# Canada’s bright future in subatomic physics

24 August 2010

Assured funding and a new facility provide opportunities for TRIUMF.

In this era of fiscal uncertainty, several key agencies in Canada have stepped up and made firm commitments to TRIUMF and the future of particle and nuclear physics in Canada. In March, TRIUMF’s five-year core operating budget was renewed at the level of C$222.3 million for the 2010–2015 period. Then, in mid-June, the final pieces of the funding puzzle were put into place for the launch of the new flagship Advanced Rare IsotopE Laboratory (ARIEL) facility at TRIUMF, when the Province of British Columbia announced its C$30.7 million investment, completing the C\$63 million package. The project includes a new, high-power, superconducting radio-frequency electron linear accelerator for isotope production.

As Canada’s national laboratory for particle and nuclear physics, TRIUMF is owned and operated by a consortium of 15 Canadian universities. Its core operating funds are supplied in five-year blocks by the federal Ministry of Industry through the National Research Council Canada. The previous five-year cycle ended on 31 March 2010; new funding for the laboratory for the 2010–2015 period was unveiled in March as part of the federal budget. The announcement completes a process of more than two years’ effort to secure the funding. This included both an international review by some of the world’s most accomplished scientists and an economic-impact study that analysed the direct, indirect and induced impacts on the provincial and federal economies of public spending at TRIUMF.

TRIUMF celebrated its 40th anniversary last year. Over the years it has evolved from covering only medium-energy nuclear physics to include high-energy physics, materials science, rare-isotope beam physics, accelerator science and technology, and most recently, nuclear medicine. TRIUMF regularly produces intense beams of exotic isotopes using proton beams of up to 50 kW extracted from the main 500 MeV cyclotron. These isotopes are produced and studied in the Isotope Separator and Accelerator (ISAC) facility, which includes an impressive suite of experiments and detectors for research in nuclear structure and nuclear astrophysics, and for tests of fundamental symmetries. TRIUMF recently completed an upgrade of the ISAC-II facility to provide acceleration of radioactive ions of up to 5 MeV/u. This linear accelerator was developed using superconducting radio-frequency cavities manufactured in Canada by PAVAC Industries in co-operation with TRIUMF. In nuclear medicine, TRIUMF has a 30-year history of producing medical isotopes using small cyclotrons in partnership with MDS Nordion for global sales and distribution.

### The five-year vision

The federal contribution for operations will not support all of the TRIUMF community’s aspirations (nor should it), but it does support and strengthen key initiatives in particle physics, nuclear physics, materials science, nuclear medicine and accelerator science and technology. In nuclear physics, the programme will focus on exploiting the existing ISAC-I and ISAC-II facilities. An aggressive programme in target development will continue and deliver beams of novel isotopes from actinide targets for physics experiments in the next 2–3 years. A programme for the production and characterization of uranium-carbide foils for use in ISAC has begun and the first physics run using novel isotopes from actinides is scheduled for December 2010.

In materials science, construction work on additional muon beamlines will be completed to offer greater flexibility and more time for scientific usage. A new initiative in nuclear medicine is being launched that expands TRIUMF’s historic activities in medical-isotope production into radiochemistry for the development and preclinical qualification of new radiotracers. The nuclear-medicine programme will include new equipment, full-time personnel and stronger partnerships across Canada.

In particle physics, the ATLAS Canada Tier-1 Data Centre will continue its operations; it serves as one of the 10 global data-storage and distribution centres for physics data from the ATLAS experiment at CERN’s LHC. Canada’s involvement in the Japan-based Tokai-to-Kamioka neutrino experiment will continue to receive support from TRIUMF as the research moves into the data-collection and analysis phase.

### ARIEL takes off

The ARIEL facility will be the new flagship of the TRIUMF programme, which includes a new underground beam tunnel surrounding a next-generation linear accelerator – the e-linac, a project led by the University of Victoria. This facility substantially expands TRIUMF’s isotope-production capabilities by adding the technique of photo-fission to the suite of available technologies. Canada will be unique in having electron- and proton-based capabilities for isotope production within the same laboratory. Moreover, for the first time in 35 years, TRIUMF’s main cyclotron will have a fully fledged younger sibling to drive the breadth of the laboratory’s research.

The lower floors of ARIEL will house the e-linac, which will produce an intense beam of electrons up to 50 MeV. An underground beam tunnel will connect the accelerator to the isotope-production area, where the beam of electrons will strike a convertor to create an intense beam of photons via bremsstrahlung. This beam will in turn be directed at targets made of beryllium, tantalum or actinide materials, for example. The isotopes will be extracted, separated and accelerated in real time and sent to the ISAC experimental areas.

The focus of ARIEL will be on “isotopes for physics and medicine”. In terms of nuclear physics with rare isotopes, ARIEL is expected to increase TRIUMF’s annual scientific productivity by a factor of 2–3 above current levels by providing a second primary “engine” for producing isotopes. ISAC will move from being a “one-at-a-time” facility to running several experiments simultaneously. The e-linac will expand the materials-science capabilities at TRIUMF by enabling high-volume production of lithium-8 for β-NMR studies using a beryllium target. In terms of isotopes for medicine, the facility is intended to develop and study next-generation medical isotopes that may have applications in therapy (e.g. via alpha emission). ARIEL will also be used to demonstrate and benchmark the use of photo-fission technology for larger-scale production of key medical isotopes that are currently only produced in reactors, such as 99Mo/99mTc. Photo-fission at ARIEL could produce at least one six-day Curie of 99Mo per gram of natural uranium target material for a 100 kW irradiation period.

Construction of the ARIEL facility and e-linac began on 1 July, providing immediate stimulus to the civil-construction and technical communities in British Columbia and Canada. The facility will be completed in 2013 and the e-linac will then be installed. Isotope production for physics and medicine will be commissioned in 2014 and round-the-clock operations will become routine in 2015. ARIEL is designed to support two target stations – one initially for electrons and a future one for a new proton beamline extracted from the main 500 MeV cyclotron.

The e-linac will begin with a 30 MeV, 100 kW beam by 2014, with plans for it to be upgraded to a full 500 kW beam in the 2015–2020 era. The superconducting radio-frequency technology selected for the accelerator expands an emerging core competency at TRIUMF in partnership with a local electron-beam welding company, PAVAC Industries. The e-linac will be built using 1.3 GHz technology, recognizing the global move to parameters similar to those of the TESLA and International Linear Collider projects. The injector cryomodule is being designed and constructed in collaboration with India’s Variable Energy Cyclotron Centre in Kolkata.

With a broad set of opportunities and programmes facing it, TRIUMF is optimistic about the next decade of scientific activity. Together with its national and international partners, the laboratory hopes to bring a “gold medal” home to Canada in subatomic physics.