The Research Career of Subramanian Raman
at Oak Ridge National Laboratory
Fred E. Bertrand
Oak Ridge National Laboratory and Joint Institute for Heavy Ion Research
Oak Ridge, Tennessee 37831 USA
Abstract. Subramanian “Ram” Raman, a distinguished nuclear physicist and senior staff member of the Physics
Division at Oak Ridge National Laboratory (ORNL), died April 8, 2003. In June 1966, Raman joined the staff at ORNL
working in the Nuclear Data Project. This position provided him insights into important open questions in nuclear
structure physics, and the power of “horizontal” compilations of properties across a broad range of nuclei. These insights
would guide Raman’s research interests throughout his 36-year career at ORNL.
As shown by his great variety of publications, Raman’s research career was marked by an intense interest in all
areas of nuclear physics. He published papers on topics ranging from detailed nuclear structure to giant resonances, to
the search for superheavy nuclei, to the scattering of heavy ions. His research resulted in over 200 published papers and
over 3000 citations of his work. It is however, his nuclear data evaluations, both horizontal and vertical, that we most
often remember. His most often cited papers deal with the evaluation and systematics of nuclear data, and he helped
establish many of the “rules” and guidelines for assignment of nuclear level properties. An overview of Raman’s work at
ORNL is presented.
especially non-U.S. collaborators. Those collaborations were not only scientifically productive but they
produced life-long friendships.
INTRODUCTION
On April 8, 2003, the Nuclear Physics
Community and, especially, the Nuclear Data
Community, lost one of its most productive and
distinguished members with the passing of
Subramanian “Ram” Raman. Raman joined the staff
of the Oak Ridge National Laboratory (ORNL) in
June 1966 as a member of the Nuclear Data Project
(NDP). His work in the NDP provided him insights
into many important questions in nuclear structure
physics and introduced him to the power of
“horizontal” compilations of nuclear properties
across a broad range of nuclei. This early data work
would guide his research throughout his 36-year
career at ORNL. When his career was prematurely
ended, he was a Senior Staff Member at ORNL, a
Fellow of the American Physical Society, Scientific
Director of the Oak Ridge Electron Linear
Accelerator (ORELA), Co-editor of the journal
Atomic Data and Nuclear Data Tables (ADNDT),
and author of hundreds of scientific papers.
Raman was always quick to note that, while he
deeply enjoyed nuclear physics research, he
treasured nothing more than his family, and I can say
that he did a wonderful job in that area as well. He
often told us that his best three “publications” were
his three children. All of us who know his wife,
Judy, and his children, Anand, Manya, and Jay, have
been witness to a most loving and closely knitted
family. Nothing was more important to Raman than
his family.
On behalf of the ORNL Physics Division and for
Raman’s family, I would like to thank the
Conference Organizers for establishing this session
in Raman’s memory. It is most fitting that such a
session is held at the International Conference on
Nuclear Data for Science and Technology since
Raman’s work had such a strong influence on
nuclear data. In this paper, I provide an overview of
Raman’s work at ORNL, and I am honored to do so.
However, it is impossible in this brief presentation to
do justice to the career of such a productive scientist.
I know of no other member of the ORNL Physics
Division who had more non-laboratory collaborators,
CP769, International Conference on Nuclear Data for Science and Technology,
edited by R. C. Haight, M. B. Chadwick, T. Kawano, and P. Talou
© 2005 American Institute of Physics 0-7354-0254-X/05/$22.50
21
I hope to provide a flavor of his research, his
productivity, and his nature.
THE EARLY DAYS
Raman was born in 1938 in the small town of
Kollengode in southwest India. He graduated from
high school at the age of 14, and after a few years of
post-high school education, he went to college in
Madras. Raman studied engineering with the goal of
joining the engineering department of the Indian
Railroads. This was a very prestigious job and thus,
one highly sought after. After graduating from the
University of Madras in 1958, Raman took the
examination for the railway job. Although the
technical tests were not a problem (he finished
second in the nation), there was one issue. An eye
examination was mandatory and had to be passed
without glasses. Raman did not pass the eye exam,
and much to the disappointment of Raman and his
family he was not able to join the Indian Railway
System as an engineer. While this was a very
unfortunate time for Raman and his family it would,
of course, be a boon for ORNL.
FIGURE 1. Staff of the ORNL Nuclear Data Project circa
1968. From left to right (front row) – Sharon Spainhour,
Jackqueline Miller, Frances Hurley, Shirley Ball,
Katharine Way, Helen Lambden, Yurdanur Akovali. Back
row – Bruce Ewbank, Suresh Pancholi, Preben Blichertoft,
Jean Vervier, Murray Martin, Subramanian Raman, Hank
Verhuel, and Chimin Chen.
evaluations/compilations. He completed 18 more
horizontal compilations after he left the NDP. My
association with Raman started when I was hired on
the staff of the Nuclear Data Project in 1970. Raman
was given the task to be my NDP mentor and he was
a co-author on my first A-chain evaluation, A = 110
[2]. My wife and I have known the Raman family
since that time, and we are very grateful for their
friendship for all these years.
Raman decided to study abroad. He arrived in
New York City in the summer of 1959. He attended
Rensselaer Polytechnic Institute earning a master’s
degree in electrical engineering. Following this, he
enrolled at Pennsylvania State University and
received a PhD in physics in 1966. Raman accepted
an offer to join the ORNL Nuclear Data Project
headed by Katharine Way. A picture of the Nuclear
Data Project Staff circa 1968 is provided in Fig. 1.
While authoring mass chain evaluations, Raman
would uncover interesting problems that he would
then attack and solve in the laboratory. This is
illustrated in the list below that shows several of
Raman’s research papers in specific mass regions
and the Nuclear Data Sheets that Raman authored for
the same mass region. The correlation is clear.
Raman published his first paper in 1966, based on
his thesis work entitled “Energy Levels of 82Kr
Populated by 82Br Decay [1].”
“Decay of 144Pr to Levels in 144Nd”, Nucl. Phys.
A 107, 402 (1968)
“The Decay of 142Pr to 142Ce and 142Nd”, Nucl. Phys.
A 113, 603 (1968)
“The Decay of 144Pm and the Energy Levels in
144
Nd”, Nucl. Phys. A 117, 407 (1968)
A = 142, A = 143, A = 144, Nuclear Data Sheets
(1967-1968)
“Decay of 67Cu”, Nucl. Phys. A 131, 393, (1969)
“A Note on 60Co Decay”, Z. Physik 228, (1969)
“Spin and Parity Assignment for the 872-keV Level
in 69Ga”, Phys. Rev. C 1, 744 (1970)
“Spectroscopy of 65,67,69Ga by the (d,n) Reaction”,
Phys. Rev. C 2, 149 (1970)
A = 60, A = 69, A = 58, Nuclear Data Sheets
(1968-1970)
RAMAN AND NUCLEAR DATA
As noted above, Raman began his professional
career in the Nuclear Data Project where he carried
out mass-chain evaluations. In addition to the mass
chain evaluation work, Raman realized early in his
career the power of “horizontal” compilations of
nuclear properties across a broad range of nuclei.
From these horizontal compilations he gained very
broad insight into nuclear structure physics that
would guide his entire career. He spent ten years
with the Nuclear Data Project (NDP) and, during this
time published 22 mass chain and horizontal
22
highly cited contributor to ADNDT. The first of his
eight contributions to ADNDT was published in
1975. Thus, in many ways Raman left important and
unique fingerprints on the journal, helping to
maintain its high standards and to fuel its growth and
breadth of impact.
Assigning the correct spin and parity value to a
nuclear level is a major aim of nuclear spectroscopy.
One of the most commonly used and most powerful
of the techniques for these assignments is the use of
log ft values. In the early 1970s, Raman made a
series of careful measurements to establish reliably
the lowest log ft value for a beta transition of a
particular forbidden type. These measurements led to
his most cited paper, “Rules for Spin and Parity
Assignments Based on Log ft Values [3],” published
in 1973. These rules have been invoked explicitly in
over 300 decay scheme studies and implicitly in
several hundred more. Raman’s interest in beta decay
continued with the publication of two major
compilations: one on super allowed 0+ - 0+ and
isospin forbidden transitions in 1975 and another on
mixed Fermi and Gamow-Teller beta transitions and
isoscalar magnetic moments in 1978. He pursued the
experimental study of superallowed 0+ - 0+
transitions, studying in detail four of the twelve cases
that are presently well established.
RAMAN AND RESEARCH
Raman was an extremely productive researcher.
His research legacy includes: 225 journal articles or
book segments, 125 published proceedings from
invited talks, and 55 published abstracts for a total of
~400 published works. He provided 150 seminars
during his career. The statistic that provides the most
insight into the importance of his work is the 3,750
citations to his work. Raman established definitive
decay schemes for about 35 radionuclides, most of
them for the first time, and discovered two new
isotopes, 48K and 45Ar. He was named a Fellow of
the American Physics Society in 1977.
Raman’s interest and involvement in data
compilations and evaluations has received worldwide
recognition including membership from 1983-1987
on the Panel on Basic Nuclear Data Compilations of
the National Research Council, National Academy of
Sciences. He had a long and influential role with the
journal Atomic Data and Nuclear Data Tables
reflecting his interests and contributions to nuclear
and atomic physics. His relationship with the journal
dates back to his initial position with
the ORNL Nuclear Data Project when he worked
with Katharine Way, the founding editor of Atomic
Data and Nuclear Data Tables. He served as
consulting editor of ADNDT beginning in 1983 and
became co-editor in 2001. Raman influenced the
journal greatly through his extensive international
collaborations and relationships in Japan, the former
Soviet Union, India, and other countries. These
collaborations brought new authors and new readers
to ADNDT. Raman and other leaders of the journal
realized early on that the world-wide-web would
particularly influence a journal such as ADNDT that
was devoted to compilations of high quality data in
extensive tabular and graphical form. ADNDT began
posting plain text, computer readable versions of the
tables on the web enabling readers to directly
download them. This opened the possibility that
these tables could be easily incorporated in computer
codes and processed electronically. Always attentive
to detail and clarity of presentation, Raman also lead
the way at ADNDT to introduce a formatted LaTex
template to facilitate the work of authors publishing
in the particular style that was the hallmark of the
journal. He, along with his collaborators, was also a
In 1975, Raman moved from the Nuclear Data
Project to the research staff of the ORELA, where he
initiated a program of neutron capture gamma-ray
spectroscopy that would significantly influence an
entire subfield of nuclear physics. He carried out
precise measurements (both at Oak Ridge and Los
Alamos) on a large number of nuclei, and developed
an advanced theory of direct capture to interpret the
observations. His publication of thermal neutron
capture on the sulfur isotopes [4] is one of his most
cited publications and an excellent example of his
attention to precision measurements and detailed
decay scheme construction. Raman’s work on the 1+
states in 208Pb [5] was particularly significant and led
to a large number of invited talks. This work was
also an avenue that brought him to the field of
electron scattering in which he made important
contributions.
While many are aware of Raman’s seminal work
in evaluations and in neutron capture, the full breadth
of his research is not generally known. Raman
published in all of the areas listed below. This
extensive list clearly shows his interest in all areas of
nuclear structure and reactions.
•
•
•
•
•
23
Nuclear Structure from Decay and
Reactions
Neutron Capture
Fission Cross Sections
Actinide Burning
Coulomb Excitation
•
•
•
•
•
•
•
•
Giant Resonances
Superheavy Elements
Heavy Ion Elastic Scattering
Heavy Ion Fragmentation
High Spin States
s-Process Nucleosynthesis
Accelerator Mass Spectroscopy
Neutron Oscillations
His research work also included significant
contributions to atomic physics that began with his
paper, “How Good are the Theoretical Internal
Conversion Coefficients? [6],” in which he showed
that the relativistic Hartree-Fock-Slater internal
conversion coefficients are systematically in error by
2-3%.
In 1976, a claim was made concerning the
discovery of primordial superheavy elements [7], a
claim of great significance if correct. The claim was
based on the observation of giant halos in mica
thought to have arisen from 14-MeV alpha particles.
As the initial paper was authored from ORNL, the
Laboratory assigned the job of verifying the
correctness to a team of staff members including
Raman. This team carried out extremely careful and
extensive measurements [8] at Stanford using
synchrotron radiation to excite x-ray spectra from the
same mica pieces that were used in [7]. Raman’s
team did not confirm the initial results, thus ending
the giant halo saga. Even though the Stanford
experiment failed to confirm the existence of
primordial superheavy elements, the analytical
method pioneered by the team – use of synchrotron
radiation for ultra-sensitive trace-element analysis –
is in widespread use today.
FIGURE 2. B(E2) adopted values (black dots) [9]; B(E2)
predicted values (black curve) [9]; new data (blue dots)
using radioactive ion beams at HRIBF [10].
Advisory Group meeting on Transactinium Isotope
Nuclear Data. That talk clearly defined and directly
influenced many of the activities worldwide
concerning the physics aspects of actinide waste
recycling. Subsequently Raman initiated the US/UK
Actinides Program (1979-1992) and the Japan/US
Actinides program (1988-present). Those programs
involved several ORNL divisions and brought into
the laboratory over $5 million. Scientific efforts for
the joint JAERI-ORNL program over the years of its
existence have been multi-faceted but have focused
on fundamental actinide chemistry applicable to
different technological applications. The program
was concerned with developing and establishing
selected thermophysical properties, as well as
advancing technological and fundamental aspects of
actinide science. The emphasis was placed on
chemical and physical properties, acquiring data
suitable for developing phase diagrams and/or other
databases, and for performing solid state-materials
science of these materials. The actinide programs
initiated by Raman provide an outstanding example
of collaboration between nations on major scientific
problems. This research effort was without a doubt
one of Raman’s favorite programs. He made many
visits to Japan and made many close friendships. Dr.
Mizumoto discusses this program in another paper in
the Proceedings.
In the last 15 years, Raman became particularly
interested in the systematics of quadrupole
distortions in nuclei. This began with his compilation
of B(E2) values for all even-even nuclei [9], and was
followed by a series of papers developing the
systematics and theory of collective behavior in these
nuclei. Figure 2 shows for tellurium and tin isotopes
the adopted values (black dots) from Raman’s
compilation along with the prediction (solid line) for
the B(E2; 0+ -2+) (e2b2) for unmeasured isotopes. The
colored points are results from recent measurements
[10] at the ORNL Physics Division Holifield
Radioactive Ion Beam Facility using radioactive ion
beams of Te and Sn nuclei.
Raman also joined the astrophysics research
program at ORELA. He was part of the group that
won the ORNL “Outstanding Publication Award” in
1997 for work on the 7Li(n, gamma) reaction [11].
This reaction is important for understanding the
production of 7Li in the big bang. It is also the mirror
At ORELA, Raman also undertook fission crosssection measurements of the higher actinides. In
1975, he delivered the keynote address at an IAEA
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reaction to 7Be(p,γ)8B, so it is relevant for
extrapolations of the 7Be(p,γ) cross-section to solar
energies for what was then called “the solar neutrino
problem.” There was a disagreement between
measurements of about a factor of two, and there
were no measurements below En=100 keV, except
for thermal. The ORELA experiment spanned much
of the energy gap between eV-keV and resolved the
discrepancy over the normalization of the cross
section. The citation reads “For research addressing
crucial astrophysical puzzles in the early universe
and in the core of our sun.”
FIGURE 4. Excitation function for 12C + 12C reaction with
double folding model calculation [12].
I was reminded of one of Raman’s most
interesting research efforts during a trip my wife and
I recently made to Arches National Park in Moab,
UT. What reminded me is shown in Figure 3. In case
you do not recognize it, this is a picture of the
“Parade of Elephants.”
FIGURE 5. Raman’s theoretical calculation for the data in
[12].
FIGURE 6. Raman’s theoretical prediction for the higher
energy data [12].
FIGURE 3. Photograph by the author of the “Parade of
Elephants” in Arches National Park near Moab, UT.
Needless to say the fits were made using Indian
Elephants [13].
In 1979, Raman was involved in an experiment to
measure the elastic and inelastic scattering of 12C by
12
C [12] using the heavy ion beams from the ORNL
Holifield Heavy Ion Research Facility. The
experimental results from those measurements show
excellent agreement with a double-folding model
calculation by Satchler [12] as shown on Fig. 4.
An important aspect to Raman’s research career
was the extensive international collaborations he
established. He valued his collaborators not only for
their scientific contribution, but also especially for
their friendship. In only the last ten years of his
research career, Raman had 65 non-US visitors or
collaborators from 23 different countries work with
him at ORNL. This says as much about Raman as
does his outstanding publication record. We can use
his example of collaboration and friendship as a
model for our own work with our worldwide
colleagues.
However, Raman had his own theoretical ideas
and carried out his own calculation. His much better
fit to the data is shown in Fig. 5.
Not finished yet, Raman even made a prediction
for the next generation measurement as seen on
Fig. 6.
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CONCLUDING REMARKS
REFERENCES
Subramanian Raman had an outstanding career as
a Nuclear Physicist. He is remembered especially for
his detailed and careful preparation of horizontal
evaluations of nuclear properties. He was a credit to
the Oak Ridge National Laboratory and to the
Physics Division of which he was a Senior Staff
Member. We will all remember him for his integrity,
his careful analysis of data, his wit, his friendship,
and most of all for his devotion to his family. We
shall all miss him. His career should serve as an
example of not only excellent nuclear physics
research but should clearly point to the need for
critical evaluation and compilation of the research
results.
1. Raman, Subramanian, Nuclear Physics A 90, 508-522
(1967).
2. Bertrand, F. E., and Raman, S., Nuclear Data Sheets
B5, 487 (1971).
3. Raman, S., and Gove, N. B., Phys. Rev. C 7, 19952009 (1973).
4. Raman, S., Carlton, R. F., Wells, J. C., Jurney, E. T.,
and Lynn, J. E., Phys. Rev. C 32, 18-69 (1985).
5. Raman, S., Misumoto, M., and Macklin, R. L., Phys.
Rev. Lett. 40, 507 (1978).
6. Raman, S., Walkiewi, T. A., and Gunnink, R., Phys.
Rev. C 7, 2531-2535 (1973).
7. Gentry, R. V. et al., Phys. Rev. Lett. 37, 11 (1976).
8. Sparks, Jr., C. J., Raman, S., Yakel, H. L., Gentry, R.
V., and Krause, M. O., Phys. Rev. Lett. 38, 205-208
(1977).
9. Raman, S., Nestor, Jr., C. W., and Tikkanen, P.,
Atomic Data and Nuclear Data Tables 78, 1-128
(2001); Raman, S., Nestor, Jr., C. W., Kanane, S., and
Bhatt, K. H., Atomic Data and Nuclear Data Tables 42,
1-54, (1989); Raman, S., Nestor, Jr., C. W., and Bhatt,
K. H., Phys. Rev. C 37, 805-822 (1988).
10. Private Communication, Radford, David, Physics
Division, Oak Ridge National Laboratory.
11. Blackmon, J. C., Champagne, A. E., Dickens, J. K.,
Harvey, J. A., Hofstee, M. A., Kopecky, S., Larson, D.
C., Raman, S., Powell, D. C., and Smith, M. S., Phys.
Rev. C 54, 383-388 (1966).
12. Stockstad, R. G., Wieland, R. M., Satchler,
G. R., Fulmer, C. B., Hensley, D. C., Raman, S.,
Rickertsen, L. D., Snell, A. H., and Stelson, P. H.,
Phys. Rev. C 20, 655-669 (1979).
13. Raman submitted these pictures for inclusion in the
book, SCIENCE with a Smile, An anthology selected
by Robert L. Weber, Institute of Physics Publishing,
Bristol and Philadelphia (1992), p. 111.
ACKNOWLEDGMENTS
I would like to thank the several people who
provided comments on Raman’s career that I have
used in this manuscript: Jeff Blackmon, Woody
Gove, Dick Haire, Bill Nestor, David Schultz,
Grimes Slaughter, my wife Jeanne, and the Raman
Family.
This research was sponsored by the U.S.
Department of Energy under Contract No. DEAC05-00OR22725 with UT-Battelle, LLC.
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