Introduction to neutrino astronomy

neutrino flux

Energy dependence of the neutrino fluxes produced by the different nuclear processes in the Sun

Andrea Gallo Rosso, Carlo Mascaretti, Andrea Palladino, Francesco Vissani
This writeup is an introduction to neutrino astronomy, addressed to astronomers and written by astroparticle physicists. While the focus is on achievements and goals in neutrino astronomy, rather than on the aspects connected to particle physics, we will introduce the particle physics concepts needed to appreciate those aspects that depend on the peculiarity of the neutrinos. The detailed layout is as follows: In Sect.~1, we introduce the neutrinos, examine their interactions, and present neutrino detectors and telescopes. In Sect.~2, we discuss solar neutrinos, that have been detected and are matter of intense (theoretical and experimental) studies. In Sect.~3, we focus on supernova neutrinos, that inform us on a very dramatic astrophysical event and can tell us a lot on the phenomenon of gravitational collapse. In Sect.~4, we discuss the highest energy neutrinos, a very recent and lively research field. In Sect.~5, we review the phenomenon of neutrino oscillations and assess its relevance for neutrino astronomy. Finally, we offer a brief overall assessment and a summary in Sect.~6. The material is selected – i.e., not all achievements are reviewed – and furthermore it is kept to an introductory level, but efforts are made to highlight current research issues. In order to help the beginner, we prefer to limit the list of references, opting whenever possible for review works and books.


A short walk through the physics of neutron stars

A schematic cross section of a neutron star illustrating the various regions discussed in the text. The different regions shown are not drawn on scale.

Isaac Vidana
In this work we shortly review several aspects of the physics of neutron stars. After the introduction we present a brief historical overview of the idea of neutron stars as well as of the theoretical and observational developments that followed it from the mid 1930s to the present. Then, we review few aspects of their observation discussing, in particular, the different types of telescopes that are used, the many astrophysical manifestations of these objects, and several observables such as masses, radii or gravitational waves. Finally, we briefly summarize some of theoretical issues like their composition, structure equations, equation of state, and neutrino emission and cooling.

Applications of Nuclear Physics

Anna C. Hayes
Today the applications of nuclear physics span a very broad range of topics and fields. This review discusses a number of aspects of these applications, including selected topics and concepts in nuclear reactor physics, nuclear fusion, nuclear non-proliferation, nuclear-geophysics, and nuclear medicine. The review begins with a historic summary of the early years in applied nuclear physics, with an emphasis on the huge developments that took place around the time of World War II, and that underlie the physics involved in designs of nuclear explosions, controlled nuclear energy, and nuclear fusion.
The review then moves to focus on modern applications of these concepts, including the basic concepts and diagnostics developed for the forensics of nuclear explosions, the nuclear diagnostics at the National Ignition Facility, nuclear reactor safeguards, and the detection of nuclear material production and trafficking. The review also summarizes recent developments in nuclear geophysics and nuclear medicine. The nuclear geophysics areas discussed include geo-chronology, nuclear logging for industry, the Oklo reactor, and geo-neutrinos.
The section on nuclear medicine summarizes the critical advances in nuclear imaging, including PET and SPECT imaging, targeted radionuclide therapy, and the nuclear physics of medical isotope production. Each subfield discussed requires a review article onto itself, which is not the intention of the current review. Rather, the current review is intended for readers who wish to get a broad understanding of applied nuclear physics.

Accelerator on a Chip

Could tiny chips no bigger than grains of rice do the job of a huge particle accelerator? At full potential, a series of these “accelerators on a chip” could boost electrons to the same high energies achieved in SLAC National Accelerator Laboratory’s 2-mile linear accelerator in a distance of just 100 feet. This could make accelerators a lot smaller and more affordable.

The Gordon and Betty Moore Foundation has awarded $13.5 million to an international collaboration led by Stanford University, to develop a working prototype of such an accelerator over the next five years. SLAC and two other national labs provide key in-kind contributions in support of this expansive university effort.

Here’s how “accelerator on a chip” works: Electrons enter the chip and travel through a microscopic tunnel that has tiny ridges carved into its walls. When scientists shine an infrared laser on the chip, the light interacts with those ridges and produces an electrical field that boosts the energy of the passing electrons. In experiments at SLAC, the chip achieved an acceleration gradient, or energy boost over a given distance, roughly 10 times higher than the SLAC linear accelerator can provide.

There’s a lot of work to do to make this technology practical for real-world use. For instance, creating a full-fledged tabletop accelerator will require a more compact way to get electrons up to speed before they enter the chip; the Moore Foundation’s funding will help scientists work on that, and ideally create a prototype the size of a shoebox.

On the plus side, the accelerator on a chip uses commercial lasers and can be manufactured with low-cost, mass-production techniques.

Scientists think a series of these tiny chips could greatly reduce the size and cost of particle accelerators for a variety of applications. For example, the technology could help make compact low-cost accelerators and X-ray devices for security scanning, medicine, biology and materials science. Small, portable X-ray sources could improve medical care for people injured in combat and reduce the cost of medical imaging in hospitals.