User:Theophilus Reed/sandbox/Columbia Cyclotron

The Columbia cyclotron, or Columbia atom smasher, was an early particle accelerator housed in the basement of Pupin Hall at Columbia University in New York City. It was associated with early investigations into atomic energy, especially those conducted by Enrico Fermi, Leo Szilárd, Isidor Isaac Rabi, Willis Lamb, Herbert L. Anderson, John R. Dunning, and a number of other pioneering nuclear physicists.

On 25 January 1939, an especially important experiment investigating the nuclear fission of uranium was performed using the apparatus; this effort confirmed the original discovery of fission by the German team of Otto Hahn and Fritz Strassmann from just a few weeks prior. This result, along with other research performed over the following months using the Columbia instrument, strongly suggested the possibility of a nuclear chain reaction, which until that time was a wholly theoretical hypothesis. These experiments were critical in efforts to gain scientific and political support for the creation of the Manhattan Project during an early phase of World War II.

Background
The Columbia apparatus was capable of accelerating protons, deuterons and alpha particles to energies in the range of tens of MeV; it operated from 1938 to 1964. Based upon earlier designs by Ernest Lawrence of the University of California, Berkeley, this cyclotron was built by the pioneering nuclear physicist John R. Dunning, largely from parts salvaged from older industrial facilities.

Federal Telegraph Company (1909-1928) described as Silicon Valley's "first major high-tech company"; 350kw arc transmitter 60 tons

p. 129-130 We are familiar with Federal's growth under navy contracts, and with the culmination of their relations in commissioning four 1000-kW generators, two for each end of a radio link between the United States and its expeditionary force in France. Their magnets could deliver 18,000 gauss.. The war ended before the huge antenna towers...could be complete in France. The navy withdrew. leaving France with half a radio station and Federal with four 80-ton magnets... that left Federal with two war-surplus magnets... p. 130. "Lawrence's big magnet, being a piece of high technology, required professional engineering help in its metamorphosis into a tool of science... Cattell wound and insulated the coils at Federal before the magnet went to Pelton for machining... Pelton did an excellent job, the pole faces parallel to four-thousands of an inch, the field homogenous up to 18 kG."

Confirmation of Fission Discovery
The experiment devised aimed at studying the ionization, or electrical pulses, that would be released after uranium atoms had been split. These pulses were to be watched on an oscilloscope, which has been described "as a species of atomic thermometer."! The energy, or pulses, is transformed into lines on an oscilloscope and can thus be observed. On the day of the experiments, Fermi had to go to Washington and Dr. John R. Dunning, with some colleagues, carried out the investigation.

Outside, a cold wind raced through the campus as Dunning and Drs. E. T. Booth and F.G. Slack prepared for the experiment. After laborious efforts in readying the cyclotron, all was ready for the attempt to split the uranium atom. Then the bombardment began, and

"Suddenly, huge green lines began to shoot up in the circle of the oscilloscope screen. They leaped high and seemed to jump from the screen and they stunned the scientists. .... He'd [Dunning] never seen anything like it before. He quickly calculated that between 150 and 200 million electron volts were being generated. At that rate one pound of Uranium-235 could yield as much energy as 5 million pounds of coal."

Afraid that something might have gone wrong, Dunning carefully checked the cyclotron and other apparatus, but found nothing amiss. He then repeated the experiment many times and by about midnight was convinced that atomic energy could be released.

Decommissioning & Demolition
Because of the significance of discoveries made using this instrument, the Pupin Physics Laboratories were designated a National Historic Landmark in 1965. Contemporaneously, the instrument was decommissioned, and the core part of the device — the 'double-dee' vacuum chamber where particles were accelerated along with important detector equipment — was donated to the Smithsonian Institution.

In 2007, Columbia University administrators announced plans to junk what remained of the 65-ton apparatus, in order to free-up space for future expansion. Despite vehement protests from faculty, students, and historic preservationists, in 2008, this renowned 'gadget' from the Atomic Age was cut-up and its metal sold for scrap. This was to save an estimated additional expense of approximately $90k to dismantle and store this massive component of the historic instrument.

However, it should be noted that the scrapped machinery was largely the circa-1918, war-surplus, former Poulsen-arc transmitter electromagnet, while the much smaller accelerator/detector components that discovered 'new physics' have mostly been preserved at the Smithsonian. A very similar war-surplus, Poulsen-arc electromagnet that was part of Ernest O. Lawrence's 37" cyclotron remains on display on the campus of the University of California, Berkeley.