a 81Br (nu, e-) 81Kr solar neutrino experiment, 1986.

Magnetic monopole detectors

 * Magnetic monopole detectors based on He (2 3 S), 1985.

Resonance ionization spectroscopy, RIS

 * Saturated Two-Photon Resonance Ionization of He (2 S 1), 1975.
 * Kinetics of He (2 S 1) Using Resonance Ionization Spectroscopy, 1975.
 * Resonance ionization for analytical spectroscopy, 1976.
 * Observation of New Satellites in the Cs-Ar System Using Resonance Ionization Spectroscopy, 1978.
 * Resonance ionization spectroscopy and one-atom detection, 1979.
 * Resonance ionization spectroscopy, 1979.
 * Resonance ionization spectroscopy with amplification, 1979.
 * Resonance ionization spectroscopy of lithium, 1979.
 * A summary and review of the early history of RIS, 1979.
 * Direct counting of Xe atoms (with RIS), 1980.
 * Resonance ionization source for mass spectroscopy, 1980.
 * Resonance ionization detection of Xe atoms, 1980.
 * Detection of trace amounts of transuranics by resonance ionization spectroscopy of noble gases, 1980.
 * Resonance ionization spectroscopy, 1981.
 * Resonance Ionization Spectroscopy: Counting Noble Gas Atoms, 1981.
 * Resonance ionization spectroscopy schemes for Ar, Kr and Xe, 1981.
 * Applications of resonance ionization spectroscopy in atomic and molecular physics, 1981.
 * Resonance ionization spectroscopy for low-level counting, 1982.


 * Applications of resonance ionization spectroscopy in neutron dosimetry, 1982.
 * Noble Gas Detection Using Resonance Ionization Spectroscopy and a Quadrupole Mass Spectrometer, 1983.
 * Tunable VUV light generation for the low-level resonant ionization detection of krypton, 1983.
 * Selective counting of krypton atoms using resonance ionization spectroscopy, 1984.
 * Resonance ionization Spectroscopy: inert atom detection, 1984.
 * Application of resonance ionization spectroscopy in particle physics, 1984.
 * Experiments on statistical mechanics using resonance ionization spectroscopy, 1984.
 * Searches for fractional charges and superheavy atoms, 1984.
 * Theory of resonance ionization spectroscopy, 1985.
 * One-atom detection and statistical studies with resonance ionization spectroscopy, 1985.
 * Analysis of 81Kr in groundwater using laser resonance ionization spectroscopy, 1985.
 * Weak interaction studies using resonance ionization spectroscopy, 1985.
 * Resonance ionization spectroscopy, 1986.
 * Trends in resonance ionization spectroscopy, 1986.
 * Analysis of 81Kr in groundwater using laser resonance ionization spectroscopy, 1986.
 * Detection of Single Atoms by Resonance Ionization Spectroscopy [and Discussion], 1987.
 * Elemental analysis using resonance ionization spectroscopy, 1988.

Sputter-initiated resonance ionization spectroscopy, SIRIS

 * Sputter-initiated resonance ionization spectroscopy, 1983.
 * Ultrasensitive elemental analysis of solids by sputter initiated resonance ionization Spectroscopy, 1983.
 * Sputter initiated RIS (SIRIS) for analysis of semiconductor impurities, 1984.
 * A search for new elementary particles using sputter-initiated resonance ionization spectroscopy, 1986.

Awards and honors

 * IR-100 Award, 3 awards
 * Union Carbide, Corporate fellow
 * American Physical Society, fellow
 * University of Kentucky, Alumni Association Hall of Distinguished Alumni, member
 * Berea College, D.Sc., honorary degree
 * University of Tennessee, Physics Department, Distinguished Alumni Award, 2005
 * University of Tennessee, Physics Department, G. Samuel and Betty P. Hurst Scholarship Fund; support for physics majors
 * Bell County High School, Pineville, Kentucky, notable alumni

Professional affiliations

 * Florida State University, visiting professor
 * Health Physics Society
 * Scientists and Engineers for Appalachia (SEA), founder
 * University of Tennessee, Institute of Resonance Ionization Spectroscopy, founder, director 1985-1988

Dissertation work

 * Attachment of low-energy electrons in mixtures containing oxygen, 1959.
 * Negative ions of oxygen, 1959.

Patents (15 total)

 * Resonance ionization for analytical spectroscopy, 1976.
 * Method and apparatus for noble gas atom detection with isotopic selectivity, 1984.
 * Method of analyzing for a component in a sample, 1984.
 * Method and apparatus for sensitive atom counting with high isotopic selectivity, 1987.
 * Double pulsed time-of-flight mass spectrometer, 1987.
 * Sensitive, stable, effective at low doses and low energy, 1987.
 * Ionizing radiation detector system, 1990.
 * HVAC system. Radon monitor and control system based upon alpha particle detection, 1991.
 * System for determining health risk due to radon progeny and uses thereof, 1993.
 * Instrument simulator system, 1994.
 * Instrument simulator system, 1995.
 * Touch screen based topological mapping with resistance framing design, 2003.
 * Touch sensor with non-uniform resistive band, 2007.
 * Touch screen with relatively conductive grid, 2010.
 * Multiple-touch sensor, 2011

Private enterprize
Hurst has founded or co-founded five businesses:
 * Elographics, 1971. Developed touchscreen technology. Several patents secured. Electrical Sensor of Plane Coordinates.
 * Atom Sciences
 * Pellissippi International, 1988.
 * Consultec Scientific, 1990.