Reviews Of Accelerator Science And Technology - Volume 8: Accelerator Applications In Energy And Security

Volume 8: Accelerator Applications in Energy and Security

Alexander W Chao, Weiren Chou

• Publisher: WSPC
• Year: 2016
• eBook ISBN: 9789813108912
• Topic: Technology & Engineering
• Subtopic: Applied Sciences
• Index: Technology & Engineering

As accelerator science and technology progressed over the past several decades, the accelerators themselves have undergone major improvements in multiple performance factors: beam energy, beam power, and beam brightness. As a consequence, accelerators have found applications in a wide range of fields in our life and in our society. The current volume is dedicated to applications in energy and security, two of the most important and urgent topics in today's world.

This volume makes an effort to provide a review as complete and up to date as possible of this broad and challenging subject. It contains overviews on each of the two topics and a series of articles for in-depth discussions including heavy ion accelerator driven inertial fusion, linear accelerator-based ADS systems, circular accelerator-based ADS systems, accelerator-reactor interface, accelerators for fusion material testing, cargo inspection, proton radiography, compact neutron generators and detectors. It also has a review article on accelerator science and technology in Canada with a focus on the TRIUMF laboratory, and an article on the life of Bruno Touschek, a renowned accelerator physicist.

As accelerator science and technology progressed over the past several decades, the accelerators themselves have undergone major improvements in multiple performance factors: beam energy, beam power, and beam brightness. As a consequence, accelerators have found applications in a wide range of fields in our life and in our society. The current volume is dedicated to applications in energy and security, two of the most important and urgent topics in today's world.

This volume makes an effort to provide a review as complete and up to date as possible of this broad and challenging subject. It contains overviews on each of the two topics and a series of articles for in-depth discussions including heavy ion accelerator driven inertial fusion, linear accelerator-based ADS systems, circular accelerator-based ADS systems, accelerator-reactor interface, accelerators for fusion material testing, cargo inspection, proton radiography, compact neutron generators and detectors. It also has a review article on accelerator science and technology in Canada with a focus on the TRIUMF laboratory, and an article on the life of Bruno Touschek, a renowned accelerator physicist.

Readership: Physicists and engineers in accelerator science and industry.

Accelerator Science and Technology in Canada — From the Microtron to TRIUMF, Superconducting Cyclotrons and the Canadian Light Source

M. K. Craddock

Department of Physics and Astronomy,
University of British Columbia, and
TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
[email protected]

R. E. Laxdal

TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada
[email protected]

As elsewhere, accelerators in Canada have evolved from modest beginnings to major facilities such as TRIUMF (currently with the highest-power driver for rare isotope beam production) and the third generation Canadian Light Source. Highlights along the way include construction of the first microtron, the first racetrack microtron and the first superconducting cyclotron (to which list might have been added the first pulse stretcher ring, had it been funded sooner). This article will summarize the history of accelerators in Canada, documenting both the successes and the near-misses. Besides the research accelerators, a thriving commercial sector has developed, manufacturing small cyclotrons and linacs, beam line components and superconducting rf cavities.

Keywords: Canada; accelerator history; microtron; stretcher; superconducting cyclotron; AECL; TRIUMF; CLS.

1. Introduction — A Historical Survey

Canada received a very early introduction to nuclear science through Ernest Rutherford’s presence at McGill University in Montreal between 1898 and 1907, the period during which he unraveled the secrets of radioactivity, for which he was awarded the Nobel Prize in Chemistry. This inspired a steady stream of Canadian students to follow him back to Manchester and Cambridge for Ph.D.s [1] — conditions not yet being ripe for the development of strong nuclear research programs in Canadian universities. In the first place the funding available for academic research was minimal, and in the second only two universities, McGill and Toronto, offered Ph.D. programs [2] — obstacles that were only overcome following World War II.

The earliest Canadian attempt to accelerate a beam of particles began in 1937 at the University of Toronto, where Prebus and Hillier [3] started building what has been described as “the first practical electron microscope” — a 45 keV device that was also the first in North America. Not that higher energy machines for nuclear physics had been forgotten: late that same year McGill University approved funds for a large cyclotron — but the design was still being finalized in 1939 when Canada entered World War II, preventing any start to construction. Queen’s University in Kingston refused to issue funds for a cyclotron but approved a Van de Graaff in July 1939; however, that suffered the same fate.

As it turned out, these delays were probably fortuitous as the war changed everything for accelerators. Firstly, there were two major technical advances: the discovery of the phase stability principle and the development of rf equipment for radar (particularly for higher power and higher frequencies). But even more significant was the greater importance (and funding) that governments had been forced to accord to science. Nuclear science in particular, promising a new source of electric power, became the hottest discipline of the postwar years.

During the war, these factors led to a major expansion in the activities of Canada’s National Research Council (NRC) laboratories, particularly in radar and nuclear fission. Then, when in 1942 the British decided to move their Tube Alloys nuclear project to a safer location, it became a collaborative effort with Canada under the auspices of NRC. At first it was housed at l’Université de Montréal, but in 1944 the staff, which by then had grown to over 300, began moving to a new laboratory site at Chalk River, 180 km west of Ottawa.

Postwar, the NRC’s activities in other areas shrank somewhat, but its Physics Division nevertheless succeeded in building Canada’s first MeV particle accelerator, producing 4.6 MeV electrons in the world’s first microtron in 1947 [4–6].

1.1. Low-energy accelerators proliferate

NRC’s mandate to support university research was also strengthened through a much-expanded grant program and the provision of postdoctoral fellowships. In some cases funding was also obtained from the newly formed Atomic Energy Control Board (AECB). At the same time, more universities across the country began instituting Ph.D. programs. Together with the new popularity of nuclear physics, these factors led to the eventual construction of accelerators at most major universities. The first to come into operation (in 1948) was a 25 MeV betatron at the University of Saskatchewan (UoS), purchased from Allison-Chalmers. Next, in 1949, was the long-delayed cyclotron at McGill, now reconfigured with the rf modulated, thereby raising the proton energy dramatically to 100 MeV. This was followed in 1950 by Queen’s University’s 70 MeV electron synchrotron, built by General Electric. Then, in 1951 and 1952 respectively, the University of British Columbia (UBC) and Chalk River commissioned 3 MV Van de Graaffs based on an MIT design.

By 1955 there were dreams of much higher energies and, in 1958, after countrywide deliberations, the Canadian Association of Physicists submitted to the government a proposal for a 15 GeV proton synchrotron to be built at Queen’s. It was refused, as was a followup proposal by UBC for a less costly 7 GeV synchrotron.

The government’s refusal, however, had been accompanied by a promise to increase funding for nuclear research at universities. This led to a fresh wave of low-energy accelerator installations in the 1960s. The new machines were mostly commercial Van de Graaffs and tandems (in fact the very first tandem had been commissioned by Chalk River in 1958). But there were also two electron linacs [140 MeV at the UoS and 40 MeV at the University of Toronto (UoT)] and a 50 MeV H⁻ cyclotron at the University of Manitoba UoM]. In addition, the first racetrack microtrons were developed at the University of Western Ontario (UWO), reaching 6.3 MeV in 1960 and 15 MeV in 1967.

1.2. Development of major facilities

1.2.1. 1960s and ’70s

In the early 1960s, Chalk River [which had split from NRC in 1952 as Atomic Energy of Canada Ltd. (AECL)] began a serious study of electronuclear breeding. This led to a proposal for an Intense Neutron Generator (ING) requiring a 65 mA proton beam at 1 GeV. At first the design was based on separated-orbit cyclotrons (SOCs) but in 1966 it was changed to a linac. The proposal was turned down two years later, though R&D on high-current sources and linacs continued for many years.

Around the same time, a group of universities in western Canada developed the TRIUMF proposal for a meson factory, to be based on a 500 MeV, 100 μA H⁻ cyclotron. This was approved in 1968 and came into operation in 1974.

At the Saskatchewan Accelerator Laboratory (SAL), the electron linac was upgraded to 220 MeV in 1975 and to 300 MeV in 1980. A pulse stretcher ring had been proposed in the early 1970s and, if funded in a timely manner rather than in 1983, would have been the first to be built. The Electron Ring of Saskatchewan, or EROS (locally designed and built), was commissioned in 1987.

At Chalk River the original 6 MV EN tandem from HVEC had been replaced by the HVEC MP unit in 1967, later upgraded to 15 MV. To achieve even higher-energy heavy-ion beams, a novel concept was proposed — the addition of a K500 superconducting cyclotron, whose high-field magnet would permit a very compact and inexpensive design. Though it was the first to be conceived (in 1973) and started, management caution, funding problems and the complication of injecting from a preaccelerator slowed progress and it was only the second to come into operation (in 1985). In 1974 AECL staff also patented a design for a 25 MeV superconducting deuteron cyclotron small enough to be mounted on a gantry for neutron therapy (later built under license by Michigan State University in a 50 MeV version and run for many years at Harper Hospital, Detroit).

None of these developments benefitted Canadian particle physicists, and in the late 1970s, seeing no prospect of the government’s funding a green-field high-energy accelerator, they collaborated countrywide on developing a proposal (in 1980) for a Canadian High Energy Electron Ring (CHEER) to be built at either Fermilab or Brookhaven. This 10 GeV synchrotron would have enabled e–p collisions to be studied for the first time. It was not funded. But a $7 million^a accelerator contribution was later made to the HERA e–p collider in Hamburg — rf cavities from Chalk River and a 50 MeV H⁻ ion transfer line from TRIUMF.

1.2.2. 1980s and ’90s

In 1979 the Alberta Provincial Cancer Hospitals Board contracted DSMA Atcon Ltd. to recommend a heavy-ion medical facility for both therapy and isotope production. Their proposal, strongly influenced by one from LBL, was for a 415 MeV/u C⁶⁺ synchrotron together with two low-energy cyclotrons [7]. The Alberta government then funded a feasibility study for the design of a Medical Accelerator Research Institute in Alberta (MARIA). The resulting MARIA Design Symposium [8] recommended a 1 GeV/u synchrotron similar to Saturne-II with a K140 cyclotron injector. Unfortunately, oil prices (and the province’s revenues) collapsed in 1981 and it canceled the project.

In 1981 l’Université de Montréal combined with UoS in proposing a 1 GeV continuous wave (cw) racetrack micr...

Table of contents

• Cover
• Halftitle
• Title Page
• Copyright
• Editorial Preface
• Contents
• Overview of Accelerator Applications in Energy
• Overview of Accelerator Applications for Security and Defense
• Heavy Ion Accelerator–Driven Inertial Fusion
• ADS Based on Linear Accelerators
• Cyclotrons and FFAG Accelerators as Drivers for ADS
• Accelerator–Reactor Coupling for Energy Production in Advanced Nuclear Fuel Cycles
• Accelerators for Fusion Materials Testing
• Low Energy Accelerators for Cargo Inspection
• Flash Proton Radiography
• Compact Neutron Sources for Energy and Security
• Detectors for Accelerator-Based Security Applications
• Accelerator Science and Technology in Canada — From the Microtron to TRIUMF, Superconducting Cyclotrons and the Canadian Light Source
• Bruno Touschek: From Betatrons to Electron–Positron Colliders