Reactions induced by alpha-particles that result in the emission of neutrons play a critical role across multiple disciplines of fundamental and applied nuclear physics. However, essential cross-section data for many key (α,n) reactions are either discrepant or entirely unmeasured. In nuclear astrophysics, this deficiency severely impacts models that describe how heavy elements are formed...
One of the biggest questions in nuclear astrophysics regards how elements are synthesized in stellar environments. Observations of astrophysical phenomena provide us with evidence for different nucleosynthesis processes, and modelling these astrophysical scenarios requires a detailed description of the complex nuclear physics that is involved. Radioactive decay, nuclear reactions, and the...
Beta-delayed neutron emission is an important decay mode for very neutron-rich nuclei. For the highly asymmetric nuclei, nuclear structure and large decay energies can affect neutron emission probabilities.
Experiments at the ISOLDE Decay Station (IDS) and the FRIB Decay Station Initiator (FDSi) provided a wealth of new data, leading to spectroscopy of beta-delayed two-neutron emission...
Beta-decay spectroscopy is a uniquely powerful probe, permitting often first experimental access to the excited states of exotic nuclei, but also a breadth of rich and detailed information when statistics permits. The experimental facilities at TRIUMF, combined with new beams delivered from ARIEL, are an exciting combination for future decay measurements. I will discuss some of the...
TIGRESS has been used successfully over the past decade for nuclear structure studies using Coulomb excitation, coupled to the BAMBINO array of dual silicon detectors. I will briefly introduce the method, the benefits of the experimental setup and highlight some recent successes. I will then discuss future opportunities for the programme, focussing on the new capabilities that ARIEL will deliver.
Transfer reactions provide a powerful and selective tool to probe the
microscopic structure of atomic nuclei. In particular, they are
sensitive to single-particle occupancies and wave-function overlaps,
offering direct insight into the interplay between single-particle and
collective degrees of freedom. This makes them ideally suited to
investigate shape coexistence in nuclei.
In this...
Octupole-deformed nuclei represent quantum many-body systems in which spatial reflection symmetry is broken in the body-fixed frame, while the symmetry must be restored in the laboratory frame. Such nuclei therefore provide a unique opportunity to investigate fundamental symmetry properties in atomic nuclei. However, the nature of octupole deformation remains insufficiently understood because...
The XT03 beamline at HIE ISOLDE provides a versatile station for reaction studies, centred on the SEC chamber, which has hosted numerous experiments during its first decade of operation. Halo nuclei such as ¹¹Li and ¹⁴Be offer a unique opportunity to investigate di neutron correlations and the evolution of shell structure in light neutron rich systems.
The ground state of ¹¹Li contains mixed...
A wealth of experimental data supports the important role played by pairing correlations in atomic nuclei. In analogy to superconductors, nuclear "Cooper pairs” have a strong influence on many properties such as binding energies, excitation spectra, deformations, moments of inertia, etc.
The study of pairing correlations in exotic nuclei is a subject of active research in nuclear structure....
The ACTAR TPC device is a time projection chamber, developed for nuclear physics experiments,that allows for the 3D tracking of charged particles in an active gas volume. It has been used since 2019 during several campaigns at GANIL (Caen, France), and in 2025 at TRIUMF (Vancouver, Canada). The detector was designed to work as an active target (the gas acts as a target for nuclear reaction) or...
Precision measurements of the final-state products in nuclear beta decay and electron capture (EC) decay processes can be used as powerful laboratories to search for beyond standard model (BSM) physics from the meV to TeV scale, as well as for targeting fundamental questions of quantum mechanics at the subatomic scale. For the past seven years, the BeEST (Beryllium Electron capture in...
SALER (Superconducting Array for Low-Energy Radiation) is a new experimental platform that uses superconducting sensors to study radioactive decay through direct detection of eV-scale nuclear recoil and other low-energy observables. The approach has already been developed and tested in the rare-isotope environment at FRIB, establishing its promise as a powerful new tool for precision decay...
Many experiments at radioactive ion beam (RIB) facilities require isobarically and isomerically pure beams at high ion intensities. Over the years, Multi-Reflection Time-of-Flight (MR-ToF) devices have gained remarkable attention for mass separation of short-lived radionuclides. They exceed mass resolving powers of m/Δm =1e5 within a few (tens of) milliseconds. Space charge effects, however,...
Precision mass measurements of exotic nuclei provide a direct and model-independent probe of nuclear structure, giving access to binding energies and derived observables such as two-neutron separation energies, shell-gap indicators, and odd-even staggering. At TRIUMF-ISAC, these techniques have enabled detailed studies of neutron-rich nuclei relevant to shell evolution, deformation, and the...
Tackling the increasing challenge to determine the mass of isotopes having low production yields and short half-lives, multi-reflection time-of- flight (MRTOF) mass spectrometry has grown from an initially rarely-used technology to the world's most commonly-used method for measurements with a relative mass precision down to $\delta m / m = 10^{-8}$. This technology has been developed at...
The multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) has been part of the TRIUMF’s Ion Trap for Atomic and Nuclear Science for about 9 years. Coupled to the ISAC facility for the delivery of rare isotope beams (RIBs) plenty of results have been shown, from extending the landscape of known nuclear masses to aiding for the development of ion sources and targets. Within the ARIEL...
This talk will discuss ab initio calculations around neutron-rich shell closures relevant for the evolution of shell structure, for electromagnetic moments, as well as for nuclear masses and beta decays for the r-process.
Reactions populating unbound states, such as transfer, breakup or knockout, provide valuable spectroscopic information of weakly bound nuclei. Extraction of meaningful information from these reactions require the combination of a suitable reaction framework, tailored to the reaction at hand, with a realistic structure model for the involved nuclei.
In this presentation, I will discuss some...
To achieve experimental breakthroughs in quantum gravity, there is significant interest in searching for violations of the gravitational inverse-square law—probing large extra dimensions predicted by string theory—as well as violations of Lorentz symmetry. This talk presents recent progress and upcoming experimental projects in these fields. In particular, we will discuss testing Lorentz...
The experimental nuclear physics program at Central Michigan University encompasses the pillars of low energy nuclear science, including applications to astrophysics, nuclear structure and fundamental symmetries. In this presentation we will describe the current research program at CMU and possibilities for future experiments that will combine the capabilities of the ARIEL facility and the...
Radium isotopes near $A=$220-230 exhibit strong octupole correlations, evidenced by low-lying negative-parity states and enhanced E3 transition strengths in even-even nuclei [1,2]. However, whether the underlying octupole deformation is static (a genuine ground-state symmetry breaking) or dynamic (a collective shape vibration) remains an open question.
In this contribution, the possibility...
Dual-mode solenoidal spectrometers combine flexibility, high detection efficiency, and precise kinematic reconstruction for reaction studies with rare isotope beams. This concept enables operation in two complementary modes: an active target mode employing a gaseous Active Target Time Projection Chamber (AT-TPC) for studies with low-intensity or extended targets, and a silicon detector array...
Employing storage rings for precision physics experiments with highly charged ions (HCI) is a powerful approach – yet the full potential of this method remains to be unlocked at low energies. Storage of freshly produced secondary particles in a storage ring is a straightforward way to achieve the most efficient use of these rare species.
All presently operating heavy-ion storage rings are...
Electron scattering is a powerful tool for probing nuclear structure,
because it enables model-independent studies. For instance, elastic electron scattering accurately provides the charge density distribution of nuclei, directly reflecting their nuclear shape. Furthermore, inelastic electron scattering and other electron-induced reactions significantly aid our understanding of nuclear...
A long-standing goal of nuclear theory is development of a predictive ab initio framework for nuclear structure and reactions. One such framework is the no-core shell model with continuum (NCSMC), in which the many-body wave function is expanded in terms of eigenstates of the many-body Hamiltonian obtained within the no-core shell model (NCSM), i.e. using the harmonic-oscillator basis, and...
Measuring Atomic Parity Violation (APV) in the weak interaction is an excellent way to test the standard model at low momentum scales. One way to do this is studying parity violating transitions in alkali atoms. Francium is the ideal element to use in these searches, as its heavy mass gives a relativistic enhancement to parity violating transitions 18 times that of Cesium. The Francium...
ARIEL presents a new playground not only for nuclear physics, but also for medical applications of nuclear physics. ARIEL has the capability to produce photons for FLASH radiotherapy (RT), a capability currently available at only a few laboratories worldwide. In 2021, in vivo FLASH RT and conventional RT experiments were performed on mice using 10 MV photons at ARIEL.
Production of Ac-225, an...
The combination of a germanium detector array, charged particle detector
and recoil mass spectrometer with the neutron-rich radioactive beams
available upon completion of ARIEL
will allow for an entirely new suite of measurements using
fusion-evaporation, radiative-capture, and transfer reactions. This
presentation will discuss the selectivity achieved by coupling the
TIGRESS...
Neutrinoless double-beta decay ($0\nu\beta\beta$) offers a way to probe for physics beyond the Standard Model. Observation of $0\nu\beta\beta$ will validate the Majorana nature of neutrinos, demonstrate violation of lepton number explaining the observed baryon asymmetry in the universe, and probe new mass generation mechanisms up to the GUT scale. The planned nEXO experiment will search for...
The SCI-CASTER project at the SFU Nuclear Science Laboratory aims to develop position-sensitive ionization chamber detector technologies for precision charged particle measurements. Modern waveform digitization and analysis methods enable this by allowing for the direct application of the Shockley-Ramo theorem to the induced charge signals of the ionization chamber, yielding measurements of...
GANIL/SPIRAL2 presently offers unique opportunities in nuclear physics and in many other fields that arise from not only the provision of low-energy stable beams, fragmentation beams, re-accelerated radioactive species, and recently neutron beams but also from the availability of a wide range of state-of-the-art spectrometers and instrumentation. A few examples of recent highlights will be...
Proof that our Early Solar System (ESS) was irradiated with short-lived radionluclides (SLR's) from an external supernovae is well-evidenced by the fossil presence of $^{26}$Al, $^{41}$Ca, $^{60}$Fe and other SLR's in ancient geologic and meteoritic phases. Many of these SLR's (i.e. $^{26}$Al) find significance as radiometric clocks that record the formation of ESS solids and the timings of...
Mass spectrometry plays an important role in many fields of physics research such as nuclear astrophysics, nuclear structure, and fundamental symmetries. Precise knowledge of masses is critical to these studies. For example, a relative mass precision of $≤10^{-8}$ is required to probe the Standard Model and beyond. This level of precision with radioactive species has been achieved only with...
F. Herwig, P. Denissenkov, J. Issa
Astronomy Research Centre and Department of Physics and Astronomy, Univeristy of Victoria
Recent advances in 3D hydrodynamic simulations of stellar interiors and multi-zone nucleosynthesis calculations have identified specific nuclear reaction rates on unstable species whose experimental determination would significantly reduce uncertainties in predicted...
We will give an overview of recent results from IRIS experiments and discuss future directions enabled by ARIEL.
Studies to probe the internal structure and interactions of nuclei often require precise measurement of radiation emitted from nuclear reactions or decay. Any particular modern nuclear experiment requires unique experimental conditions, creating a demand for versatile radiation detection arrays that can meet a wide variety of experimental needs, with minimal adjustment of physical hardware....
Work has already been done at TRIUMF to directly study ($\alpha$,n) reactions using both DRAGON and EMMA, with the aid of the DEMAND neutron detector array. These reactions are important for understanding both the weak r-process and the s-process. Many of the reactions relevant to the weak r-process involve neutron-rich radioactive nuclei. ARIEL will expand TRIUMF’s rare isotope beam...
TRINAT has at least four existing efforts with opportunities for collaborators and their students. A correlation between spin, beta, and recoil has enhanced sensitivity to time-reversal odd, parity-even, isospin-breaking nucleon-nucleon interactions because of 47K decay's isospin-hindered Fermi component, making it potentially complementary to MORA's more general decays as well as to electric...
Probing shape coexistence in $^{114}$Sn using decay spectroscopy with GRIFFIN
Experiments of highly suppressed or forbidden nuclear decays, like double-gamma decay or nuclear excitation by electron capture, require weeks-long setup and observation times in the TITAN-EBIT, which had been curtailed by the over-subscription of the ISAC era. The results of these experiments have far-reaching implications, including direct probes of electric dipole polarizability and the...
The neutron-rich region surrounding $^{78}$Ni provides a stringent test of nuclear structure far from stability and plays a central role in the astrophysical r-process responsible for the A≈80 abundance peak. As a doubly-magic nucleus, $^{78}$Ni offers a key benchmark for investigating the persistence of the N = 50 shell closure in extremely neutron-rich nuclei. However, direct mass...
The development of ARIEL and other new facilities which expand experimental capabilities to study atomic nuclei triggers the need to advance theories of nuclear structure and reactions. A strong theoretical framework addressing nuclear properties from first-principles is necessary to direct exploration, formulate informative experiments, and interpret the data that ARIEL will grant access...
An optical Time Projection Chamber (oTPC) is proposed for low-energy nuclear physics experiments at TRIUMF/ARIEL, using a Timepix3-based single-photon camera as readout. When charged particles ionize the detector gas, the resulting electron avalanches produce scintillation light captured by an externally mounted camera with an image intensifier — avoiding the complexity of conventional...
Nuclear reactions reveal critical information about nuclear structure and nuclear astrophysics. Some studies, like half-life determinations, are directly relevant to understanding the evolution of nuclear shells, while others have an indirect impact through the production of exotic species to advance the pathway of the rapid-neutron-capture process. The common requirement for these studies at...
