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In search of the
Nigel Lockyer
Director of TRIUMF
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Particle and nuclear physics research is leading to greater understanding about the origins and
structure of matter, providing significant implications for science, medicine and beyond. Nigel
Lockyer offers fascinating insights into TRIUMF’s study of the Higgs boson, as well as its work
on rare isotopes which could offer hope to patients with cancer and Parkinson’s disease.
As an introduction to your research facility, could you outline the
experimental focus of TRIUMF – Canada’s National Laboratory for
Particle and Nuclear Physics?
From a science perspective, TRIUMF’s focus is to address some of the
most compelling questions in research with programmes of scientific
experiments. Scientists pose questions and then try to answer the ones
they know how to attack. As a physics laboratory, we are most interested
in the origins and structure of matter (eg. the recent discovery of the
Higgs boson in which we were heavily involved) and the study of isotopes
for science and medicine – perhaps what we are best known for in Canada
and around the world.
There are some outstanding research facilities at TRIUMF. Can you
give an insight into the kind of instruments that are in use at the
laboratory? What makes them unique?
First of all, TRIUMF is an accelerator laboratory. All of our activities
start with an accelerator or related technologies in some shape or
form. Accelerators are used to make beams of high-energy charged
particles – like a proton beam, for example. We have five different
types of accelerators on site, ranging from the world’s largest
cyclotron to a superconducting heavy-ion linear accelerator to a small
medical cyclotron used to produce medical isotopes primarily for
neurodegenerative diseases like Parkinson’s disease and cancer research.
The main cyclotron is used to make intense beams of isotopes for study
of nuclear structure and nuclear astrophysics. The various beams we
make allow us to study the precise make up and microscopic behaviour of
unstable isotopes and even discover new ones. Coupled with this system
of accelerators are a suite of particle detectors that allow us to track,
identify, and in some cases manipulate the particles to understand their
properties and even their internal structure. It is the combination of these
tools that helps make TRIUMF unique.
The Linear Collider Collaboration is a newly formed collaboration
relationship between the International Linear Collider (ILC) and
the Compact Linear Collider (CLIC). What is the purpose of this
joint venture and why are you working on it together? How does it
complement the work conducted at CERN?
As you state, there are two technical approaches to building the 30km
linear accelerator. The technologies overlap and so there are synergies
between the competing teams. They recognise they can make faster
progress by working together. The ILC uses superconducting (zero
resistance to electrical currents) radio-frequency (SRF) technology,
similar to what we employ at TRIUMF for our new Advanced Rare
IsotopE Laboratory (ARIEL) electron accelerator. SRF accelerators
use much less input power than room-temperature accelerators and
are therefore capable of much-greater output power levels. CLIC is a
‘warm’ accelerator designed to go to higher energies than ILC, but until
CERN finds evidence of new physics that would motivate the higher
energies, the CLIC part of the team will focus on further developing
their technology.
TRIUMF is interested in very high power beams not achievable with ‘normal’
room-temperature conducting technology. In fact, the progress around the
world on the core ILC technology was a major reason TRIUMF selected SRF
technology for its electron accelerator at the heart of ARIEL. At TRIUMF, our
electron accelerator is about 30 m long, and so the ILC (now called the LC) is
1,000 times larger. So it is natural for us to work on the ILC.
Furthermore, Canada has a number of industries that will participate
in building the accelerator, which we expect to be hosted in Japan.
TRIUMF is working closely with the Japanese on this (and on several
other key projects).
The primary science goal of the ILC is to study the Higgs boson
discovered at CERN, in which Canada was a significant player. CERN can
certainly study the Higgs but not with enough precision as is needed. It
turns out the LC will make a Higgs boson just about every time the beams
collide (and many more), whereas CERN’s Large Hadron Collider produces
a Higgs boson only one in a billion beam collisions: the needle in a
haystack problem. The Higgs boson is unlike any particle ever discovered.
It is different from anything scientists have seen before and so a ‘Higgs
factory’ will allow scientists around the world to study its properties,
especially the property that is claimed to add mass to massless particles
that make up you and me. It may also teach us about dark energy and the
beginning of the Universe at the very first moments.
Rare isotopes open up new possibilities in terms of understanding
natural laws that govern the Universe, as well as new therapeutic
opportunities. Could you explain some of the research efforts that
have/will be pursued in collaboration with TRIUMF?
Rare isotopes can be used to probe the laws of physics. Because TRIUMF
produces intense beams of isotopes (by which we mean beams with
many such particles in them) it is possible to probe the very character
of nature’s symmetries. One example is time reversal symmetry. Let’s
consider a thought experiment. If you make a film of a ball bouncing up
and down on a table, and then watch the film and compare to watching
the film played backwards, you cannot tell the difference. Going
forward in time looks identical to going backwards time. In this case
we say that time symmetry is preserved. At TRIUMF we are planning
isotope experiments (one involves collaborators from Mexico and the
US) that look for cases where time symmetry is broken. It turns out this
is needed to explain why there is no primordial anti-matter in outer
space, left over from the Big Bang. Interestingly, similar isotopes may
be useful for cancer therapy. Heavy isotopes emit alpha particles that
are highly efficient in killing cells. If connected to a molecule that can
attach to the tumour cells, a lethal dose of damage can be applied with
little risk to healthy tissue.
Nuclear medicine is an important area of research at TRIUMF.
What are some of the discoveries that are being made in the area of
nuclear research?
TRIUMF has had a multi-decade research partnership with the University
of British Columbia (UBC) and the Pacific Parkinson’s Research Centre.
Parkinson’s is a disease associated with the inability of an individual to
produce dopamine, a neurotransmitter in the brain. The most significant
discovery, recognised around the world, is the fact that Parkinson’s
patients, when given a dopamine placebo, can sometimes produce
amounts of dopamine equal to that of a healthy individual. This fact
was first demonstrated in brain scans that could measure dopamine
production in the brain. TRIUMF produced the needed isotopes and led
the scanning centre for the UBC doctors that pioneered the research.
More recently, TRIUMF has been leading a national effort to produce the
world’s most popular isotope, technetium-99m, using a small medical
cyclotron accelerator. After worldwide shortages a few years ago due
to problems with ageing nuclear reactors that produced the isotope,
TRIUMF and a team of national partners focused on creating a method
that could create substantial amounts. These have been successful
with support from the Government of Canada. We are now working to
have this approach brought before the regulatory authorities to obtain
approval for patients throughout Canada as well as around the rest of the
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world. This Canadian innovation is receiving a great deal of international
recognition.
The scientific community believes there has been a worldwide
renaissance in nuclear science in recent years. Is there anything
specific that has prompted this resurgence?
The renaissance is due to the fact that after 40 years of studying stable
atoms, progress in understanding the nucleus had almost stalled in
the second half of the 20th Century. The breakthrough came when it
then became possible to create very exotic nuclei and accelerate them.
Instantly, theoretical models of nuclear structure were being challenged
with the new data; these challenges then reveal the opportunities
for making more sophisticated, inclusive models. Beams of unstable
isotopes are now produced at a few major labs around the world, and
several more ambitious facilities are being planned in the emerging
economies. The new data is driving the development of new models of
basic nuclear physics.
TRIUMF is among the leading laboratories in the world producing
rare isotope beams. In several cases, TRIUMF has the most intense
exotic beams anywhere, which allows nuclear physics to make
significant progress on its quest for the holy grail: an analytical
description of all nuclear behaviour and an understanding of the
origin of the chemical elements.
Have there been any particular achievements at TRIUMF that you are
most proud? What do you hope to achieve by the end of this year?
The most significant particle physics achievement in the world in the
last year was the discovery of the Higgs boson. This discovery is very
gratifying at every level for us. TRIUMF built a part of the accelerator,
a big piece of the detector, and is one of 10 centres around the world
that stores data from CERN. TRIUMF and Canadians played a major role.
Furthermore, in the last couple of years, TRIUMF and Canadian scientists
were involved in trapping anti-matter (actually anti-hydrogen) for the
first time. Another great achievement! TRIUMF has also led the world in
making the most precise measurements of atomic masses of unstable
nuclei. This has led to significant advances in our understanding of
nuclear structure. From the public perception, our work on Tc-99m, the
leading medical isotope in the world, is set to garner the most attention
because it will impact the lives of so many Canadians. By the end of this
year or early next year in collaboration with the BC Cancer Agency we
hope to start human trials with accelerator-produced Tc-99m. I think it is
important to note that TRIUMF and all its accomplishments have enjoyed
enormous support (both moral and financial) from the Government of
Canada, British Columbia, and citizens across the county.
Is TRIUMF involved in any other work that is expected to benefit the
public?
TRIUMF does many amazing things. We treat patients with eye cancer
(ocular melanoma) from across Canada in collaboration with the BC
Cancer Agency, and we irradiate electronics for dozens of companies
and the Canadian Space Agency to ensure their satellites work in the
‘radiation-unfriendly’ outer space environment. Along with Nordion, a
private Canadian company, we produce medical isotopes that touch the
lives of millions of people each year. In the next decade, once the unique
ARIEL facility comes online, TRIUMF will be in a position to make some
truly amazing discoveries using isotopes. As usual in science, progress on
one question leads to another and at the same time, the public surely will
benefit and be impacted from advances in the increased understanding
of Nature.
To conclude, what is your vision for the laboratory over the next five
years and beyond?
Five years ago we embarked on an ambitious plan to double the
scientific productivity of TRIUMF in the areas of advancing isotopes
for science and medicine. We are roughly two-thirds of the way
there. We must finish construction and then commissioning
of our new flagship facility, called ARIEL that will propel
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us to the forefronts of isotope research worldwide. With ARIEL, we will
seek to better understand how and why stars explode to produce the
heavy chemical elements that led to life as we know it on Earth. In the
fiery explosions of stars, many unstable isotopes are produced that
then decay to make the heavy stable chemical elements on Earth from
which everything is formed. This research programme will also lead
to a better understanding of the properties of the interior of neutron
stars, neutron star mergers that then explode creating isotopes that
are expelled into space, and X-ray bursts associated with binary star
systems involving white dwarfs or neutrons stars.
In some of our studies, we collaborate with partners around the world,
such as CERN in Switzerland and KEK in Japan to challenge some of the
most sacred tenets of physics by finding rare exceptions to the ‘rules’ of
particle physics. Is the Higgs boson really what we think it is, and does
it have anything to do with dark energy or the validity of the Big Bang
model? Does space have extra dimensions?
www.triumf.ca