How particle accelerators work at TRIUMF


A composite particle made up of a nucleus (a proton, or combination of protons and neutrons), as well as the electrons surrounding the nucleus.

What are particles?

You are made of atoms, and so is almost everything around you

—your teeth, your shoes, the pale blue dot we live on, and even the stars that burn in our own galaxy as well as those far away. 

Atoms are built from protons, neutrons, and electrons, which combine in different ways to form elements.

Research teams at TRIUMF and around the world use machines like particle accelerators to break or fuse nuclei (the dense cores of atoms) to learn more about the laws of our Universe and how we can harness them for the benefit of all.

Subatomic Particles

Atomic Particles


A subatomic particle that carries a positive electrical charge; also the atomic nucleus of hydrogen.


A particular ‘species’ of atom. Every element represents an atom with a particular number of protons and electrons, and these numbers define the element’s chemical behaviour.


A subatomic particle that carries no electric charge; neutrons join with protons to create the nuclei (the cores) of all atoms.


Electrically charged atoms that result when we add or take away electrons  from a regular atom.


A subatomic particle that carries a negative charge.


While each element has an atomic nucleus  with a unique proton number, the neutron number can vary. These different ‘flavours’  of the element are called ‘isotopes.’ 

TRIUMF is Canada’s particle accelerator centre.

TRIUMF is home to some of the most advanced particle accelerators in the world, including two made-in-Canada wonders—the world’s largest cyclotron of its kind and a state-of-the-art superconducting linear electron accelerator.

TRIUMF fosters an inclusive and increasingly diverse lab community that unites multidisciplinary teams spanning the fields of accelerator science, technology, and engineering. We work together with each other and our network to expand our knowledge of the Universe and apply science to solve problems and drive discovery and innovation.


The 520 MeV cyclotron is 18 m in diameter, sits in a concrete vault 3-storeys high, and is connected to 1 km of beamline.

If you dropped the cyclotron at centre ice in a standard NHL hockey rink, it would extend from blue line to blue line.


With the exception of a shutdown period for maintenance, servicing, and upgrades, the cyclotron typically operates 24 hours/day to provide beams of protons to researchers and commercial users who come to TRIUMF from all around the world.


The cyclotron was built using over 4,000 metric tonnes of steel. That’s as heavy as 40 blue whales!


The cyclotron accelerates protons up to 75% of the speed of light, 224,000 km/s. That’s fast enough to go to the moon and back in 2 seconds!

What are particle accelerators?

Particle accelerators, like the ones found at TRIUMF, are tools for accelerating charged particles (electrons, protons, and ions) up to very high speeds. High-speed beams of charged particles can be used to study the Universe at every scale, from the infinitesimally small to the unimaginably big.


We also use accelerated particles to create new and exotic atomic nuclei, which in turn can be used for science, medicine, and industry.

At TRIUMF, we have multiple particle accelerators,
including both cyclotrons and linear accelerators (linacs).

Charged Particle Source

Charged particles begin their life in a ‘source’ that provides a steady stream of electrons, protons, or ions to be accelerated. For example, for the TRIUMF 520 MeV cyclotron, the source ionizes hydrogen gas to create a hydrogen atom with an extra electron.



Beamlines are evacuated pipes that allow transport of the charged particles without collisions with air molecules.


Magnetic fields can change the direction of moving charged particles. We use strong electromagnets surrounding the beamline to bend, steer, and focus the beam of charged particles during transport.

Electric Fields​

Electrical fields can be used to deflect, push, or pull charged particles, and can thus be used for acceleration. They can be either static (for accelerating particles from near rest to up to low energy) or oscillating at microwave frequencies (for accelerating to high energy).


The accelerated charged particles can be directed to collide with a fixed target like a piece of metal foil, or a chamber filled with gas. This collision transmutes the atoms in the target, which produces other atoms, including radioactive isotopes. These isotopes are used for a broad range of scientific purposes, from medical imaging and disease treatment to analyzing the cores of far-off stars.


Detectors record and reveal particles and radiation that are produced in particle collisions. This information can be used for particle and nuclear physics research, accelerator science, astrophysics, medical imaging, and other research and industrial applications.

drives discovery
and improves
our world.

From the hunt for the smallest particles in our Universe to the development of isotopes to diagnose and treat disease, TRIUMF drives more than scientific discovery. We are pushing the frontiers of isotope science and innovation, as well as technologies to address fundamental and applied problems in particle and nuclear physics and the materials and life sciences.

Our passion for understanding everything from the nature of the nucleus to the creation of the cosmos sparks imagination and inspiration, improves health, creates economic opportunity, and builds a better world.

Discovery Science

Accelerators and detectors are essential tools of discovery for particle and nuclear physics. They enable us to peer into the cores of far-off stars to witness the birth of elements, to delve into the forces that hold protons and neutrons together in the nucleus, and to manufacture critical medical isotopes for imaging and treating disease.

TRIUMF has an expert team that develops and operates these machines, taking the technology to new frontiers for our lab and other organizations around the world (including the Large Hadron Collider at CERN).


Training and Education

As a nexus for interdisciplinary research and industry-leading innovation, we provide skills and knowledge for the next generation of game-changers. We engage with hundreds of students, postdoctoral researchers, and trainees every year.



TRIUMF is Canada’s premier laboratory for medical isotope production and research, and a world leader in advancing the frontiers of isotope science to improve lives everywhere.



Particle accelerators like TRIUMF’s cyclotrons and linacs, as well as the detector technologies we develop, are employed worldwide to investigate the properties of matter, characterize novel substances and materials, test space-bound satellites and technologies, reduce environmental impacts, and more.

TRIUMF’s global contribution 


The development and production of components for use in research both domestically and internationally is one of the key roles TRIUMF plays in enabling Canadian contributions to international collaborations. The laboratory’s Science and Technology Facility constructs some of the world’s most sensitive particle detectors – for matter and antimatter alike.


Several specialized facilities for fabrication, testing, and assembly are used for the development and production of components installed at TRIUMF, as well as other major laboratories such as CERN in Europe.


This work is one of the key roles TRIUMF plays in enabling Canadian contributions to international collaborations.

ATLAS small-strip Thin Gap Chambers Assembly Time Lapse

View ATLAS Detector Collaborations Infographic for more information.


ATLAS is one of several international particle detector projects in which TRIUMF contributes deep expertise in design, construction, installation, operations, and data analysis to support.   




ATLAS at CERN’s Large Hadron Collider (LHC), is one of the world’s largest scientific experiments. As part of the ATLAS-Canada collaboration, TRIUMF scientists, engineers, technicians, and students have provided critical expertise to the detector design, construction, installation, and data analysis for this global experiment.

For decades, TRIUMF has served as one of the major portals through which Canadian researchers contribute on and collaborate on major international research projects – and nowhere is this clearer than in the longstanding cooperation with CERN in Switzerland.


  • From 2006 to 2017, TRIUMF played host to one of 10 ATLAS Tier-1 computing centres located around the globe.
  • As Canada’s contribution to ATLAS’ global computing needs, this world-class facility is managed by TRIUMF staff and played an essential role in the Higgs boson discovery, enabling the data analysis, data reduction, and modeling that confirmed the particle’s existence in 2012, resulting in the 2013 Nobel Prize in Physics.


In recent years, the Centre has since been upgraded and moved to SFU where it is currently operating as a federation with the TRIUMF site.



The Institute for Advanced Medical Isotopes (IAMI) will be the new home for TRIUMF’s Life Sciences program. Kicked off by Prime Minister Justin Trudeau during his visit to the laboratory in November 2018, this facility equipped with a new 24 MeV medical cyclotron, is under currently under construction.


IAMI will add state-of-the-art laboratory facilities to help grow TRIUMF’s capacity in the life sciences to dramatically increase our ability to help advance isotope-based diagnostic, and therapeutic treatments for a range of diseases, including cancer.


IAMI’s construction is supported by contributions from the Province of British Columbia, the Government of Canada, TRIUMF, BC Cancer, BC Cancer Foundation, and UBC.

IAMI Construction Drone

For more information on some of the emerging medical isotope research taking place at TRIUMF,  watch the independently produced short documentary,
The Rarest Drug on Earth


In the coming years, TRIUMF will help advance critical research through its capacity to produce world-leading amounts of Ac-225 – a promising cancer fighting isotope.



The ISAC I and ISAC II experimental halls contain additional infrastructure that enables the separation, and re-acceleration of isotopes for use in experiments. The three linear accelerators operate sequentially, like the gears in a car, and are engineered differently for precise operating requirements:

    • The Radio Frequency Quadrupole is a first stage acceleration to approximately 2% the speed of light
    • The Drift Tube Linac for medium range acceleration
    • The Superconducting Linac for the highest energy rare isotope beams, which achieves velocities up to 20% the speed of light, for higher energy experiments inside ISAC II

In total, ISAC produces a variety of approximately 70 different rare isotopes, separated according to their mass and charge, and delivered on demand to researchers. This one of a kind combination of science and engineering technology is host to nearly 20 separate experimental facilities.


One of these is the Gamma Ray Infrastructure For Fundamental Investigations of Nuclei (GRIFFIN), which serves as the world’s most powerful tool for the decay spectroscopy of rare isotopes.


GRIFFIN is a collaboration led by University of Guelph, Simon Fraser University, and TRIUMF.


GRIFFIN is the world’s most powerful tool for decay spectroscopy of rare isotopes. This experiment provides scientists with an unparalleled view of the interplay of forces that create nuclear structure by measuring the gamma rays emitted from the radioactive nuclei of rare isotopes after they decay.


There are three distinct experimental facilities made possible by ISAC II’s superconducting linear accelerator.


ISAC Charged Particle Reaction Spectroscopy Station (IRIS) gives physicists a unique view of the strong force and unusual transformations in nuclear structure when nuclei are pushed to their limits.


  • IRIS leverages ISAC II’s ability to produce extreme, short-lived isotopes to induce nuclear reactions using a solid hydrogen target
  • This experiment enables researchers to construct an unparalleled image of nuclear structure at the extreme, particularly for valence nucleons – those furthest from the nuclear core

The Electromagnetic Mass Analyzer (EMMA) is a recoil detector in nuclear structure reactions, and a core part of TRIUMF’s nuclear astrophysics program.


  • EMMA excels at sifting, sorting, and detecting the recoils from a trio of nuclear reactions that take place in exploding stars, making the facility an ideal star simulator
  • It acts as a testing ground for studying the nuclear reactions in exotic, high-energy cosmic events, such as the X-ray bursts that occur within neutron stars


TRIUMF-ISAC Gamma Ray Suppressed Spectrometer (TIGRESS) is an in-beam gamma ray spectrometer, which has enabled a new era of high-precision nuclear structure experiments with rare isotopes.


  • TIGRESS is particularly powerful at enabling TRIUMF scientists to study how the number of neutrons and protons in a nucleus determines its shape
  • It fuels our understanding around how collective nuclear identity emerges from the basic interaction between protons and neutrons, and in turn, how this influences heavy element formation in stars
Learn more about TRIUMF research teams and tools on our Strategic Five Year Plan website.



The Meson Hall is the first and largest research hall on site. At the height of about four stories (combined with another four stories below ground), this building plays host to the heart of TRIUMF: the laboratory’s 520 MeV cyclotron – certified by the Guinness Book of World Records as the largest accelerator of its type in the world. This machine and the surrounding facilities are the core drivers of TRIUMF’s scientific programs.


Throughout the Meson Hall, the facilities range from supporting fundamental subatomic physics and materials science to enabling radiation testing and life sciences research – both significant examples of applied science with real-world impact. 


Some of these include the Proton & Neutron Irradiation Facility (PIF/NIF), the Centre for Molecular & Quantum Materials Science (CMMS), and TRIUMF’s former Proton Therapy (PT) facility. The Ultra-cold Neutron (UCN) facility and Life Sciences’ TR-13 cyclotron are also installed here.


The yellow concrete blocks, sometimes referred to as the lab’s LEGO Bricks, are used throughout the Meson Hall as radiation shielding for the beamlines and facilities connected to TRIUMF’s main cyclotron. 

Meson Hall Crane Ops At Work




The Advanced Rare Isotope Laboratory (ARIEL) is the most significant expansion project in the lab’s 50-year history, and will be among the few purpose-built multi-user rare isotope facilities in the world.


For insight into ARIEL’s construction explore these time lapse segments and this highlight reel from concept to commissioning. Some quick ARIEL facts include:


    • Once completed, ARIEL will be the world’s most powerful Isotope Separation Online (ISOL) complex
    • It uses a built-in-Canada linear electron accelerator to enable world-class research on the nature of atomic nuclei and the origin of heavy elements
    • ARIEL will be instrumental in future development and production of quantum materials and medical isotopes

Funded by the Canada Foundation for Innovation (CFI), six provinces, and with the backing from 21 universities, it will be commissioned and operational in phases between 2020-2026.


Watch our 15-minute Town Hall talks to learn more about how TRIUMF’s Life Sciences research is enabled by ARIEL’s significant capabilities.


The ARIEL facility will massively expand the rare isotope program by providing more exotic isotope species with very high intensities, allowing TRUIMF’s global community of researchers and students to more fully exploit the existing experimental facilities onsite.


Antimatter particles have the same mass as their matter counterparts, but qualities such as electric charge are opposite. Matter and antimatter particles are always produced as a pair and, if they come in contact, annihilate each other.


The DCR serves as the base for all security and safety operations on site. The control room has been expanded to also support e-Linac operations as the ARIEL facility is completed and commissioned over the next few years.



If the main cyclotron is the heart of the TRIUMF,  then the Driver Control Room (DCR) is its central nervous system.



The DCR is always occupied by at least two accelerator operators – 24 hours a day, 7 days a week, 365 days a year. Inside, operators monitor 3,000 hardwired devices that produce up to 50,000 signals of information.


While each element has an atomic nucleus with a unique proton number, the neutron number can vary. These different ‘flavours’ of the element are called ‘isotopes.’

Linear Accelerator

A linear particle accelerator increases the velocity of charged subatomic particles or ions by subjecting them to a series of oscillating electric potentials along a linear beamline

Decay Spectroscopy

Decay spectroscopy is a set of techniques used to determine the decay properties of radioactive nuclei by observing the particles emitted from a nucleus

Gamma Ray

Gamma rays have the smallest wavelengths and the most energy on the electromagnetic spectrum. On Earth, gamma rays can be generated by nuclear explosions, lightning, and radioactive decay.

Heavy Elements

The informal name for all elements with 93 or more protons in their nucleus, some of which can be produced artificially as part of accelerator-based experiments


A superconductor is a material that can conduct electricity with zero resistance. Most superconducting materials must be in an extremely low energy state (very cold) to become superconductive

Quantum Materials

Quantum materials are solids with unique physical properties that stem from unexpected interactions of their electrons


An elementary particle similar to an electron but are 207x heavier. because of this mass, muons are a primary applied science particle in TRIUMF’s molecular and quantum science division

Standard Model

Developed in the early 1970’s, the Standard Model of particle physics classifies the known building blocks of the universe, elementary particles, and explains their interactions with both each other and with 3 of 4 fundamental forces.

Matter-Antimatter Asymmetry

The Big Bang should have created equal amounts of matter and antimatter, but everything we see from in the universe is made almost entirely of matter. There is not much antimatter to be found. What happened to the antimatter?

Electric Dipole Moment

A measure of the separation of positive and negative electrical charges within a system. The dipole moment’s size is affected by the difference in electronegativity and the distance between the charges


A liquid that has zero viscosity – superfluids can flow across a surface without losing energy due friction with the surface


A subatomic particle that carries a positive electrical charge; also the atomic nucleus of hydrogen


A subatomic particle that carries no electric charge; neutrons join with protons to create the nuclei of all atoms



The 520 MeV cyclotron was declared commissioned in February 1976. Despite the pinwheel shape, the 520 MeV cyclotron doesn’t spin. An electric field changes direction 23 million times per second to accelerate charged particles to 224,000 kilometres per second inside a high vacuum chamber.


To put this into perspective, travelling at this speed would send you to the moon and back in 3.4 seconds. 


Key capabilities that set the TRIUMF cyclotron apart have allowed it to remain on the forefront of science after 45-years in operation.


  • Four beams of different energies and intensities can be extracted simultaneously.
  • It maintains one of the most extreme spiral angles, reflected in the TRIUMF logo, of any cyclotron. 


In this case H-minus ions cross the edges of the magnets at extremely low angles reaching 72 degrees at the outer orbits. High magnetic fields at high energies will detach the extra electron. For this reason the peak field is low making the cyclotron anomalously large for its top energy. This combination creates a huge advantage in extraction flexibility.


Play Video



View How Particle Accelerators Work at TRIUMF infographic to learn about science-technology. 


The cyclotron colors were selected by Canadian artist, B.C. Binning, making it TRIUMF’s first Arts & Culture collaboration. The colors were intended to serve as a wayfinding and safety countermeasure at the time, supporting visual orientation within a large and symmetrical structure.

TRIUMF’s irradiation 


Over the past five decades, researchers and technicians have leveraged the cyclotron’s capabilities in several ways to produce real-world impact.


  • The Proton Irradiation Facility (PIF) is used by partners like the Canadian Space Agency, Cisco, Boeing, and others to test electronics bound for high atmosphere or outer space.
  • Similarly, the Neutron Irradiation Facility (NIF) is relied upon by aerospace and computing companies; in total, TRIUMF welcomes around 200 international users to these facilities annually.


Cosmic Rays are a significant source of radiation here on earth. For example, during a flight at an altitude of 10,000 metres, you’re bombarded by 25x more neutron radiation than you are on the ground.


Using particle beams from our main cyclotron, scientists are able to simulate the effect of cosmic radiation on electronics. Replicating years of radiation exposure in space or high altitude environments allows scientists and engineers to test and improve radiation hardness in devices before they are installed in commercial airlines or launched into orbit.

Explore this interactive infographic to learn more about background radiation.



Within the Proton Therapy facility, cancer was treated using TRIUMF’s 520 MeV cyclotron. In partnership with BC Cancer, beams of protons were used for the treatment of ocular melanoma, a rare cancer of the eye.


Today, there are several proton therapy centres in North America, and while TRIUMF’s Proton Therapy facility has ceased operations, TRIUMF and BC Cancer continue their collaboration on several other existing and future facilities.


Decommissioned in 2019, TRIUMF provided this service for 25 years treating over 200 patients from both Canadian and abroad. 

TRIUMF’s 13 MeV cyclotron is the smallest cyclotron on site, and is similar to those installed in most urban hospitals used for the production of medical isotopes for clinical use.


In collaboration with partners such as the University of British Columbia (UBC), the TR-13 creates short-lived isotopes (such as Carbon-11 and Fluorine-18) that can be transported to UBC Hospital via high pressure pneumatic “Rabbit Line”.


The rabbit line sends isotopes to the hospital 2 kilometers away at speeds over 100 km/hour making the journey from TRIUMF in approximately 2 minutes.



This centre is one of only a few in the world that uses particle beams of muons and rare isotopes to characterize the electronic and magnetic properties of advanced quantum materials under a range of conditions.


As researchers develop new materials and new applications for existing materials, it’s often necessary to understand and understand the materials’ characteristics at the atomic-level.


Each year more than 150 Canadian and international scientists bring their material samples to CMMS for testing, most notably in areas of magnetic materials, and high temperature superconductors research.

Aiming to be the world’s highest-density source


This facility produces fast neutrons by stopping a beam of protons in a block of tungsten. These fast neutrons are slowed by scattering in heavy water at room temperature, then slowed further in superfluid (liquid) helium. At this speed, neutrons can be trapped inside special “bottles” and observed.


The flagship experiment for the UCN facility will be a world-leading search for the neutron electric dipole moment of the neutron, which may help us better understand matter-antimatter asymmetry and progress research beyond the Standard Model of particle physics.


This facility is capable of capturing neutrons at observable speeds of 7 metres per second or 25km per hour. 

UCN Construction Time Lapse


The dense cores of atoms, which are made of protons and neutrons (with the exception of hydrogen)


Beamlines are evacuated pipes that enable the transport of particle beams without interactions or collisions with air

Global Detector Collaborations

As part of the ATLAS-Canada collaboration, TRIUMF has provided critical expertise to the detector design, construction, installation for this global experiment.


This facility is managed by TRIUMF staff and played an essential role in the Higgs Boson discovery, enabling the data analysis, data reduction, and modelling that confirmed its existence in 2012.


IAMI add new state-of-the-art laboratory facilities, to dramatically increase TRIUMF’s ability to help advance isotope based diagnostic and therapeutic treatments for a range of diseases such as cancer.


The third stage of ISAC’s infrastructure is the superconducting linear accelerator that links these two research halls and feeds several high-energy research apparatus.


The isotope separation and acceleration research halls include three linear accelerators operate sequentially, like the gears in a car, and are engineered differently for precise operating requirements.

Meson Hall

The Meson Hall is the first and largest research hall on site. At the height of about four stories (combined with another four stories below ground), this building plays host to the heart of TRIUMF.


ARIEL, among the few purpose-built multi-user rare isotope facilities in the world. Powered by a built-in-Canada linear electron accelerator enabling world-class research and discovery.

Driver Control Room

The base for all security and safety operations on site, and is staffed 24 hours a day, 7 days a week, 365 days a year by at least two accelerator operators.

520 MeV Cyclotron

This machine, declared The Guinness Book of World Records: world’s largest  Cyclotron of its kind, accelerates H- particles to 75% the speed of light through the use of magnets and electric fields.


Using particle beams from the main cyclotron, scientists are able to simulate the effect of cosmic radiation on electronics, leveraging the cyclotron’s capabilities in several ways with real-world impact.

Valence Electron

Electrons in the outermost shell of an atom that can participate in the formation of chemical bonds with other atoms

Applied Life Sciences

Innovative life science treatments and critical isotope production capabilities are more ways TRIUMF’s main cyclotron accelerator has created lasting value with global impact.


Mesons are short-lived, unstable subatomic particles – composed of one quark and one antiquark bound together by strong interactions – that were of particular interest to researchers in the 1960’s and 1970’s.

Discover our Glossary to explore more terms used on this site. 

Centre for Molecular and Materials Science

One of the few facilities in the world that uses particle beams of muons and rare isotopes to characterize the electronic and magnetic properties of advanced quantum materials under a range of conditions.

Ultracold Neutron Facility

Aiming to be the world’s highest-density source of ultra-cold neutrons. The flagship experiment for this facility will be a world-leading search for the neutron electric dipole moment of the neutron.