-
Determination of $^{170,172}$Yb($α,n$)$^{173,175}$Hf reaction cross sections in a stacked-target experiment
Authors:
Martin Müller,
Felix Heim,
Yanzhao Wang,
Svenja Wilden,
Andreas Zilges
Abstract:
The ytterbium isotopic chain offers multiple stable isotopes on which cross sections can be measured and insights into the evolution of the $α$ optical-model potential with the neutron-to-proton ratio can be gained. It also includes the $p$ nucleus $^{168}$Yb, the abundance of which is significantly impacted by the $^{164,166}$Yb($α,γ$) reactions. In order to study the $^{170,172}$Yb($α,n$)…
▽ More
The ytterbium isotopic chain offers multiple stable isotopes on which cross sections can be measured and insights into the evolution of the $α$ optical-model potential with the neutron-to-proton ratio can be gained. It also includes the $p$ nucleus $^{168}$Yb, the abundance of which is significantly impacted by the $^{164,166}$Yb($α,γ$) reactions. In order to study the $^{170,172}$Yb($α,n$)$^{173,175}$Hf reaction cross sections and compare them with $^{168}$Yb($α,n$)$^{171}$Hf cross sections, that have already been measured, the activation method was used. During irradiation the targets were arranged in stacks of four to reduce the required irradiation time. The average interaction energy inside each ytterbium layer was determined via Geant4 simulations. A manganese layer was used to verify the simulations by comparing the measured $^{55}$Mn($α,(2)n$)$^{57,58}$Co reaction cross sections to previous results. For irradiation the 10 MV FN tandem accelerator located at the University of Cologne was used and the activation measurement was performed utilizing the Cologne Clover Counting setup. For the $^{170}$Yb($α,n$) reaction seven cross sections at center-of-mass energies between 12.7 and 16.5 MeV were measured. For the $^{172}$Yb($α,n$) reaction six cross sections for center-of-mass energies of 13.1 to 16.5 MeV could be determined with an additional upper limit at E$_{c.m.}$ = 12.3 MeV. Comparisons to theoretical models show that state-of-the-art $α$-optical model potentials are able to reproduce the measured cross sections very well. The ratios of ($α, n$) reaction cross sections in the ytterbium isotopic chain can be accurately reproduced as well.
△ Less
Submitted 9 January, 2026;
originally announced January 2026.
-
Solid Target production for Astrophysical Reasearch: the European target laboratory partnership in ChETEC-INFRA
Authors:
Roberta Spartà,
Alexandra Spiridon,
Rosanna Depalo,
Denise Piatti,
Antonio Massara,
Nicoleta Florea,
Marcel Heine,
Radu-Florin Andrei,
Beyhan Bastin,
Ion Burducea,
Antonio Caciolli,
Matteo Campostrini,
Sandrine Courtin,
Federico Ferraro,
Giovanni Luca Guardo,
Felix Heim,
Decebal Iancu,
Marco La Cognata,
Livio Lamia,
Gaetano Lanzalone,
Eliana Masha,
Paul Mereuta,
Jean Nippert,
Rosario Gianluca Pizzone,
Giuseppe Gabriele Rapisarda
, et al. (6 additional authors not shown)
Abstract:
The joint work of European target laboratories in the ChETEC-INFRA project is presented, to face the new experimental challenges of nuclear astrophysics. In particular, results are presented on innovative targets of 12,13C, 16O, and 19F that were produced, characterized, and, in some cases, tested under beam irradiation. STAR (Solid Targets for Astrophysics Research) is already acting to increase…
▽ More
The joint work of European target laboratories in the ChETEC-INFRA project is presented, to face the new experimental challenges of nuclear astrophysics. In particular, results are presented on innovative targets of 12,13C, 16O, and 19F that were produced, characterized, and, in some cases, tested under beam irradiation. STAR (Solid Targets for Astrophysics Research) is already acting to increase collaboration among laboratories, to achieve shared protocols for target production, and to offer a characterization service to the entire nuclear astrophysics community.
△ Less
Submitted 22 April, 2025;
originally announced April 2025.
-
AircraftVerse: A Large-Scale Multimodal Dataset of Aerial Vehicle Designs
Authors:
Adam D. Cobb,
Anirban Roy,
Daniel Elenius,
F. Michael Heim,
Brian Swenson,
Sydney Whittington,
James D. Walker,
Theodore Bapty,
Joseph Hite,
Karthik Ramani,
Christopher McComb,
Susmit Jha
Abstract:
We present AircraftVerse, a publicly available aerial vehicle design dataset. Aircraft design encompasses different physics domains and, hence, multiple modalities of representation. The evaluation of these cyber-physical system (CPS) designs requires the use of scientific analytical and simulation models ranging from computer-aided design tools for structural and manufacturing analysis, computati…
▽ More
We present AircraftVerse, a publicly available aerial vehicle design dataset. Aircraft design encompasses different physics domains and, hence, multiple modalities of representation. The evaluation of these cyber-physical system (CPS) designs requires the use of scientific analytical and simulation models ranging from computer-aided design tools for structural and manufacturing analysis, computational fluid dynamics tools for drag and lift computation, battery models for energy estimation, and simulation models for flight control and dynamics. AircraftVerse contains 27,714 diverse air vehicle designs - the largest corpus of engineering designs with this level of complexity. Each design comprises the following artifacts: a symbolic design tree describing topology, propulsion subsystem, battery subsystem, and other design details; a STandard for the Exchange of Product (STEP) model data; a 3D CAD design using a stereolithography (STL) file format; a 3D point cloud for the shape of the design; and evaluation results from high fidelity state-of-the-art physics models that characterize performance metrics such as maximum flight distance and hover-time. We also present baseline surrogate models that use different modalities of design representation to predict design performance metrics, which we provide as part of our dataset release. Finally, we discuss the potential impact of this dataset on the use of learning in aircraft design and, more generally, in CPS. AircraftVerse is accompanied by a data card, and it is released under Creative Commons Attribution-ShareAlike (CC BY-SA) license. The dataset is hosted at https://zenodo.org/record/6525446, baseline models and code at https://github.com/SRI-CSL/AircraftVerse, and the dataset description at https://aircraftverse.onrender.com/.
△ Less
Submitted 8 June, 2023;
originally announced June 2023.
-
Experimental techniques to study the $γ$ process for nuclear astrophysics at the Cologne accelerator laboratory
Authors:
F. Heim,
J. Mayer,
M. Müller,
P. Scholz,
M. Weinert,
A. Zilges
Abstract:
The nuclear astrophysics setup at the Institute for Nuclear Physics, University of Cologne, Germany is dedicated to measurements of total and partial cross sections of charged-particle induced reactions at astrophysically relevant energies. These observables are key ingredients for reaction network calculations of various stellar scenarios, and crucial for the understanding of the nucleosynthesis…
▽ More
The nuclear astrophysics setup at the Institute for Nuclear Physics, University of Cologne, Germany is dedicated to measurements of total and partial cross sections of charged-particle induced reactions at astrophysically relevant energies. These observables are key ingredients for reaction network calculations of various stellar scenarios, and crucial for the understanding of the nucleosynthesis of elements. The experiments utilize the high-efficiency $γ$-ray spectrometer HORUS, and the 10 MV FN-Tandem accelerator. An updated target chamber as well as further experimental methods established in the last years will be presented which allow to measure cross sections down to the nb region. The reliability of the measured cross sections is proven by a $^{89}$Y(p,$γ$)$^{90}$Zr commissioning experiment. Additionally, an application for nuclear astrophysics will be presented. The results of a $^{93}$Nb(p,$γ$)$^{94}$Mo experiment will be discussed as well as their deviations compared to formerly reported results.
△ Less
Submitted 27 July, 2020;
originally announced July 2020.
-
Combining γ-ray and particle spectroscopy with SONIC@HORUS
Authors:
S. G. Pickstone,
M. Weinert,
M. Färber,
F. Heim,
E. Hoemann,
J. Mayer,
M. Müscher,
S. Prill,
P. Scholz,
M. Spieker,
V. Vielmetter,
J. Wilhelmy,
A. Zilges
Abstract:
The particle spectrometer SONIC for particle-$γ$ coincidence measurements was commissioned at the Institute for Nuclear Physics in Cologne, Germany. SONIC consists of up to 12 silicon $\mathitΔE$-$E$ telescopes with a total solid angle coverage of 9%, and will complement HORUS, a $γ$-ray spectrometer with 14 HPGe detectors. The combined setup SONIC@HORUS is used to investigate the $γ$-decay behavi…
▽ More
The particle spectrometer SONIC for particle-$γ$ coincidence measurements was commissioned at the Institute for Nuclear Physics in Cologne, Germany. SONIC consists of up to 12 silicon $\mathitΔE$-$E$ telescopes with a total solid angle coverage of 9%, and will complement HORUS, a $γ$-ray spectrometer with 14 HPGe detectors. The combined setup SONIC@HORUS is used to investigate the $γ$-decay behaviour of low-spin states up to the neutron separation threshold excited by light-ion inelastic scattering and transfer reactions using beams provided by a 10 MV FN Tandem accelerator. The particle-$γ$ coincidence method will be presented using data from a $^{92}$Mo(p,p'$γ$) experiment. In a $^{119}$Sn(d,X) experiment, excellent particle identification has been achieved because of the good energy resolution of the silicon detectors of approximately 20 keV. Due to the non-negligible momentum transfer in the reaction, a Doppler correction of the detected $γ$-ray energy has to be performed, using the additional information from measuring the ejectile energy and direction. The high sensitivity of the setup is demonstrated by the results from a $^{94}$Mo(p,p'$γ$) experiment, where small $γ$-decay branching ratios have been deduced.
△ Less
Submitted 19 October, 2017;
originally announced October 2017.