Nobel Prize Winner

Dr. Owen Chamberlain '41 Shares Award in Physics with California Colleague

ON the morning of October 26, the winners of the 1959 Nobel Prize in physics were announced by the Academy of Sciences in Stockholm, Sweden. Named as co-recipients of the honor were Professors Owen Chamberlain '41 and Emilio Segre, both of the University of California at Berkeley.

The two scientists Won the coveted international prize for their discovery, in 1955, of the anti-proton, a negatively charged fundamental particle of matter. The 17th and 18th Americans to win the Nobel award for physics, they will share a prize of $42,600.

Such are the bare facts of human achievement.

That afternoon, in Cambridge, Massachusetts, Dr. Owen Chamberlain walked into a lecture room at Jefferson Laboratory to the applause of 300 Harvard faculty men and women and graduate students. (He is Morris Loeb Professor of Physics during the fall term.) His lecture was regularly scheduled, but word had got around of his distinguished honor, and the room was packed. He was introduced by the chairman of the Harvard Physics Department, Dr. Jabez Curry Street, who observed with calm understatement, "The selection of a speaker this afternoon was very timely."

With a half apologetic request that they forgive "a few comments on the new honor that has come my way," the Nobel Laureate told his applauding audience, "I don't feel we've done anything exceptional. I feel I could nominate many other at least equally worthy candidates." He went on to credit fellow researchers, Drs. Clyde Wiegand and Tom Ypsilantis as coauthors with Dr. Segre and himself of the paper announcing the discovery of the anti-proton in 1955. Referring again to the Nobel Prize, Professor Chamberlain said, "It just has to be looked at as a vote of confidence in the whole program of high energy physics."

With that the professor laid his pipe on top of his notes and began his regular lecture.

The particle of anti-matter which earned world acclaim for Dr. Chamberlain and his colleague is an elusive nuclear ghost that has haunted scientists for more than a quarter of a century.

One of the twenty-odd fundamental particles of nature, the anti-proton, sometimes called the negative proton, was the missing link which challenged a generally accepted concept of the basic symmetry of nature, that every positively charged particle of an atom has its negative counterpart. This conception of matter originated with the English physicist, P. A. M. Dirac, in 1928, and was partially confirmed in 1932, Prof. Carl D. Anderson of the California Institute of Technology discovered the positron, or anti-electron.

Paradoxically, the ghostly anti-proton was finally materialized by Dr. Chamberlain and his colleagues in the world's largest atom-smasher, the giant Bevatron at the Radiation Laboratory of the University of California. Constructed by the Atomic Energy Commission at a cost of $9,500,000, the Bevatron is a high-energy accelerator capable of accelerating positive protons, the nuclei of hydrogen atoms, to energies of 6.2 billion electron volts by whirling them around a 400-foot circular track. To create the anti-proton, which does not exist in nuclei, the speeded-up protons are bombarded against a copper target inside the Bevatron chamber. The collision with neutrons of the copper atoms creates a new pair of protons, one negative and one positive.

The negative or anti-protons are then diverted through a kind of magnetic maze into a separate beam. But they are brieflived. When they collide with positivelycharged matter - protons or neutrons - total annihilation results. This cosmic catastrophe manifests itself in the transmutation of matter into the enormous energy of nearly two billion electron volts.

Part of the difficulty which faced the scientists in identifying the anti-proton after its creation was to find it in the background of a large mass of particles. According to Dr. Chamberlain, it was a question of sifting out one anti-proton for each 30-50,000 other particles.

Conclusive confirmation that the "nuclear ghost" had been materialized was obtained in December 1955, with the first visual observation of the anti-proton's action on matter. This was achieved by means of highly sensitive photographic emulsions in which the anti-proton collided with a positive proton in the nucleus of the silver or bromine atoms in the emulsion. In that collision, a cosmic flash that lasted only 100 sextillionths of a second, the anti-proton left its track in the form of a tiny star-like mark on the photographic emulsion. This mark was the cosmic debris left in the wake of the nuclear explosion.

Discovery of the anti-proton led shortly to the anti-neutron and completed confirmation of the concept of "mirror image" counterparts of all charged nuclear particles so far observed. (They exist in three electrical forms, positive, negative and neutral.)

Owen Chamberlain, Dartmouth's first Nobel Laureate, was born in San Francisco in 1920 and moved to Philadelphia at the age of 10, when his father became professor of radiology at Temple University Medical School. He attended the Germantown Friends School in Germantown, Pa., and there became known as a brilliant science student. Comments in the 1937 yearbook of the school are revealing of his future: "We have yet to find the physics problem that will stump Owen. . . . Just ask Professor Birdlegs to explain the principle behind a coherer, or merely mention the electrostatic forces, then settle yourself in a comfortable armchair for an interesting hour."

In 1941 "Professor Birdlegs" was graduated magna cum laude from Dartmouth with highest distinction in his major, physics. As an undergraduate, he was vice president of Germania and a member of Theta Chi. He won the Thayer Mathematics Prize in 1939 and the Haseltine Physics Prize in 1941- He was also awarded a $1,000 R. Melville Cramer Fellowship for graduate study at the University of California. After a year's work there, he joined the Manhattan District Project that developed the atomic bomb during World War II.

Following the war, Dr. Chamberlain went to the University of Chicago to study with the late Dr. Enrico Fermi, the renowned Italian physicist who produced the first atomic chain reaction, and who suggested the work topic for his doctoral thesis. In 1948 he received his Ph.D. degree and returned to the University of California as an instructor. In 1958 he became a full professor. He was awarded a Guggenheim Fellowship in 1957 and spent the following year in Rome, where "I was trying to catch up on my book work. When you are in the middle of experiments, it is easy to neglect some of the more intellectual pursuits."

Professor Chamberlain is a fellow of the American Physical Society and national secretary of the Federation of American Scientists. He was married to Babette Copper in 1943, and they have four children, Karen, 13, Darol, 10, Lynn, 9, and Pia, 20 months. The family lives at 6 Martha's Point Rd., Concord, Mass., and will return to Berkeley in February.

Dr. Chamberlain Being Interviewed at Harvard.