bNMR

At TRIUMF’s unique βNMR (beta-detected Nuclear Magnetic Resonance) facility, scientists are using radioactive isotopes to take inside-out, atomic-level snapshots to guide the way to new materials and medicines.

βNMR (the Greek-letter β is pronounced ‘beta’) is a next-generation form of the better-known Nuclear Magnetic Resonance (NMR), one of the most important tools in science for characterizing substances. Both work by analyzing atomic-level magnetic fields, and the way that these fields change in certain conditions.

But βNMR is NMR on steroids. βNMR is a billion-times more sensitive.

The higher-resolution view βNMR provides is critical in the current search for superconductors and nanomaterials, and to better understand complex, biologically important molecules. For these materials, knowing a substance’s overall qualities isn’t enough. For example, scientists need to characterize the special electrical or magnetic properties at material surfaces, or at the metal ion binding sites around which biomolecules fold.

This is where βNMR excels.

βNMR wields incredible power to resolve materials at the atomic level by embedding polarized radioactive isotopes into a substance.

Beta decay (the beta in βNMR) is a form of radioactive decay in which an unstable nucleus becomes more stable by emitting a fast, high-energy electron: a beta particle. At TRIUMF, scientists produce rare isotopes, particularly lithium-8 (⁸Li) and magnesium-31 (³¹Mg), which decay and emit beta particles at just the right rate for collecting exquisite, atomic-level details.

In the βNMR facility, isotopes from the beam line are fired into a solid material, or proteins in water, at just the right energy to come to rest where they can provide information that’s of interest to researchers.

Since the isotopes are polarized, or all spinning in the same direction, the researchers know how the isotopes are oriented before they embed within the sample. Once at rest, each embedded isotope is affected by the magnetic characteristics of its local atomic environment, which also affects the emitted beta particle. The beta particle therefore carries a detailed characterization of the local magnetic fields within the substance, which is recorded by a beta particle detector.

This makes each beta particle equivalent to a photon of light that your camera detector would record in taking a picture. The result: An Instagram-worthy spectrogram, one prized by scientists because it provides critical, otherwise inaccessible information about the sample’s nanoscale structure and electromagnetic qualities.

βNMR’s high level of sensitivity comes from its combination of a high percentage of both isotope polarization and beta particle detection.

TRIUMF’s unique βNMR facility supports key research for TRIUMF scientists, collaborators and visiting users in the Centre for Molecular and Materials Science (CMMS) and in the Life Sciences division.

The βNMR facility is the product of the lab’s world-leading advanced isotope and accelerator science, technology, and multidisciplinary personnel, enabling the production of unique beam lines and spectrometers.

For both CMMS and TRIUMF life sciences researchers, the βNMR facility provides intense, highly polarized beams of rare isotopes with well-characterized beta-decay characteristics that act as sensitive probes of local conditions in target materials.

Centre for Molecular and Materials Science (CMMS)

At CMMS, βNMR is opening the door as never before to the localized study of the magnetic and electronic properties of ultra-thin films, nanostructures and interfaces. TRIUMF βNMR’s primary advantages for the study of condensed matter are:

1. The ability to adjust the beam energy in order to precisely control the implantation depth of the lithium-8 (⁸Li) probe in solids. TRIUMF researchers have demonstrated the ability to control the implantation depth to just 2.5 nanometres, or about 25-times the size of an atom. This makes βNMR an extremely sensitive probe of local condensed matter conditions, for example in developing next-generation batteries with increased storage capacity and reduced charging times.
2. TRIUMF scientists have demonstrated that the lab’s lithium-8 (⁸Li) βNMR facility can effectively measure novel detail about nano-level electromagnetic characteristics at surfaces and interfaces. This includes structure, phase transitions and barrier dynamics. This makes βNMR a powerful new tool for optimizing functionality in novel nanostructures, and identifying materials with localized novel magnetic or superconducting characteristics. This ability is particularly important with the further miniaturization of electronic components, such as transistors, where electronic and magnetic phenomena at surfaces and interfaces play a larger role in overall functionality.

Life Sciences

TRIUMF’s Life Sciences division researchers are pioneering the use of βNMR in characterizing the role of metal ions in biologically important biomolecules. Many biomolecules, including chlorophyll, RNA, insulin, or beta-amyloid have structures that fold around key metal ions, including Mg, Cu and Zn.

In βNMR, a radioactive metallic isotope is incorporated into a biomolecule’s structure to act as an incredibly sensitive built-in probe transmitting otherwise unattainable information. This is done through the beam implantation of radioactive metallic isotopes, including ³¹Mg, into solutions of target molecules.

TRIUMF’s βNMR offers the first opportunity to study localized structure and dynamics around metal ions in biomolecules. This major advance is facilitated by:

1. TRIUMF’s βNMR researchers have provided the proof-of-principle that beam embedded ³¹Mg isotopes become functionally bound in biological samples. This βNMR achievement opens a new scientific frontier in the detailed characterization of metal-ion related protein structure and dynamics.
2. The invention of TRIUMF’s new patented liquid-phase βNMR spectrometer optimized for the study of biological samples. The new βNMR spectrometer will provide an unprecedented quadrapole spectroscopic perspective on liquid samples at biologically relevant temperatures under vacuum conditions. In conjunction with the existing βNMR spectrometers, the new spectrometer will provide for triple data-taking within one experiment.

To learn more, please visit the TRIUMF βNMR website.