Tag Archives: Physics

Shape coexistence and nuclear physics at TRIUMF

Our group didn’t know what to expect as we trekked across the rainy parking lot towards the modest entrance of TRIUMF at UBC. The small blue sign seemed like an almost comical understatement to the immense laboratories looming behind it. Having no physicists among us, we thought we were in over our heads with this research. We carried on regardless, and were greeted by friendly faces when we made it inside.


TRIUMF sign Source: self

We were met by Dr. Thomas Procter, a postdoctoral fellow at TRIUMF. Dr. Procter had invited us to the facility and offered to tour us round the facility. Not only did Dr. Procter give us valuable insight into his own research, but he introduced us to the world of nuclear physics at UBC.

TRIUMF Cyclotron

TRIUMF Cyclotron Source: triumf.ca

Nuclear physics is the study of atomic nuclei their characteristics and interactions with the world around them. It is this brand of physics that TRIUMF specializes in. TRIUMF is home to the largest cyclotron in the world: a gigantic machine used to generate exotic nuclei for (among other things) studies in astro- and nuclear physics.

For example, DRAGON (Detector of Recoils And Gammas Of Nuclear reactions) apparatus at TRIUMF is a machine used to examine the formation of the nuclei we see commonly on Earth in distant supernovae (Consider rephrasing sentence). In some cases, the specifics behind the formation of these nuclei would remain largely unknown if not for DRAGON. While we got only a brief insight into the functioning of DRAGON, we were fortunate enough to have a more elaborate look at some of the nuclear structure research at TRIUMF done by Dr. Procter.

Dr.Procter's set up Source: Self

Dr.Procter’s Set Up Source: Self

Dr. Procter is interested in a phenomenon that occurs in the nucleus called shape coexistence. The particular research paper of his that we looked at involved the isotope chain of rubidium 98. Dr. Procter and his team used TRIUMF’s powerful cyclotron to generate many isotopes of rubidium for their study. The video below gives an overview of nuclear shape detection by laser spectroscopy and some of the theory involved in Dr. Procter’s research.

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It is important to have at least a rudimentary understanding of the theory involved in Dr. Procter’s work before attempting to understand his methods. The following podcast gives a general overview into the laser spectroscopy used in Procter’s work and at TRIUMF.

Unless you are in the field, particle physics is not something that occurs to most people on a daily basis. One could argue that it has little relevance to their life, but in reality, it may be the most relevant science out there. There would be no life without particular interactions between particular particles that that hold us together. In essence, particle physicists ask the big question: “What are the building blocks that make up everything we can perceive (including us) and why do they behave the way that they do?”


Particle Accelerators are Really Expensive

Plasma inside of a Plasma Lamp, from Wikimedia Commons

Plasma inside of a Plasma Lamp, from Wikimedia Commons

Particle accelerators like the Large Hadron Collider (LHC) or the TRIUMF facility here at UBC are massive projects. The LHC cost roughly 7.5 Billion Euros to build, and has a circumference of 27 kilometers. These facilities allow scientists to perform all kinds of experiments about fundamental physics, but they take years and incredible amounts of money to construct. Ars Technica reported on an experiment at SLAC National Accellerator Laboratory at Stanford that could help reduce the cost of these projects by helping to accelerate particles faster in a shorter distance. All current particle accelerators work by using electromagnets to give energy to a stream of particles. Different designs arrange them in different ways, but the basic design involves a electromagnets arranged around a cavity which the particles pass through. Because the various particles that are accelerated are charged, they can be manipulated by electromagnets. Speeding them up is really not all that different from spinning up an electric motor or any other electromechanical device. The most powerful particle accelerators are large circular tunnels which pass the beam through the same cavities multiple times. The bigger the tunnels can be, the more speed can be added to the particles, which is a big part of why they’re so expensive. Building a 27 kilometer tunnel is expensive in and of itself, and the cost only grows when that tunnel needs to be built with incredibly precise dimensions. With science funding flagging in most developed countries, these costs might make it difficult for researchers to get the kind of investment they need to keep making progress on fundamental physics research using particle accelarators. What the SLAC group proposes is instead to use a field of plasma to transfer energy to particles. A state of plasma occurs when atoms are stripped of their electrons, leaving electrons and positively charged atoms floating freely around each other. The SLAC group found that when a group of electrons was passed through plasma, a “wake” (not unlike the wake of a ship on the ocean) followed them, pulling more electrons with them. These wake electrons were accelerated to nearly the speed of light, drawing energy from the surrounding plasma. This technique is far less straightforward than accelerating particles with electromagnets, but it is also far more efficient, so it could allow us to build more powerful particle accelerators without requiring as much space or money. There is still a great deal of research to be done on the dynamics of plasma, but this is a promising discovery.