Press coverage of the Society and its activities

Remembering ING

Written by
Jim Ungrin
for
the North Renfrew Times
2022 Oct 05

In a recent article in the North Renfrew Times (Sep 21, 2022), D. Winfield described a visit to the European Spallation Source (ESS) located in Sweden. The ESS, the next “BIG Science Facility” is based on a proton accelerator and, with 2 megawatt (MW) of beam power, will be ”the most powerful linear proton accelerator ever built.” This story brings back memories of the Canadian Intense Neutron Generator (ING) proposal of the 1960s.

The story starts in the early 1960s – the period of glory for neutron and nuclear research at Chalk River. NRX had been a great success for over a decade. It was followed by another outstanding success, NRU, which increased neutron flux for many important basic and applied research applications. What was next in this chain of increasing flux?

The proposal, championed by W.B. Lewis, was for ING – an accelerator-based neutron source that would further increase the available neutron flux by another order of magnitude. The proposal was based on the so-called spallation process whereby one high energy (1-2 GeV) proton “spalls” or knocks off 30-40 neutrons from a nucleus in a heavy-metal target (lead or bismuth) when it strikes it. The design narrowed to an accelerator that would be about a1.6 km in length, have an energy of 1 GeV and a beam power of 65 MW – thirteen times greater that of the ESS. In addition, a lower-power, high-energy beam would be accelerated simultaneously for meson research.

ING would have produced a jump of about three orders of magnitude in power over existing proton accelerators. The proposed location would be Chalk River.

As the ING proposal gained traction at Chalk River, the amount of design and research effort on accelerators, liquid bismuth targets, radio-frequency (rf) power supplies, and experimental facilities ramped up very quickly. By mid-1966 almost 40% of Chalk River’s research effort was on the ING project.

About this time concerns began to surface within the entire Canadian research community regarding the impact ING capital costs would have on their programs. Opposition to the project formed at a number of universities. This caused a shift in thinking as to siting of ING. Perhaps a location nearer airports and universities might be more palatable to the research community. Alas, this was not to be the case, and in spite of a siting change and a positive recommendation for further funding of the project by the Science Council In early 1967, the project was cancelled in September 1968 by the new Trudeau government because of its “very high costs”.

Had the project not been cancelled, would it have led to the projected success and international co-operation projected now at the ESS? That is a debateable question. Huge jumps in accelerator technology in areas of ion sources, beam dynamics and rf supplies would have been needed for ING to be a technical success. Some of these technology jumps have not been fully achieved even 50 years later.