Quantum Chromodynamics predicts a variety of unusual states of matter in which relativity and quantum many-body physics strongly intertwine. Discovering phase transitions between these hottest and densest forms of matter in a laboratory is an unprecedented task. This is the challenge that heavy-ion collision experiments are taking up in the Beam-Energy Scan program at the Relativistic Heavy-Ion Collider (RHIC). What do we know about the phase diagram of QCD matter and how do we learn more? One of the intriguing open questions is the existence and the location of the QCD critical point. Similar critical points are ubiquitous in earthly substances and the phenomena associated with those points are remarkably universal. How can we use this universality to discover the critical point in QCD? It is a nontrivial question in the context of heavy-ion collisions, in large part because of the importance of non-equilibrium dynamics -- the subject of current research.

An increasingly popular method for cancer treatment is proton radiation. Relative to conventional x-ray therapy, proton therapy is advantageous because protons have a limited range, called the Bragg peak (BP), which spares distal normal tissues. Despite its specificity, proton therapy carries some risk. For example, when there is an error in the range and the radiation under- or over-shoots, a drastically different dose is delivered. Due to this risk, a critical need exists to verify the proton range. Due to range uncertainty, proton treatment plans do not take full advantage of the proton's sparing capabilities. This becomes a clinically challenging issue, especially in deep seated tumors. For example, in the Central Nervous System (CNS) there are many organs at risk (OARs) such as the optic nerves, optic chiasm, brainstem, pituitary, and cochlea which abut the target site. Our application is focused on Protoacoustics, is the measurement of acoustic waves generated by clinical proton beams. Measurement of the arrival time of these kHz signals provides a simple and inexpensive method for real-time, in vivo monitoring of proton irradiation. Herein, we propose to develop a protoacoustic method for monitoring proton range in vivo by measuring the time-of-flight (TOF) of the pressure wave. We have discovered a novel role that applies this thermo-acoustic phenomenon to proton range-verification. The successful development of protoacoustic range-verification will provide greater confidence in proton range and consequently allowing smaller margins, improved sparing of healthy tissue and improved patient outcomes to build the foundation for Protoacoustics as a method for changing how proton therapy is monitored with improved targeting and decreased side effects.

As a composer with many writing interests, Frederick Isaac’s preferred mediums include solo piano, classical chamber ensembles, jazz trios, electronic/computer-generated, and vocal. He is just as comfortable working in varying musical styles and languages, from tonal to the avant-garde, as demonstrated by many of his recordings. Isaac’s professional career began as a drummer when he was just sixteen. Currently a college music professor by day, he spent more than two decades producing music for musical theater, church choirs, cocktail bars, jazz ensembles, salsa bands, and ballet companies, both as a pianist/drummer and director. These experiences included stints working for music legend Ben E. King and the Joffrey Ballet of New York. Along with establishing his own label, he is currently included on a few others, including Music Box Classics. In the past several years, his solo piano recordings have gained airplay on college and internet radio stations. These services include Pandora, Sky FM, Calm Radio, MPR, and WKAR FM.

How do you attempt to understand the inner workings of an object when you can’t get close to it? In this Saturday Morning Physics talk, Stephanie Lyons will discuss how scientists at FRIB are working to understand some of the largest objects in the universe, using some of the smallest. In a celebration of the International Year of the Periodic Table, Lyons will take the audience on an adventure to the interior of a star to understand how the elements are made. This talk will dive into understanding the role that nuclear physics plays in the cosmos, and how experiments in the laboratory help answer major scientific questions. This talk is a part of FRIB Saturday Morning Physics.

Core-collapse supernovae mark the death of massive stars and are important sites of nucleosynthesis. The recent decades have brought great progress in our understanding of the supernova mechanism with implications for the production of the elements. In this talk I will discuss open questions and recent progress in understanding supernova nucleosynthesis with particular focus on the supernova neutrino process and the role of multi-dimensional simulations.

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We have developed two cascade arc plasma sources for application to plasma windows for virtual vacuum interfaces. For windowless vacuum–atmosphere separation enabling us to carry out an electron beam welding under atmospheric air condition, a compact arc discharge source having a channel diameter of 3 mm is fabricated, and an atmospheric Ar thermal plasma is generated. On the other hand, to generate a highly charged 238U65+ ion beam with a high intensity and high energy of 10.8 MeV/u in heavy ion accelerators, a He gas charge stripper target has been employed in the Radioactive-Isotope Beam Factory (RIBF) at RIKEN. Using a cascade arc plasma as a virtual window creates an effective vacuum interface to isolate the high pressure He gas cell from the lower pressure vacuum stages. Therefore, we also developed a larger diameter cascade arc discharge apparatus (channel diameter: 8 mm) for application to an alternative differential pumping system. The performances of the two cascade arcs as plasma windows are investigated. The 3-mm arc discharge generates a steep pressure gradient of Ar 100 kPa to 100 Pa through the discharge channel, while the 8-mm discharge apparatus isolates the high-pressure side at 7 kPa from the lower pressure of 54 Pa. Emission spectroscopy of visible and vacuum UV radiation reveals the characteristics of the Ar and He plasmas. Spectral analysis yields a plasma temperature of around 1 eV in both discharges. Stark broadenings of the H- and Ar I lines give an electron density of 6.5×1016 cm–3 for Ar 60 A with a gas flow rate of 1.0 L/min, and 4.7×1013 cm–3 under a He 100-A and 0.45-L/min condition.

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High energy beams of stable nuclei are mostly used as a first step to produce beams of radioactive species. However, there are interesting applications based on the direct usage of the accelerated stable nuclei. We recently performed an experiment at GSI using O-16 beam at an energy of 500 AMeV. We observed the Coulomb breakup into C-12 and He-4 after interaction with a thin lead target. The idea is to constrain the astrophysically very interesting C-12(a,g) rate, which is the time-reversed reaction of the investigated Coulomb breakup. Ion storage rings offer new opportunities to investigate astrophysically interesting reaction in inverse kinematics. We performed proton capture experiments on stable Xe-124 in the energy regime of the gamma-process. The xenon ions were first accelerated to about 100 AMeV then fully stripped, injected into the Experimental Storage Ring at GSI. The actual measurement was performed after the ions were slowed down to 5-10 AMeV using a hydrogen droplet target. Fully stripped ions can have a significantly shorter beta-decay half-life than neutral atoms. The corresponding process is called bound-state beta decay. In the extreme case, nuclei, which are stable under terrestrial conditions, can beta-decay in the inner-most regions of stars. This process can be investigated with ion storage rings. I will review recent accomplishments using stable high-energy beams to infer astrophysically interesting reaction rates. In addition, I will share and discuss ideas for future experiments.

New superheavy nuclei are often identified through their characteristic alpha-decay energies, which requires accurate calculations of Q_alpha values. While many Q_alpha predictions are available, little is known about their uncertainties, and this makes it difficult to carry out extrapolations to as-yet-unknown systems. This work aimed to analyze several models, compare their predictions to available experimental data, and study their performance for the unobserved alpha-decay chains of 296120 and 298120, both of which are of current experimental interest. Using nuclear density functional theory (DFT) with seven Skyrme energy density functionals (EDFs), we evaluated the Q_alpha values for even-even nuclei from Fm to Z = 120. For well-deformed nuclei between Fm and Ds, we find excellent consistency between different model predictions, and a good agreement with experimental results. For transitional nuclei beyond Ds, intermodel differences grow, resulting in an appreciable systematic error. In particular, our models underestimate Q_alpha for the heaviest nucleus 294Og. These results will serve as a benchmark for future, more sophisticated statistical studies based on, for example, Bayesian machine learning techniques.

Fission and nucleosynthesis

The abundance of lithium observed in very young stellar populations is few times larger than the primordial one estimated by recent Planck measurements. Since Lithium is easily destroyed in the stellar interiors, the search for astrophysical sources responsible for the observed lithium over-abundance was a challenge for decades. In this talk I will present the results of an on-going survey dedicated to the study of nova outburst with high-resolution spectrographs at ESO/VLT. In particular, I will concentrate on the recent detection of beryllium-7 in the spectra of recent classical novae. While this finding is a further confirmation of the occurrence of the thermo-nuclear runaway in nova explosions, at same time it implies that classical novae are one of the main factories of lithium in our Galaxy (and other nearby systems).

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