The Influence of Near-Threshold States on Nuclear Observables
22 January 2025 - 4:10 PM
1300 FRIB Laboratory and Online via Zoom
Argonne National Laboratory
Calem Hoffman
Show/Hide Abstract
One method of pursuit in our search for a more complete description of the spectroscopic properties of nuclei is through the isolation of specific or well-developed mechanisms. In the present work the characteristics of a weakly-bound nuclear single-particle orbital wave function, defined by its approach to the confining threshold, have been shown to be rooted within various nuclear phenomena. Most notably, the role of this geometric or so-called weak-binding behavior has been found to impact our descriptions of evolving single-particle orbitals, the presence or impact of 'bubble' nuclei, the locations of the particle driplines, and the origins of nuclear halo states. Future directions building upon and complementing this new insight will also be discussed.
An SRF cavity is used to accelerate a beam of particles in a linac. In order to accelerate the beam efficiently and without interruptions the cavity must be tuned to the nominal frequency. During operation an SRF cavity experiences a wide variety of vibrations which perturb the cavity frequency. Many design efforts are implemented to mitigate the vibrations on the cavity and they result in a reduction. However, not all the vibrations can be eliminated and some while reduced are still present. In this talk a review of the vibration sources in LCLS-II and LCLS-II-HE cryomodules will be discussed. Cavity tuners are used to mitigate the vibrations that couldnât be eliminated. The components of the tuner are discussed. Finally, a discussion on some resonance control algorithms will be done. Resonance control algorithms for both pulsed and continuous wave (CW) will be presented.
Concert program:
1. Groovin high-John "Dizzy" Gilespie
2. Maroon-Jackson Hacias
3. I want to talk about you-Billy Eckstine
4. The night has a thousand eyes-Buddy Bernier/Jerry Brainin
5. In the pale glow of night-Jackson Hacias
6. Yes or no-Wayne Shorter
7. Galapagos-Jackson Hacias
Particle, nuclear, and astrophysics experiments are producing massive amounts of data to answer fundamental questions about the basic constituents of our universe. While researchers in these areas have been using advanced data science tools for decades, modern machine learning has introduced a paradigm shift whereby data can be directly analyzed holistically without first compressing it into a more manageable and human understandable format. How will the machines help us explore the unknown? Can they be trusted to give us the right answers? Iâll attempt to address these questions and others with a talk about the use of modern machine learning, including generative AI, in the study of fundamental interactions.
The Electron Ion Collider Project will upgrade the Brookhaven National Laboratory Relativistic Heavy Ion Collider complex to collide highly polarized (>70%) electrons and ions, from deuterons to the heaviest stable nuclei, with center-of-mass energies spanning 20 to 100 GeV at luminosities of 1033-1034 cm-2 s-1. To achieve these goals a set of 4 unique superconducting radio frequency systems are required for beam acceleration, storage, and crabbing. This seminar will briefly review the EIC as it relates to the radio-frequency systems, and then focus on the high-intensity beam interactions with the superconducting radio-frequency (SRF) systems. Examples will include the 800 kW 2.0 K SRF cryomodules necessary for storing up to 2.5 A electron beams with ~ 10 MW of continuous power loss, 25 mrad crossing angle crab cavities, and the state-of-the-art damping required for all of the superconducting cavities.
The Nuclear Science Summer School (NS3) is a summer school that introduces undergraduate student participants to the fields of nuclear science and nuclear astrophysics. NS3 is hosted by FRIB on the campus of Michigan State University (MSU). The school will offer lectures and activities covering selected nuclear science and astrophysics topics.
