Principal Investigator:
Chris Ruiz (TRIUMF) Co-applicants: Alan Chen (McMaster University) Gregory Christian (Saint Mary's University) Barry Davids (TRIUMF) Iris Dillmann (TRIUMF) Falk Herwig (University of Victoria) Rituparna Kanungo (Saint Mary's University) Reiner Krücken (TRIUMF) Dennis Muecher (University of Guelph) Computational Coordinator: Pavel Denissenkov (University of Victoria) |
Nuclear Physics of the Dynamic Origin of the ElementsIn this research proposal we aim to address some of the most compelling questions of how the elements form in stars through nuclear physics processes, whilst simultaneously establishing a graduate training framework at the interface between theoretical and experimental nuclear astrophysics, with a strong inbuilt element of computational nuclear astrophysics. Thus, the research proposal addresses important scientific goals, but also provides a powerful and rich environment for the training of HQP in a unique manner. The proposal will establish a program functioning as a medium-sized research and training network for Canadian nuclear astrophysics graduates, as well as a collaborative hub for Canadian faculty in the field, and as a point of contact for interfacing with similar and umbrella networks in the US and elsewhere internationally
Project supported by NSERC under award SAPPJ-2021-00032
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Program Description
The program aims to gain exceptional return on investment by leveraging the expert skillset of a Canadian- based computational nuclear astrophysicist to guide experimental nuclear physics graduate students in computational projects. This will be done through a comprehensive and integrated framework of tools and research-focused training capacity to allow graduate students to expand their research along the modern frontier of nuclear astrophysics.
The framework consists of individual projects that are aimed at solving specific, novel nucleosynthesis problems via a detailed examination of the nuclear physics and reactions involved. Computational modeling for each problem will guide the integrated cutting-edge experimental program – already in play – based mainly but not exclusively at the ARIEL/ISAC rare isotope facility at TRIUMF. The program seeks to provide the “missing link” in an otherwise fruitful and active collaborative relationship between the nuclear physics and astronomy communities in Canada, by establishing a quickly evolving set of projects run by nuclear physicists. These projects will be intimately tied to recent, ongoing and future experiments using unstable and stable isotopes, but also utilize state-of-the-art computational astrophysics tools under expert supervision.
Traditionally in the field of nuclear astrophysics, important experimental measurements are identified by researchers working in either the astronomy community or theoretical nuclear physics community, but in either case with access to sophisticated stellar codes which they have used and developed over many years. These results are typically published as sensitivity studies and provide a broad, global understanding of the relative importance of various nuclear physics parameters (such as ground state masses or charged-particle reaction rates) to astrophysical observables (such as light curves, spectral evolution, isotopic ratios, abundances etc.), through a set of models. A goal of nuclear astrophysics is to understand the role of individual critical nuclear physics interactions in stellar models so that we can make quantitative theoretical estimates or laboratory measurements of them, reducing or effectively eliminating these as a source of uncertainty in the models. The model results can then be compared with the most modern astronomical observations giving us rich insight into the real phenomena, and adjustments made, or new models composed to better represent the data. Further below we will describe the current state of the astronomical observations, astrophysical computations, and experimental nuclear physics data collection towards this end.
However, this interplay between astrophysicists and nuclear physicists can progress on the timescale of decades: many nuclear quantities considered important but as yet unmeasured were put in place in theoretical or sensitivity studies up to 20 years ago, using the most up-to-date models at the time. Yet in cases where measurements were ultimately made, more modern code versions were then used to specifically evaluate the impact of the measurement on the model results. For example, 1-zone or multi- zone post-processing codes may have been used for the initial sensitivity studies, and after a specific critical nuclear reaction was measured in the laboratory, a hydrodynamic code with an updated network may then have been used to evaluate the resulting range of an astronomical observable.
Nowadays however, state-of-the-art stellar codes such as MESA and NuGrid exist which are really platforms allowing a myriad of stellar phenomena to be simulated under a variety of conditions. These tools are internationally established, and the University of Victoria Astrophysics Group have played a pivotal role in those collaborations. With a bit of training and supervision these tools are accessible at the graduate (or even undergraduate) student level. This provides the possibility of having nuclear physics students do detailed simulations to examine the role of different sets of reactions or other quantities in specific stellar scenarios. An evaluation of the current state of knowledge of those quantities can be performed, and then the student can design, propose and carry-out experiments to attack those uncertainties. This basically outlines the intent of this program: to empower graduate students to perform cutting edge work towards lofty scientific goals, using state-of-the-art tools, at the interface between experimental and theoretical nuclear astrophysics, and to therefore create a new generation of expert HQP in the field.
This training will take place by investigating the nuclear physics processes in new dynamic element formation scenarios. It will identify for these scenarios key nuclear physics measurements that can be performed at a variety of different labs and facilities. The research outcome of these projects will be the foundation for the scientific priorities and directions of the experimental nuclear astrophysics program in Canada for the next decade. As such, this proposal is key to maximize the scientific return of present and future investments in nuclear astrophysics experimental facilities in Canada.
The program aims to gain exceptional return on investment by leveraging the expert skillset of a Canadian- based computational nuclear astrophysicist to guide experimental nuclear physics graduate students in computational projects. This will be done through a comprehensive and integrated framework of tools and research-focused training capacity to allow graduate students to expand their research along the modern frontier of nuclear astrophysics.
The framework consists of individual projects that are aimed at solving specific, novel nucleosynthesis problems via a detailed examination of the nuclear physics and reactions involved. Computational modeling for each problem will guide the integrated cutting-edge experimental program – already in play – based mainly but not exclusively at the ARIEL/ISAC rare isotope facility at TRIUMF. The program seeks to provide the “missing link” in an otherwise fruitful and active collaborative relationship between the nuclear physics and astronomy communities in Canada, by establishing a quickly evolving set of projects run by nuclear physicists. These projects will be intimately tied to recent, ongoing and future experiments using unstable and stable isotopes, but also utilize state-of-the-art computational astrophysics tools under expert supervision.
Traditionally in the field of nuclear astrophysics, important experimental measurements are identified by researchers working in either the astronomy community or theoretical nuclear physics community, but in either case with access to sophisticated stellar codes which they have used and developed over many years. These results are typically published as sensitivity studies and provide a broad, global understanding of the relative importance of various nuclear physics parameters (such as ground state masses or charged-particle reaction rates) to astrophysical observables (such as light curves, spectral evolution, isotopic ratios, abundances etc.), through a set of models. A goal of nuclear astrophysics is to understand the role of individual critical nuclear physics interactions in stellar models so that we can make quantitative theoretical estimates or laboratory measurements of them, reducing or effectively eliminating these as a source of uncertainty in the models. The model results can then be compared with the most modern astronomical observations giving us rich insight into the real phenomena, and adjustments made, or new models composed to better represent the data. Further below we will describe the current state of the astronomical observations, astrophysical computations, and experimental nuclear physics data collection towards this end.
However, this interplay between astrophysicists and nuclear physicists can progress on the timescale of decades: many nuclear quantities considered important but as yet unmeasured were put in place in theoretical or sensitivity studies up to 20 years ago, using the most up-to-date models at the time. Yet in cases where measurements were ultimately made, more modern code versions were then used to specifically evaluate the impact of the measurement on the model results. For example, 1-zone or multi- zone post-processing codes may have been used for the initial sensitivity studies, and after a specific critical nuclear reaction was measured in the laboratory, a hydrodynamic code with an updated network may then have been used to evaluate the resulting range of an astronomical observable.
Nowadays however, state-of-the-art stellar codes such as MESA and NuGrid exist which are really platforms allowing a myriad of stellar phenomena to be simulated under a variety of conditions. These tools are internationally established, and the University of Victoria Astrophysics Group have played a pivotal role in those collaborations. With a bit of training and supervision these tools are accessible at the graduate (or even undergraduate) student level. This provides the possibility of having nuclear physics students do detailed simulations to examine the role of different sets of reactions or other quantities in specific stellar scenarios. An evaluation of the current state of knowledge of those quantities can be performed, and then the student can design, propose and carry-out experiments to attack those uncertainties. This basically outlines the intent of this program: to empower graduate students to perform cutting edge work towards lofty scientific goals, using state-of-the-art tools, at the interface between experimental and theoretical nuclear astrophysics, and to therefore create a new generation of expert HQP in the field.
This training will take place by investigating the nuclear physics processes in new dynamic element formation scenarios. It will identify for these scenarios key nuclear physics measurements that can be performed at a variety of different labs and facilities. The research outcome of these projects will be the foundation for the scientific priorities and directions of the experimental nuclear astrophysics program in Canada for the next decade. As such, this proposal is key to maximize the scientific return of present and future investments in nuclear astrophysics experimental facilities in Canada.