Puerto Vallarta, Mexico. March, 2018
List of Publications
My Career - A Narrative
The story of my career will take us to some interesting places:
-General Electric's Vallecitos Atomic Laboratory in the first years of its operation and the site of the VBWR,
the first privately owned nuclear power plant in the US (issued Power Reactor License No. 1);
-particle accelerators around the world from Berkeley to CERN working on experiments
using sub-nuclear particles to study the strong nuclear force and the nature of
- to an office tower on the outskirts of Paris and a life of 3-piece suits and 3-hour
business lunches, corporate jets, stockholder meetings, presentations to the IAEA
and UNESCO, trying to keep a group of seasoned engineers on good scientific ground
as we carried out feasibility, environmental and economic impact studies of some
of the boldest, most ambitious and, ultimately undoable civil-engineering projects
-to a mountain in New Mexico recovering from burn-out and the wounds of divorce
among a small community of people that you might, though we didn’t, describe as
hippies- embracing nature, the closeness of my daughter as she began her family,
the joy of spending years next door to my first granddaughter while pursuing a deep
interest in mystical and spiritual matters that began when I was just a boy (and
tinkering with programming micro-processors on the side);
-back to CERN to work briefly on an experiment with anti-matter and then on to the
Meson Physics Facility at Los Alamos (LAMPF) to work on an experiment trying to
measure the mass of the neutrino;
-to working as a staff member in the Physics Division behind the fence of secrecy
at the Los Alamos National Laboratory on arms control treaty verification issues;
- to the Nevada Test Site to test the technology for verifying the Threshold Test
Ban Treaty (CORRTEX);
-to the US Mission in Geneva as a member of the US delegation to negotiate the protocols
for verifying that treaty with our Soviet scientific counterparts;
-to the Soviet Test Site in Kazakhstan to verify the yield (power) of an underground
Soviet nuclear test and standing only a couple of kilometers away from that explosion
watching the earth rise to blot out the sky from the forces unleashed thousands
of feet below the surface;
-to negotiating tables in Geneva, Washington and Moscow working out with the Soviets
the details for verifying specific tests while the Berlin wall was crumbling and
Yeltsin was standing on the tank at the Duma;
-to the Russian nuclear test site on the arctic island of Novaya Zemlya, walking
through icy tunnels, toasting vodka in a birch lined sauna with Russian naval officers
who had never before met an American and who once commanded nuclear submarines
(we talked of our families);
-back to physics, to learn about ultra cold neutrons and use computer simulations
to design a source of these particles for use at the Los Alamos Neutron Science
Center (an experiment in fundamental physics is currently under way using this source);
-leading a team at Los Alamos working to provide data to verify that computer simulations
are a reasonable alternative to underground nuclear testing.
Me at 11 on the farm in Oregon.
The seeds of my career as a physicist were planted when I was 11 years old and living
on a farm in central Oregon. It was 1947 and my father took me to Eugene to see
a movie called the "The Beginning or the End?". It was filmed in Los Alamos,
New Mexico, and was about the development of
the atomic bomb. Among the many dramatic scenes of the film, was the first moments
of operation (bringing to criticality) of the world's first nuclear reactor
at Stagg Field at the University of Chicago on December 2, 1942, under the direction
of Enrico Fermi. The film depicted a couple of young physicists standing on top
of the graphite and uranium pile with buckets of cadmium sulfate that they were
supposed to dump into the pile to help shut it down in case of an emergency. I learned
later that one of them was H.L. (Herb) Anderson. The film was a kind of challenge
to the youth of the world by saying that our father's generation had seen the
beginning of the Atomic Age but it was going to be up to us to determine how it
was going to end. This challenge was intensified by President Eisenhower's famous
Atoms for Peace speech to the U.N. in December, 1953, where he pledged the United
States "to find the way by which the miraculous inventiveness of man shall
not be dedicated to his death, but consecrated to his life."
Me at 22 at the controls of the General Electric Test Reactor, Pleasanton, CA.
inspired my youthful idealism and have in fact shaped several important segments
of my career.
Eleven years after watching the movie I was working as a Bachelor's Degree level
physicist for the General Electric Company in its Atomic Power Division at the Vallecitos
Atomic Laboratory in California and I had been licensed by the US Atomic Energy
Commission to operate two different nuclear reactors. Five years after that (1963),
I was hired by Herb Anderson into my first post-doctoral position at the Enrico
Fermi Institute of the University of Chicago. My office was across the street from
Stagg Field. My doctoral research had been done at UC Berkeley under the tutelage
of two of Fermi's students; Emilio Segrè and Owen Chamberlain, who had
jointly received the Nobel prize in 1959 for the discovery of the anti-proton.
Was seeing this movie just a random event in my life? Maybe. Or, maybe it was one
of those little inspirational nudges that come to help you find or stay on your
path. Maybe, it just depends on how you look at it. But the only other movie my
Dad ever took me to see was "Death of a Salesman" in 1952.
My Career - The Timeline
1956 - 1959.
U.S. Naval Radiological Defense Laboratory, U.S. Navy Shipyards, San Francisco, CA.
I graduated from St. Mary's College of California with a BS degree in Physics in January, 1957.
(I was a semester behind my graduating class because of a short detour during the summer
and fall semester of 1954 to the Dominican Novitiate in Ross, CA.) I began my first job
as a Physicist during the Christmas break in 1956 working at the US Naval Radiological Defense
Laboratory at the Hunter's Point Naval Base in San Francisco. I was a member of the Shielding Studies Group, under the
supervision of Dr. William E. (Bill) Kreger, that was part of the Physics Division directed by
Dr. C. Sharp Cook. The work consisted mostly of studying the attenuation of gamma-rays from various radioactive sources
through various thicknesses of various materials. This provided basic and useful information for radiation protection but
was far from research at the frontiers of physics. One of my more interesting assignments was to crawl through the bowels of
a mothballed aircraft carrier with a radiation detector measuring the dosage from radioactive sources located on the carrier's deck
(simulating radioactive fallout.)
GE Atomic Power Equipment Department, Vallecitos Atomic Laboratory, Pleasanton, CA.
In December of 1953, while a sophomore at St Mary's, I had listened to President Dwight D. Eisenhower's Atoms for Peace
speech to the UN.
I was inspired by his vision of turning the most powerful force yet discovered (the conversion of mass into energy, E =mc2
) into a boon for mankind.
In the time period 1956-1957, the US government began supporting the development of commercial nuclear power by the General Electric Company and the Westinghouse
Electric Corporation. So when the opportunity presented itself I applied for a job at General Electric's Vallecitos Atomic Laboratory (VAL)
in Pleasanton, CA.
I was offered a job in the Critical Assembly Unit of the Physics Sub-section and I began working at VAL in June, 1957. My immediate supervisor was Dr Calvin G Andre and the
head of the Physics Sub-section
at that time was Dr Toma M. Snyder. My work involved
doing experiments on the Dresden Critical Assembly (DCA), a small scale prototype of the Boiling Water Reactor GE was building for the Dresden
Generating Station at Morris, IL. (This was the first privately financed nuclear power plant built in the US.)
Measuring f in the DCA.
My first technical report.
The most important work I did there was to design and carry out an experiment
to measure what is called the thermal utilization factor, f
, of the Dresden reactor core. This factor
represents the ratio of thermal neutrons absorbed in the nuclear fuel to the number of thermal neutrons absorbed in all the materials in the core. This work resulted in the publication
of my first technical report and was the subject of my first scientific talk given at a conference of the American Nuclear Society
in Gatlinburg, TN, in June, 1959.
In addition to the DCA, the Critical Assembly Unit used for its research a small test reactor known as the NTR (Nuclear Test Reactor). As part of my duties I sought and was granted licences by the
Atomic Energy Commission to operate both of these reactors.
Another facility operated by the Physics sub-section was an IBM 650 computer. By today's standards this was a very primitive machine. Its memory storage was a rotating magnetic drum that held all
of 40kb of data (4000 10 digit words) and its input device was a punched card reader (80 column Hollerith cards). My initial interaction with the machine was through assembly (machine) language programming. I remember thinking
how dumb this machine was because it took so many machine instructions to do something as simple as calculating 2+2=4. However, because once programmed it never made a mistake and never got tired, I was pleased
to have such a tool for eliminating much of the tedious work involved in data analysis and scientific calculations. In 1957 the first high-level programming language, FORTRAN, was released which I quickly
and eagerly learned. My ability to eliminate tedious calculational work took a huge leap forward but the IBM 650 was inadequate for the purpose. So I began writing FORTRAN programs to do the work I was doing at VAL
using the IBM 704 computer then located at the Standard Oil Building in San Francisco. The enjoyment I experienced at the logical thinking and planning associated with computer programming and the satisfaction I felt at eliminating work and drastically increasing my productivity
are factors that played a role in much of my career and, in fact, have stayed with me to this day.
In late 1958 I began working as an Analyst - Process Physics
in the Reactor
VBWR photo shoot. That's me on the left.
Operations Sub-section at VAL directed by Samuel Untermyer II. My duties included studies and analyses pertinent to the operation of the VBWR and the General Electric Test Reactor (GETR).
Some of the memories of that period of my work at VAL:
--Participating in the initial start-up of the GETR - looking down into the pool surrounding the core and watching the blue light of the Cherenkov radiation begin to
glow brighter as the reactor approached criticality;
--Measuring the initial neutron flux in the GETR;
--Giving lectures on reactor physics to the crews of the USS Nautilus, the first US nuclear powered submarine;
--Meeting Ronald Reagan, then host of the GE Theater;
--Participating in a photo shoot in front of the VBWR for a national magazine ad campaign with Joyce Myron, a
winner of the (scandalous) $64,000 Question
TV quiz show. Her topic was "atomic energy" and that's a slide rule she's holding in the photo on the right.
(For my current thoughts on the failings of the first generation of nuclear power and the promise of the newest generation for producing safe, abundant, zero-emissions electricity,
please see my article Atoms for Peace: Fulfilling Eisenhower's Pledge. in Colombe magazine on this website.
After only a short while at VAL, it became clear that if I wanted to advance professionally to any position of management or authority in the world of Physics that I would need a Ph.D degree.
(What some of the people in the Physics Sub-section referred to as the "union card".) Having graduated from a small liberal arts college (I was one of only four physics majors in my class) I did not
have high expectations for gaining admission to graduate school.
Fortunately, at that time the University of California, Berkeley, was offering off-campus courses in Physics
at Lawrence Livermore Laboratory. So I enrolled in a series of these courses and found that I did well and could hold my own against students from a more technically oriented background. Two of the courses
I remember most clearly were a course in graduate level Classical Mechanics taught by H. Pierre Noyes
and a course in Nuclear Physics taught by R.S.(Steve) White. Both of these teachers, as well as Calvin Andre at VAL, encouraged me to apply for admission to the Ph.D. program at UC Berkeley and supported me with very helpful
letters of recommendation. I was interviewed by Professor A. Carl Helmholz, Chairman of the Physics Department and was admitted to UC Berkeley as a graduate student beginning in the fall semester of 1959. I also applied
for an educational leave with a living allowance from General Electric which they generously granted me. My family and I moved from Livermore to Berkeley in the summer of 1959. In the fall, I began my course work and
preparation for 'the prelim exams that would allow me to enter the research programs as a Ph.D. candidate.
1959 - 1963.
University of California, Physics Department, Berkeley, CA.
Studying for the "Prelims".
The first two semesters were devoted to graduate class work and studying for the "preliminary" exams. I did have a summer job in 1960 at the Vallecitos Atomic Laboratory where I worked in the Experimental Reactor Physics group.
In the spring semester of 1961 I completed all of the course work required for a Ph.D. candidate. Some of the highlights of that period were:
taking classes on
S Matrix theory from Geoffrey Chew (this was the most promising theory of strong interactions before the discovery of quarks and quantum chromodynamics);
and, giving a presentation on the (KLong
meson system to a seminar chaired by Steven Weinberg (this was before the discovery of CP violation in this same meson system in 1964 - a fact that Weinberg incorporated in the Standard Model of particle physics for which he won the Nobel Prize in 1979).
In January of 1961 I had taken the dreaded prelim exams.
At that time the exams consisted of many hours of written exams in all
the basic subject areas of physics and an oral exam before a committee of professors who were free to ask any questions they wanted in any area of physics. With regard to
the orals I was advised by a number of fellow graduate students to do whatever necessary to avoid having Professor Emilio Segrè on my committee. Professor Segrè
had been a student of Enrico Fermi in Italy and had a reputation for demanding a great deal from students - particularly, his own. He had also just won (together with Owen Chamberlain, another student of Fermi)
the 1959 Nobel Prize for the discovery of the anti-proton.
As luck would have it, Segrè was assigned as the chairman of my oral exam committee. This was a challenge I felt I could not refuse. So I tucked a baby sock from each of my two little girls under
my shirt as "my ladies' favors" and entered the exam room "as a knight" prepared to do battle for my family's future. The exam went very well and I remember actually enjoying the experience of having
the undivided attention of such a distinguished group of physicists. One of the questions I remember that Segrè asked me was to describe J.J. Thompson's experiments that led to the discovery of the
electron in 1897. After the exam I was surprised and honored when Professor Segrè asked if I would like to join his research group, the Segrè-Chamberlain group,
at the Lawrence Berkeley Laboratory (known in those days as the Ernest O. Lawrence Radiation Laboratory
, or, more simply, as the Rad Lab
.) I accepted even though I had been warned
that one of the Ph.D. candidates Segrè had taken on had been there for 7 years.
Lawrence Radiation Laboratory (now known as Lawrence Berkeley National Laboratory),Berkeley, CA.
My first scientific paper.
The first experiment I worked on as a graduate research assistant was a study of pi-meson production in the collision of protons on deuterons at the 184 inch cyclotron. The experiment revealed a "bump" in the energy spectrum for double pi-meson production that indicated an interaction (a possible resonance) between the two pi-mesons. This was one of the first electronic
experiments (as opposed to the analysis of bubble chamber pictures) to reveal the presence of a resonance possibly representing a new "elementary" particle. The experiment became fairly famous and the "bump" is known today as the ABC effect, named after the initials of its principal authors: Alexander Abashian, Norman Booth and Kenneth Crowe. The ABC experiment was a forerunner in what
became a world-wide industry of "bump hunting" that revealed an entire "zoo" of elementary particles. It was the complexity of this zoo that led to the development of the quark model that has been incorporated into the Standard Model of particle physics. I was included as one of the authors of the ABC papers, along with fellow graduate student Ernest Rogers, and these papers became my first peer-reviewed
Particle experiments then and now involve the use of beams of particles produced in complex facilities called particle accelerators. These facilities typically operate 24/7 and the beams they produce are tightly scheduled with "beam time" being divided among the
various experiments being done at the facility. This scheduling is usually done by a committee and the researchers working on any particular experiment divide themselves into work-shifts to accommodate the around-the-clock nature of their assigned "beam time". The graduate students within a
particular research group will typically help each other out by doing shift work on one another's thesis experiment.
In this way I gained experience working on a number of experiments at the Bevatron (where the anti-proton was discovered) and the 184 inch Cyclotron. I helped some of Owen Chamberlain's students who were doing research with one of the world's first polarized proton targets (using solid crystals of La2
O). These targets were based on
the physics of Nuclear Magnetic Resonance and their development at Berkeley was part of the R&D leading to the technology of N
maging, known today as MRI (the "N
uclear" adjective has been dropped out of deference to the public's fear of all things nuclear).
Another experiment that I contributed to during this period was an experiment in weak-interaction physics to measure the capture rate of mu-mesons in He3
. One of the notable features of this experiment was that the
Atomic Energy Commission entrusted us with a loan of a significant fraction of the total world supply of He3
gas. (The experiment helped establish the universality of the V-A Fermi interaction in weak interactions.) The experiment was
led by Norman H. Lipman, a post-doc from the UK in the Segrè-Chamberlain group, and resulted in the Ph.D. thesis for Robert J. Esterling. My association with Bob and Norman Lipman continued long after we had all left Berkeley.
My Ph.D. Thesis Experiment.
Norman Booth (the "B" in the "ABC" experiment) was also a post-doc in the Segrè-Chamberlain group. We and our families became close friends. Norm also became a mentor to me, helping me with my Ph.D. thesis experiment. My principal
interest was in strong interaction physics. (The strong nuclear interactions are produced by the strong nuclear force that holds the nucleus together. The weak nuclear force is responsible for the radactive decay of the nucleus and for the fusion
of nuclei in thermonuclear reactions.) One of the research objectives of the Segrè-Chamberlain group at that time was to provide a complete set of measurements of the scattering of pi-mesons off of protons at a pi-meson energy of 310 MeV.
By the time I joined the group, all of the straight-forward scattering experiments had been done. So I chose to do, with Norm's help, the remaining difficult challenge of measuring the effects of nuclear spin on charge-exchange scattering. In this type of scattering,
a negatively charged pi-meson interacts with a proton producing in the final state a pi-meson with zero charge and a neutron.
The LH2 target area and the entrance side of the LHe polarimeter.
The exit side of the LHe polarimeter. (Some equipment has been removed for easier viewing.)
The experiment consisted of measuring the spin (polarization) of the neutron emitted in this reaction as a function of the
scattering angle (the angle between the incoming negative pi-meson and the outgoing neutron.) The beam of negative pi-mesons was produced by the 184-in cyclotron, the protons were present in a target of liquid hydrogen (LH2
, at 20.3 degrees above absolute zero) and the
neutrons were detected by their scintillations in a liquid Helium target (LHe, at 4 degrees above absolute zero). The LHe target was surrounded by 4 plastic scintillation neutron detectors at fixed angles chosen such that the spin of the neutron at a known energy would produce a
known asymmetry in the angular distribution of the neutrons scattered by the LHe. The LHe detector and the 4 surrounding neutron counters fixed to a rigid wooden platform constituted a LHe polarimeter that could be rotated around the LH2
target. The energy of a neutron entering the polarimeter
was determined by measurements of the time it took the neutron to arrive from the LH2
and the amount of energy it deposited in the LHe detector.
Norm Booth standing in the LHe polarimeter (under construction.)
Norm Booth, me and daughter Diana at the beach (June 1962).
I was fortunate to be graduate student, doing what was then called "high energy physics", at a time when research in
this area could still be done by small teams of people. Aside from me, the experiment was done with the help of two
post-docs (Norm Booth and Norm Lipman) and four other graduate students (Bob Esterling, Dave Jenkins, Olav Vik, and Hugh Rugge).
All of these people had other responsibilities and agendas so, aside from manning the data collection shifts during our allotted
beam-time, I was able to do almost all of the work required for the experiment (mostly under the guidance of Norm Booth). This included: the design of the experimental hardware
(except for the LH2
target) and the supervision of its construction in the lab shops; the design, assembly and testing of
the data collection electronics; developing the FORTRAN program (HEPOLE) required for and carrying out the reduction of the raw data to a
polarization measurement; using the PIPINAL data fitting programs to find the effect of this measurement on the scattering matrix that describes
the pion-nucleon interaction at 310MeV.
The PIPINAL programs (developed during previous researches of the 310 MeV pion-nucleon reaction) were based on what is called a partial-wave analysis
that finds (through statistical Chi-squared minimization) a finite set of parameters (called phase-shifts) that define the scattering matrix and fit the
available scattering data.
My thesis cover page signed by Professors Emilio Segrè, Lawrence Grossman and Charles Zemach.
Prior to this experiment it was found that a set of 10 parameters would provide an adequate fit to the data.
showed definitively that 14 parameters (F-waves) were required to fit all of the then available 310 MeV scattering data. The data fitting resulted in two statistically
acceptable F-wave solutions. Years later, measurements at 310 MeV using a polarized proton target, comparison with experiments at nearby energies and
comparison with an energy dependent phase-shift analysis carried out by L. David Roper, showed a statistical preference for just one of the solutions presented in my thesis.
Most of the data taking for the experiment was completed in late 1961 and early 1962. All of the data analysis was completed in 1963 and on May 16 of that year
I took and passed my Ph.D. qualifying exams. The subjects of the exam were: my thesis; Pion Nucleon Physics; and, Nuclear Physics. The committee consisted of Professors Burton Moyer (Chairman),
Robert Tripp, Emilio Segrè, Charles Zemach, and Lawrence Grossman (Nuclear Engineering). I left Berkeley in September of 1963 to take up my first post-doc position. This was 4 years after entering UC and a little over 2 years after joining the
Segrè-Chamberlain group. The 7 year jinx was definitely broken.
I completed writing my thesis during my first year as a post-doc and my Ph.D. was officially granted in September, 1964. The thesis was first published as a
Rad Lab report, UCRL 11140, on June 26, 1964. The results along with updated information about the phase-shift solutions were published years later in a journal article: Neutron Polarization in π-p Charge-Exchange Scattering at 310 Mev
R.E. Hill, N.E. Booth, R.J. Esterling, D.A. Jenkins, N.H. Lipman, H.R. Rugge, and, O.T. Vik,
The Physical Review D, Vol 2, No 7, 1199-1204, 1 October, 1970.
1963 - 1966.
University of Chicago. Enrico Fermi Institute for Nuclear Studies. Chicago, IL, and
Argonne National Laboratory, Lemont, IL.
In the summer of 1962 Norm Booth left Berkeley to take up a position at the University of Chicago where he was expected to establish a new group at the Enrico Fermi Institute for Nuclear Studies to
carry out experimental research in particle physics. The particle accelerators available for the group's use were the Chicago Cyclotron in the basement of the Institute and a brand new accelerator
called the Zero Gradient Synchrotron (ZGS) being built at the Argonne National Laboratory outside of Chicago.
Shortly after arriving in Chicago, Norm began lobbying me to join him as a post-doc and help get the new group up and running. This was contingent on me passing the qualifying exams but he wanted me to join him
even without finishing the writing of my thesis. Val Telegdi, who I had met at Berkeley, was also urging me to come to Chicago.
I passed my qualifying exams (pretty much assuring my Ph.D.) on May 16, 1963, and accepted Norm's offer. On June 14, 1963, Herbert L. Anderson, former student of
Fermi and Director of the Enrico Fermi Institute for Nuclear Studies offered me a position as a Research Associate (post-doc) at the Institute. Being in rather an urgent need of a decent salary (I had three daughters by then)
I accepted with the understanding that I would complete writing my thesis in Chicago. On September 16, 1963, my family and I left Berkeley and flew to Chicago to begin the next chapter in our lives and my professional career. Norm arranged
for us to take over the rental of a pretty little coach house in Kenwood, near the University, being vacated by Professor Richard Dalitz (a prominent theoretical particle physicist) who was moving to Oxford University.
By the time I arrived in Chicago several graduate students had joined Norm's group with the expectation of doing their thesis research under his guidance. A collaboration had been established with Akihiko Yokosawa and Shigeki Suwa,
physicists at the Argonne National Laboratory, who were building a Polarized Proton Target almost identical to the one that Owen Chamberlain and his group had developed at the Rad Lab
in Berkeley. This target was slated for use in
some of the first experiments scheduled for running at the ZGS, where first proton beam acceleration had occurred on September 18, 1963. My duties at the Fermi Institute were to help train and guide the graduate students in their thesis research, some of which was to be done at
the Chicago Cyclotron, and to help design the first experiments at the ZGS using the new Polarized Proton Target. The capability of the group was greatly enhanced by the arrival a year or so later of R.J. (Bob) Esterling, a fellow graduate student I had worked
with at Berkeley, who had accepted a post-doc position as an Enrico Fermi Fellow at the Institute.
Another of my duties was to participate in the Thursday afternoon seminars at the Institute run by Professor Gregor Wenzel. The seminars were relatively small and intimate and Wenzel made sure that everyone participated.
I found this to be somewhat intimidating because of the prominence of many of the staff at the Institute as well as the
stature of many of the guest participants. My office at the Institute was just down the hall from J.J. Sakurai and Yoichiro Nambu (Nobel Prize in 2008) and one of the regular participants in the seminars was the astrophysicist S. Chandrasekhar (Nobel Prize in 1983).
Some of the guests I remember most clearly were Eugene Wigner (Nobel Prize 1963) and John Archibald Wheeler (who became one of my all time heroes of physics).
Chicago Cyclotron Experiments.
Some of the experiments at the Chicago Cyclotron I participated in while at the Institute were a search for 5
H and a measurement of the spin-spin correlation (CNN
) in proton-proton scattering.
In 1963 B. Nefkins had reported an effect seen in studying the absorption of gamma-rays (320 MeV bremsstrahlung) in 7
Li that he attributed to the formation of 5
H. A number of subsequent experiments did not find any evidence of a
H isotope. Our experiment made use of the Chicago Cyclotron's pion beams to study the absorption of pions by 7
Li and we also found no evidence of a stable 5
H isotope. Our results were published in: Still Another Unsuccessful Search for 5H
N.E. Booth, A. Beretvas, R.E.P. Davis, C. Dolnick, R.E. Hill, M. Raymond, and D. Sherden, Nuclear Physics
, 233-7, 1968.
To carry out the CNN
experiment we scattered a beam of polarized protons created in the Chicago Cyclotron off of protons in the Polarized Proton Target that we had brought from Argonne with the help of Aki Yokosawa and the cooperation of the ZGS Program Committee.
was determined by measuring the angular distribution of protons scattered from the target when the polarizations of the incident and target protons were either parallel or anti-parallel (++,--,+-,-+). CNN
was measured at angles between 50 and 90 degrees (center of mass)
and at 5 different proton energies between 305 and 415 MeV. The experiment was useful in determining the correct theory for predicting nucleon-nucleon scattering in this energy range. The results were published in: Measurements of CNN in Proton-Proton Scattering
, A. Beretvas,
N.E. Booth, C. Dolnick, R.J. Esterling, R.E.Hill, J. Scheid, D. Sherden, and, A. Yokosawa, Rev Mod Phys.
, 536-7, 1967.
Polarization in π- + p Elastic Scattering at 2.08 GeV/c.
Shigeki Suwa, Akihiko Yokasawa, Norman E. Booth, Robert J. Esterling, and Roger E. Hill
Spin and Parity of the N(2190).
A. Yokasawa, S. Suwa, Roger E. Hill, Robert J. Esterling, and Norman E. Booth.
In 1962 and 1963 there were published reports of "bumps" in the the total cross-section measurements of π-
proton elastic scattering in the π-
momentum regions around 2 GeV/c.
These bumps represented the possible existence of new particles (resonances) but total cross-section measurements are insufficient to definitively establish that a "bump" is indeed a resonance much less
to determine the "quantum numbers" (total angular momentum, J, and parity, P) that define the nature of the resonance.
π-p Elastic Scattering Between 1.7 and 2.5 GeV/c.
Roger E. Hill, Norman E. Booth, Shigeki Suwa, and Akihiko Yokasawa.
Our collaboration decided to measure the differential cross-section (angular dependence) and polarization (proton spin dependence) in
+ p elastic scattering at 5 different π-
momenta that spanned the region where the bumps had been observed. These measurements were made with the Argonne Polarized Proton Target. The analysis of the data
took several years and resulted in three publications. One of our principal findings was that the bump at 2190 MeV did exhibit resonant behavior and had a JP
value of 7/2-
. This is now known as the N(2190) or G17
We also verified that the Δ(1950) resonance had a JP
value of 7/2+
After three years as a post-doc at the University of Chicago the normal career path would have been for me to seek a tenure-track academic appointment at a University that supported experimental particle research.
However, in January of 1966 I had received an offer of a three year Fixed Term Appointment (a second post-doc) from G.H. (Godfrey) Stafford, the Director of the Rutherford High Energy Laboratory in England. After leaving Berkeley, Norman Lipman had
joined the Rutherford Lab and had subsequently urged Godfrey to offer me a position. My family and I decided that living in Europe for 2 or 3 years would be a great experience for all of us.
So we decided to take this opportunity and in March of 1966 I accepted Godfrey's offer. After completing some ongoing experiments at the ZGS, we left Chicago for the UK on August 1, 1966. In order to maximize the amount of baggage we could take, we arranged to travel by train and ship.
We left Union Station Chicago onboard the New York Central's 20th
Century Limited and spent a couple of days visiting with some family and friends in New York. On August 4, 1966, we boarded the Cunard Line's Queen Elizabeth
and sailed away to Europe. What was to be a short diversion from the "normal" career path in fact turned out to be a major fork in the road in the life of my family and my career. It would be 12 eventful years before I returned to live again in the US.
New York Central's 20th Century Limited.
On board the Queen Elizabeth, New York Harbor. August 4, 1966.
The RMS Queen Elizabeth (QE1).
Science Research Council, Rutherford High Energy Laboratory, Berkshire, U.K.
(Now known as the Rutherford Appleton Laboratory and now in Oxfordshire, U.K.)