Linear Accelerator Puts SC Into Nuclear Research

Reprinted from the January 1958 Alumni Review

Physicists from all over the world were taking a coffee break during the annual winter meeting of the American Physical Society held on the SC campus in December, 1955. Dr. Ernest O. Lawrence, head of the physics department at the U of California at Berkeley, was chatting in a Founders Hall corridor with Dr. Gerhard L. Weissler, then head of the SC physics department. The two scientists were discussing a linear accelerator, one of the many pieces of nuclear equipment in the vast physics laboratories on the northern campus.

Dr. Lawrence turned to his colleague and asked: "Would you like to have this machine on your campus?"

Surprised and delighted, the younger man said of course he would and as casually as that the wheels were set in motion for the transfer of more than two million dollars worth of nuclear research equipment from Berkeley to the Trojan campus. With Dr. Lawrence's generous support, the Atomic Energy Commission was persuaded to turn the equipment over to SC, along with an annual operating grant of some $200,000.

Last November 25, ground was broken for the building to house the new equipment, which is expected to be installed and working some time in the spring of 1959. The building itself will be completed about May 1.

No Strings Attached

No strings were attached to the gift. SC scientists have free rein to perform any experiments they choose with the equipment and the research to be carried on in the new Nuclear Physics Laboratory is, in a sense, limitless. Basic research, of course, is distinguished from what is often miscalled practical research by its freedom from specific objectives. But findings of the basic researcher ultimately become the property and tool of the specific researcher.

Typical of the information to be sought, however, will be hitherto unknown information on the dimensions of the nuclei of various elements, data obtained from nuclear transmutations (operations by which one element may be changed into another), and information about the energy levels of nuclei.

To house the new equipment, the University is erecting a 144- by 70-foot reinforced masonry and concrete building to cost $175,000. It will be a one-story structure 23 feet high, resting on a heavy concrete slab. It is rising on Hoover St., west of the Science Bldg., where it will be part of what will ultimately be a Science Quadrangle.

Inside this building, and shielding the scientists and their elaborate recording instruments from the accelerator and its generator, will be another 3-foot concrete shell. This will have moveable walls, so that cranes can get at the generator and accelerator when maintenance tasks require them to be lifted.

A 32-million Volt Bombardment

The new equipment to be housed in this shell will include two major pieces. The first of these is a Van de Graaff generator, which takes hydrogen protons at rest and speeds them up to an energy of four million electron volts. At this point, the protons pass into the linear accelerator and are speeded by successive electrical charges to 32 million volts (roughly equivalent to a speed of 50,000 miles per second.)

At this speed, the protons will bombard whatever target element is placed at the end of the linear accelerator. The effects of this proton bombardment on the target element will give the scientists data of various kinds about the nuclear structure of that element.

The Van de Graaff generator is a long, insulating tube of porcelain inside a 20-ton steel shell about 30 feet long by some 10 feet in diameter. The porcelain tube is surrounded by nitrogen under 200 pounds pressure per square inch by way of insulation. The porcelain tube itself contains a vacuum. When gaseous hydrogen is admitted into one end of this tube, and subjected to an electrical discharge, its protons separate and are shot through the vacuum tube into the linear accelerator attached to the other end of the generator.

In the linear accelerator, the protons pass through a series of tubes in a near vacuum. At each gap between the tubes the energy of the protons shot through the tubes is stepped up electrically until it reached its maximum of 32,000,000-volts.

Prof. Weissler's Background

Professor Weissler, who will direct the nuclear research and have the title of chief investigator, is a naturalized American who fled from the Hitler terror in 1939 after his uncle had been beaten to death in a Nazi concentration camp for his support of Protestant Pastor Niemoeller and after Weissler himself had been expelled from a Berlin university for protesting Nazi atrocities he had witnessed. He enrolled at UC Berkeley as a graduate student in physics, obtaining his Ph.D. there in 1942. He was an instructor in radiology at the UC Medical School when SC's President von KleinSmid and Vice President Raubenheimer invited him onto the SC faculty as an assistant professor. In 1951 he was appointed head of the Physics Dept. In 1956 he asked to be relieved of his academic administrative responsibilities in order to direct the transfer and installation of the new equipment on the SC campus. He was succeeded as department head by Dr. John R. Holmes.

Dr. Weissler is married to an LA girl by whom he has a son, aged 3. They expect another child any day. They live in Baldwin Hills near the Trojan faculty tract where Coach Don Clark has built his home.

A First Step

Under the new set-up, Dr. Holmes will function as deputy chief investigator. He also expects to add two or three faculty members to the Physics Dept. to assist with the nuclear experiments.

Both Weissler and Homes regard installation of the linear accelerator as the first step in a long-range, expanded program of nuclear research. Dr. Homes told REVIEW he expects the new installation to improve the SC graduate program in physics. This, in turn, should attract more of the best science students, since undergraduate teaching is done by graduate students serving as teaching assistants.

Said Holmes: "SC is bound to become an even better teaching institution as we expand our work in basic research."

Anthony D. Lazzaro `49, SC director of physical plants, was the liaison between the Physics Dept. and the architects and builders.

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