UNPs as HEDP simulators

With the rapid growth and development of potential commercial fusion power plants, the urgency of building a skilled workforce is increasing. Therefore, it is necessary to train and educate early-career scientists and engineers to be able to work for current and future employment in fusion-related fields. In the Inertial Fusion Science and Technology (RISE) Hub, efforts are underway to address this urgency. Specifically in the RISE Hub, we train the next generation of “fusioneers” by involving them in every level of Hub activities. Here, we describe several training, outreach, and educational activities that are led by early-career scientists and engineers, graduate students, and postdoctoral researchers, under the supervision of Hub professionals. These activities educate and train students on key aspects of fusion systems, from the laser driver technologies to the target design, manufacturing, simulation, and validation. In addition, several of these initiatives are being supported by industry partners, national laboratories, and universities, facilitating the transition of knowledge between fusion experts and students. The goals of these outreach efforts led by the RISE Hub are not only to train and educate a skilled workforce but to grow young leaders and broaden their participation in developing commercial fusion power plants.

During the past few years, orbital rocket launches at Vandenberg Space Force Base (VSFB) have increased nearly ten-fold from twenty years ago. As such, there are renewed concerns about the effects of launch noise on threatened and endangered species with critical habitats within VSFB. This talk provides an overview of an interdisciplinary research program to measure and model launch and landing noise on Base and to study responses of two coastal birds, the western snowy plover and the California least tern. Short- and long-term effects are being studied, from changes in vocalization to nest success. This presentation discusses launch noise environments and findings to date.

SpaceX's Starship Super Heavy is the most powerful launch vehicle ever flown, intended to return humans to the moon and reach Mars. After measurements of three test flights (Flights 5, 6, and 9), this paper summarizes the measurements and briefly discusses launch noise and booster flyback boom characteristics. With a planned launch cadence to rival that of the Falcon 9, Starship's noise characterization is critical to determining its impacts and its place relative to other launch vehicles and noise sources. This paper accompanies an Acoustics 2025 plenary talk.

We describe a novel variation of the mirror twin Higgs model in which the color gauge group in both sectors is extended to SU(4)c and spontaneously broken to SU(3)c exclusively in the visible sector. Through this process, the mirror Z2 symmetry is spontaneously broken, allowing for a phenomenologically viable electroweak vacuum alignment. This structure produces interesting collider signatures, including heavy vectors and fermions with fractional electric charges. The twin sector, with unbroken SU(4)c, produces interesting cosmological characteristics, such as the possibility to reduce ∆Neff and stable spin-0 baryons. The enlarged top quark sector required by the extended color gauge symmetry preserves naturalness, with even less tuning than the original twin Higgs in many circumstances.

The use of audible sound for acoustic excitation is commonly employed to assess and monitor structural health, as well as to replicate the acoustic environmental conditions that a structure might experience in use. Achieving the required amplitude and specified spectral shape is essential to meet industry standards. This study aims to implement a sound focusing method called time reversal (TR) to achieve higher amplitude levels compared to simply broadcasting noise. The paper seeks to understand the spatial dependence of focusing long-duration noise signals using TR to increase the spatial extent of the focus. Both one- and two-dimensional measurements are performed and analyzed using TR with noise, alongside traditional noise broadcasting without TR. The variables explored include the density of foci for a given length/area, the density of foci for varying length with a fixed number of foci, and the frequency content and bandwidth of the noise. A use case scenario is presented that utilizes a single-point focus with an upper frequency limit to maintain the desired spectral shape while achieving higher focusing amplitudes.

This paper presents the first study comparing the spectra of a lab-scale afterburning rig operating at a relevant total temperature ratios value of 

 6, typical of Full-Scale (FS) afterburning jets, against Tam's similarity model. The spectral characteristics of FS afterburning jets were successfully reproduced on a lab-scale. Far-field acoustic data at 63 diameters relative to the nozzle exit were used to fit the similarity spectra, with a priority placed on achieving the best fit for the overall shape of the measured spectra while ensuring a smooth growth or decay of the peak frequencies. The transition region, which is delineated by a narrow range of microphone locations from 90° to 107.5°, required a combination of fine-scale similarity spectra (FSS) and large-scale similarity spectra (LSS) to better model both the peaks and roll-offs of the measured spectra. Only LSS was needed to model the spectra near the region of maximum overall sound pressure level radiation, whereas sideline angles only needed FSS. The similarity model was unable to accurately predict the double peaks observed at select angles. Additionally, a mismatch in the high-frequency slope between the similarity model and the measured spectra became apparent outside the region of peak radiation.