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TRIUMF: Canada's National Laboratory for Particle Physics

Linda Crampton has an honors degree in biology. She has taught high school biology, chemistry, and physics as well as middle school science.

A view seen at the start of a tour

A view seen at the start of a tour


TRIUMF is Canada's national laboratory for particle physics and accelerator-based science. It's also the site of the largest cyclotron in the world and an important creator of medical isotopes. The facility is located in Vancouver on the University of British Columbia campus. It's operated by a consortium of Canadian universities, however. Free tours are offered to visitors, who are welcome to take photographs. The laboratory is a fascinating place to explore and to learn about science.

In this article, I describe some of the equipment in the TRIUMF laboratory and include observations made during a guided tour of the facility with students. Many interesting things can be seen during the tour, and the tour guides are knowledgeable about the facility. The sight of all the complex equipment used to explore the mystery and power of the subatomic world is awesome.

TRIUMF stands for Tri-University Meson Facility. The facility was originally run by three nearby universities—the University of British Columbia, Simon Fraser University, and the University of Victoria. Additional Canadian universities are now involved. A meson is one type of subatomic particle.

The Guided Tour of the Facility

The guided tour for the general public takes place at 1 pm on Wednesdays and lasts for an hour. The tour is free but registration is required. Visitors can register online. The first fifteen registrants are accepted for each tour. The TRIUMF website should be checked before a visit to see whether this information has changed. This is important because the tour has been cancelled during the coronavirus pandemic. The facility plans to restore it at some point.

Based on my experience on my school's field trip, there are three main areas shown to visitors. After listening to a description of the cyclotron model displayed in the reception area, the first sight is a large hall filled with many types of equipment and multiple experiments in progress. It's fascinating to see, but to an inexperienced eye it looks a bit disorganized. The system is obviously effective, though, since TRIUMF does valuable work.

After seeing sights at multiple levels in the hall, the tour goes to the office area. Here the data centre with its many computers and multiple screens of information can be seen. The office area also includes interesting photos related to the facility.

The climax of the tour is the visit to Meson Hall. More experiments can be seen here, but the highlight is being close to the largest cyclotron in the world. The hall also describes the uses of the facility's cyclotrons in medicine.

Tours of TRIUMF for six or more people can be booked. The facility's website says that "we will do our best" to book a desired time for a group's visit. The contact information is located in the "For the Public" section of the website.

The tall stacks of staggered blocks cover the roof of the cyclotron vault and absorb radiation. The lights indicate that the cyclotron and two beam lines are operational.

The tall stacks of staggered blocks cover the roof of the cyclotron vault and absorb radiation. The lights indicate that the cyclotron and two beam lines are operational.

Meson Hall

The cyclotron is located underground in a site known as the cyclotron vault. It's too dangerous to visit the device when it's operating because of the radiation that's released as particles break down. The surface area near the operating cyclotron is safe for people, however. Staggered stacks of concrete blocks cover the area where the device is actually located and absorb the radiation.

The purpose of the cyclotron is to produce an intense beam of highly energetic protons moving at tremendous speed. The protons that emerge from the device have a maximum energy of 500 million eV (electron volts) and a maximum speed of 224,000 km per second, or three quarters of the speed of light. The protons are sent along beamlines to various places for experiments or for medical use.

Looking in the other direction in Meson Hall; the stacks of blocks cover a specific beamline

Looking in the other direction in Meson Hall; the stacks of blocks cover a specific beamline

Structure of a Cyclotron

Inside a cyclotron, there is a cylindrical vacuum tank containing two semicircular, hollow, and D-shaped electrodes known as dees. The straight sides of the dees face each other, as shown in the video screen below. There is a narrow gap between the electrodes. At this gap, the dees are connected to a single alternating voltage source, or an oscillator. Each dee is connected to a different terminal of the oscillator. As a result, an electric potential difference and an electric field is created across the gap.

A large magnet is located both above the vacuum tank and below it. The magnets are arranged so that opposite poles face one other, thereby creating a magnetic field in the tank.

Beamlines send particles into the vacuum tank and remove them after their journey. Like the tank, the beamlines contain a vacuum to prevent the particles from colliding with those in air.

How a Cyclotron Works: A Basic Overview

Charged particles are dropped into the centre of the gap between the dees through a pipe known as an injection beamline. The particles enter a dee and travel through it via a circular path. A positive particle is drawn towards the dee having a negative potential and a negative particle is drawn towards the positive dee. The polarity over the gap between the dees is alternated each time the particle reaches the gap in order to draw the particle into the opposite dee.

As the particle goes through the electric field in the gap, it gains energy and accelerates. This process is repeated multiple times, causing the particle's energy and speed to gradually increase as it travels around the dees (although "gradually" is still a rapid process). Adding all the energy that the particle needs via one trip through an electrical field isn't practical because a tremendous voltage would be needed to create the field.

An accelerated particle in a magnetic field follows a curved path, which is why the particles follow a circular route through the dees. As the acceleration and energy of the particles increases, they travel along a circle of a wider and wider diameter and spiral outwards through the dees. When the particles reach the outermost part of the electrodes, they are withdrawn through a pipe known as an external beamline. The beam of highly energetic particles is then directed at atoms in a target.

How Are the Accelerated Particles Used?

The particles released from the cyclotron are sometimes used to break up atoms in order to study their structure. Another purpose of the particles is to create and study exotic particles, which may help scientists to understand the universe and its creation. Yet another purpose of the particles is the creation of medical isotopes for the diagnosis and treatment of disease.

More Facts About the TRIUMF Cyclotron

The particles that are fed into the TRIUMF cyclotron and accelerated are negatively-charged hydrogen ions. Each ion consists of one proton and two electrons. The electrons are stripped from the hydrogen ions at the end of their journey through the cyclotron, creating isolated protons. The electrons are removed as the hydrogen ions travel through a thin layer of carbon foil, which removes the lightweight electrons.

The TRIUMF facility also contains smaller cyclotrons that produce particles with lower energy. In addition, some beamlines from the main cyclotron extract protons with lower energies than others.

One interesting trivia fact that is not on the display board below is that the cyclotron accelerates 1000 trillion particles per second.

Not-so-trivial facts about the cyclotron

Not-so-trivial facts about the cyclotron

Effects of a Magnetic Field

Although the radiation from the cyclotron is blocked and doesn't reach Meson Hall, a magnetic field does reach visitors. The field is harmless to the human body and doesn't damage credit cards or consumer electronic devices. TRIUMF recommends that people with implanted medical devices check with their doctor about the sensitivity of the devices to magnetic fields, however. Examples of devices whose function may be affected include pacemakers, shunts and stents, and infusion pumps.

One interesting effect of the magnetic field is the fact that paper clips stand on their end when they're dropped near the cyclotron. Even the senior students from my school enjoyed dropping and carrying paper clips to see the results.

If you'd like a tour preview or a substitute tour, the video below is a good one to watch. It includes views of standing paper clips near the beginning. TRUMF's website is also worth viewing. It announces special events that local people can attend and also has news that online visitors can read.

Facts About Medical Isotopes

Isotopes are forms of an element whose atoms have more neutrons than normal. Some isotopes are stable, but others break down soon after they form, releasing radiation in the process. These isotopes are known as radioactive isotopes or radioisotopes. Most radioisotopes are harmful to humans, but some are not harmful when used in tiny and very specific amounts and are actually helpful in medicine. Medical isotopes are used for both diagnosis and treatment.

Some radioisotopes are used to destroy cancerous tumours. Others are used as tracers that allow doctors to follow a particular process in the body. They are also used to provide a helpful view of a specific area in the body. The radioisotopes become incorporated into a process or area—often after being attached to a carrier substance that is normally present inside the body—and release radiation. The radiation doesn't harm the patient but can be detected, helping doctors to diagnose a health problem.

TRIUMF produces medical radioisotopes for PET (Positron Emission Tomography) imaging. A positron is the antimatter version of an electron. Positrons are released from the nucleus of the medical isotopes as they break down in the body. The positrons then interact with nearby electrons. This process destroys both the positrons and the electrons and triggers the release of radiation in the form of gamma rays. The radiation is detected in the imaging process.

Safety Issues

For most people, there are no safety issues related to a visit to TRIUMF. There may be exceptions for some people, however. Young children must be prevented from touching things that they see, except for things that are meant to be touched, like paper clips. Since there are quite a lot of steps to climb during the tour, it might not be suitable for people with certain health or mobility problems. The potential effects of the magnetic field on medical implants is another possible safety issue, as mentioned above. More information about safety is given on the facility's website. The website also has information about getting to the facility.

When visitors leave the research area of the facility and walk back to reception, they pass through a radiation detector. All of the students and staff from my school had no detectable radiation in their bodies. The facility also performs regular checks of the environment surrounding the facility and finds no increased radiation beyond the normal background level. The staff are well aware of both the benefits and the potential dangers of their work and make sure that safety is maintained. I have no worries about taking a tour again and am looking forward to my next visit. TRIUMF is a fascinating place.


  • Information about cyclotrons from the Columbia University in the City of New York
  • PET scan information from John Hopkins Medicine
  • Description of the cyclotron from the TRIUMF laboratory website
  • FAQ about medical isotopes and cyclotrons from the TRIUMF laboratory website

© 2016 Linda Crampton


Linda Crampton (author) from British Columbia, Canada on June 03, 2020:

Hi, Peggy. Radioactive isotopes are certainly useful. I've never read about a accident at the facility. I read the local news quite often, so I think I would have seen a report about a major incident. It is something to be concerned about, though.

Peggy Woods from Houston, Texas on June 03, 2020:

It is marvelous that medical diagnoses and treatments can be used from the radioactive isotopes created by machinery such as this. Since there is risk of radiation, I wonder if there has ever been an accident similar to the meltdown of nuclear plants?

Linda Crampton (author) from British Columbia, Canada on January 24, 2017:

Hi. I don't know Dr. Laxdal's email address. I suggest that you visit the TRIUMF website and click on the word "Connect" on the left hand side of the screen. This will give you the email address of the facility. If you send a message to the facility I expect you'll find the help that you are looking for.

Linda Crampton (author) from British Columbia, Canada on December 19, 2016:

Thank you for the comment, Dianna. I think TRIUMF is worth visiting for everyone. A person who knows something about physics may appreciate the tour more, but I think it would be enjoyable for other people, too.

Dianna Mendez on December 19, 2016:

What an interesting post. I do not quite understand physics but this place looks like it would be well worth seeing. My son, a physics expert, would most likely love a tour here.

Linda Crampton (author) from British Columbia, Canada on December 12, 2016:

I agree, Mel. It is impressive that such large and complicated equipment is needed to explore the subatomic world. Thanks for the visit.

Mel Carriere from Snowbound and down in Northern Colorado on December 12, 2016:

I am glad they are not using these to build bombs. It is fascinating that such a massive machine is required to look into a world so infinitesimallly small. Great hub.

Linda Crampton (author) from British Columbia, Canada on December 08, 2016:

Hi, Vellur. Yes, it was a great experience. It's a fascinating facility to visit. Thanks for the comment.

Nithya Venkat from Dubai on December 08, 2016:

Enjoyed reading about TRIUMF. The cyclotron is amazing! It must have been a great experience to visit the facility with your students, thank you for sharing.

Linda Crampton (author) from British Columbia, Canada on December 08, 2016:

Thank you very much, Cynthia. I appreciate your comment and support a great deal.

CMHypno from Other Side of the Sun on December 08, 2016:

Looks like a fascinating and informative place to visit Linda. Thank you for such an interesting hub,

Linda Crampton (author) from British Columbia, Canada on December 07, 2016:

Thanks, Nell. Now that I've seen the facility once, I'll definitely be going again. There's a lot to see. It would be very interesting to do research there!

Nell Rose on December 07, 2016:

Now this is my kind of thing! I love physics! And if I can't go and see the hadron collider then I am coming to see this one! lol! would love to work in this facility, great article!

Linda Crampton (author) from British Columbia, Canada on December 06, 2016:

Thanks for the visit and the comment, Martie. The process leaves me in awe as well!

Martie Coetser from South Africa on December 06, 2016:

Alicia, this is so-so interesting, but still beyond my comprehension. Somewhere I miss a couple of basic theories. So, I simply accept that a Cyclotron is an accelerator that imparts energies of several million electron-volts to rapidly moving particle, and people can do something positive and well-needed with the energy. Thanks for leaving me in awe :)

Linda Crampton (author) from British Columbia, Canada on December 05, 2016:

Hi, Flourish. I think that astrophysics would be a very interesting subject to study. Thank you for the comment.

FlourishAnyway from USA on December 05, 2016:

My husband would love that place. He started out wanting to do astrophysics in college but changed to chemical engineering.

Linda Crampton (author) from British Columbia, Canada on December 05, 2016:

I'd love to visit the facilities that you mention, Heidi. Happy Holidays to you, too!

Heidi Thorne from Chicago Area on December 05, 2016:

Well, if you can't make it to CERN to see the Large Hadron Collider, this might help you scratch your particle physics itch here in North America (although here in the Chicago area, we have Fermilab and Argonne). Definitely something to put on a "visit to Vancouver" list. Thanks for sharing your tour with us! Happy Holidays!

Linda Crampton (author) from British Columbia, Canada on December 05, 2016:

I think it's cool, too, Larry! It's a great place to visit.

Larry Rankin from Oklahoma on December 05, 2016:

Cool facility!

Linda Crampton (author) from British Columbia, Canada on December 05, 2016:

Hi, Bill. Yes, I think the tour would be very interesting for people even if they didn't have a background in physics or science. Thanks for the comment.

Bill Holland from Olympia, WA on December 05, 2016:

The study of particles is so far beyond my grasp as to seem insignificant, but I would totally enjoy a tour of that place. It would be fascinating, even if I didn't understand most of it. :)