bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical analysis and experimental preparation of nanodiamond yttrium vacancy color center
Authors: Tan Xin , Wang Hao , Li Minjie , Wang Jian , Sun Shiyang , Meng Keke , Ren Yuan , Qi Hui 
Published: January 2023

Abstract
This study conducts a theoretical analysis on the stable structure, charge transfer, energy level transition, and electronic structure of a diamond yttrium vacancy color center. The color center in a diamond is very important as a single photon source material for quantum information processing technology and applications, such as temperature sensors, solid-state quantum systems, photonics, lighting, imaging technology, and biomedicine. Nanodiamond yttrium vacancy color centers are prepared using the solid substitution method with physical vapor deposition and microwave plasma chemical vapor deposition equipment. The density functional theory (DFT) is used to analyze the stability, electronic structure, and co-doping of N, Si, and O on the related defect structure of a rare Earth element yttrium-doped diamond using first-principle calculations, demonstrating consistency with the experimental results. The research shows that the fluorescence wavelength of an yttrium vacancy color center measured using the solid substitution method is 701.2 nm, which is located in the red region. The system is most stable when a Y atom replaces a carbon atom and there are two vacancies around it. The zero-phonon line of the diamond YV2 defect is predicted to be 708.855 nm. Additionally, the influence doping is analyzed with N, Si, and O atoms. An yttrium-doped diamond emits light in the visible light region, which provides a theoretical basis for the application of diamond yttrium vacancy color centers.
A peculiarity of nuclear flow in the stellar CNO cycle with energetic particles
Authors: Voronchev V T 
Published: January 2023

Abstract
A peculiarity of the stellar carbon-nitrogen-oxygen (CNO) cycle caused by MeV α-particles and protons generated in exoergic nuclear processes is analyzed. The main parameters of these particles and suprathermal reactions induced by them in a stellar core are calculated. It is shown that these reactions can trigger an abnormal nuclear flow in the second branch of the stellar CNO cycle. A conjecture is made that the phenomenon is of a general nature and can manifest in various stars at non-exploding stages of their evolution. The influence of the abnormal flow on some CNO characteristics is demonstrated.
Multi-messenger high-energy signatures of decaying dark matter and the effect of background light
Authors: Skrzypek B. , Chianese M. , Argüelles C.A. 
Published: January 2023

Abstract
The IceCube Neutrino Observatory at the South Pole has measured astrophysical neutrinos
using through-going and starting events in the TeV to PeV energy range. The origin of these
astrophysical neutrinos is still largely unresolved, and among their potential sources could be
dark matter decay. Measurements of the astrophysical flux using muon neutrinos are in slight
tension with starting event measurements. This tension is driven by an excess observed in the
energy range of 40–200 TeV with respect to the through-going expectation. Previous works have
considered the possibility that this excess may be due to heavy dark matter decay and have placed
constraints using gamma-ray and neutrino data. However, these constraints are not without
caveats, since they rely on the modeling of the astrophysical neutrino flux and the sources of
gamma-ray emission. In this work, we derive background-agnostic galactic and extragalactic
constraints on decaying dark matter by considering Tibet-ASγ data, Fermi-LAT diffuse data,
and the IceCube high-energy starting event sample. For the gamma-ray limits, we investigate the
uncertainties on secondary emission from electromagnetic cascades during propagation arising from
the unknown intensity of the extragalactic background light. We find that such uncertainties
amount to a variation of up to ∼ 55% in the gamma-ray limits derived with extragalactic
data. Our results imply that a significant fraction of the astrophysical neutrino flux could be
due to dark matter and that ruling it out depends on the assumptions on the gamma-ray and neutrino
background. The latter depends on the yet unidentified sources.
Validation of 2D
Te
and
ne
measurements made with Helium imaging spectroscopy in the volume of the TCV divertor
Authors: Linehan B.L. , Perek A. , Duval B.P. , Bagnato F. , Blanchard P. , Colandrea C. , De Oliveira H. , Février O. , Flom E. , Gorno S. , Goto M. , Marmar E. , Martinelli L. , Mathews A. , Muñoz-Burgos J. , Mykytchuk D. , Offeddu N. , Oliveira D.S. , Reimerdes H. , Reiter D. , Schmitz O. , Terry J.L. , Theiler C. , Tsui C.K. , Vincent B. , Wijkamp T. , Wüthrich C. , Zholobenko W. ,   the TCV Team
Published: January 2023

Abstract
Multi-spectral imaging of helium atomic emission (HeMSI) has been used to create 2D poloidal maps of

T

e

and

n

e

in TCV’s divertor. To achieve these measurements, TCV’s MANTIS multispectral cameras (Perek et al 2019 Rev. Sci. Instrum.
90 123514) simultaneously imaged four He I lines (two singlet and two triplet) and a He II line (468 nm) from passively present He and He+. The images, which were absolutely calibrated and covered the whole divertor region, were inverted through the assumption of toroidal symmetry to create emissivity profiles and, consequently, line-ratio profiles. A collisional-radiative model (CRM) was applied to the line-ratio profiles to produce 2D poloidal maps of

T

e

and

n

e

. The collisional-radiative modeling was accomplished with the Goto helium CRM code (Zholobenko et al 2018 Nucl. Fusion
58 126006, Zholobenko et al 2018 Technical Report, Goto 2003 J. Quant. Spectrosc. Radiat. Transfer
76 331–44) which accounts for electron-impact excitation (EIE) and deexcitation, and electron–ion recombination (EIR) with

He

+

. The HeMSI

T

e

and

n

e

measurements were compared with co-local Thomson scattering measurements. The two sets of measurements exhibited good agreement for ionizing plasmas:

(

5

eV

⩽

T

e

⩽
60

eV

, and

2
×

10

18

m

−
3

⩽

n

e

⩽
3
×

10

19

m

−
3

)

in the case of majority helium plasmas, and

(

10

eV

⩽

T

e

⩽
40

eV

,

2
×

10

18

m

−
3

⩽

n

e

⩽
3
×

10

19

m

−
3

)

in the case of majority deuterium plasmas. However, there were instances where HeMSI measurements diverged from Thomson scattering. When

T

e

⩽
10

eV

in majority deuterium plasmas, HeMSI deduced inaccurately high values of

T

e

. This disagreement cannot be rectified within the CRM’s EIE and EIR framework. Second, on sporadic occasions within the private flux region, HeMSI produced erroneously high measurements of

n

e

. Multi-spectral imaging of Helium emission has been demonstrated to produce accurate 2D poloidal maps of

T

e

and

n

e

within the divertor of a tokamak for plasma conditions relevant to contemporary divertor studies.
Modeling of crowd groups with an extended social field model
Authors: Yu Bin 
Published: January 2023

Abstract
A social field model is extended by adding supports of simulations of crowd group related dynamics such as group cohesion, back-tracking, etc. A computational implementation combining heterogeneous computing and multi-threading technologies is developed to integrate the proposed extension into a heterogeneous computing framework. Hence modeling of group related dynamics can be accomplished in a very efficient manner. In the section of numerical experiments, the extended model is firstly validated with a set of practical data. Results show that the simulated evacuation time matches the practical one quite well. Then a study of fundamental diagrams is expanded with considerations of crowd groups. It is shown that the impact of crowd groups mainly happens in the regime of low densities and would become insignificant in the regime of high densities.
Replica analysis of the lattice-gas restricted Boltzmann machine partition function
Authors: Hoyle David C 
Published: January 2023

Abstract
We study the expectation value of the logarithm of the partition function of large binary-to-binary lattice-gas restricted Boltzmann machines (RBMs) within a replica-symmetric ansatz, averaging over the disorder represented by the parameters of the RBM Hamiltonian. Averaging over the Hamiltonian parameters is done with a diagonal covariance matrix. Due to the diagonal form of the parameter covariance matrix not being preserved under the isomorphism between the Ising and lattice-gas forms of the RBM, we find differences in the behaviour of the quenched log partition function of the lattice-gas RBM compared to that of the Ising RBM form usually studied. We obtain explicit expressions for the expectation and variance of the lattice-gas RBM log partition function per node in the thermodynamic limit. We also obtain explicit expressions for the leading order finite size correction to the expected log partition function per node, and the threshold for the stability of the replica-symmetric approximation. We show that the stability threshold of the replica-symmetric approximation is equivalent, in the thermodynamic limit, to the stability threshold of a recent message-passing algorithm used to construct a mean-field Bethe approximation to the RBM free energy. Given the replica-symmetry assumption breaks down as the level of disorder in the spin-spin couplings increases, we obtain asymptotic expansions, in terms of the variance controlling this disorder, for the replica-symmetric log partition function and the replica-symmetric stability threshold. We confirm the various results derived using simulation.
Performance of neutron-irradiated 4H-silicon carbide diodes subjected to alpha radiation
Authors: Gaggl P. , Gsponer A. , Thalmeier R. , Waid S. , Pellegrini G. , Godignon P. , Rafí J.M. , Bergauer T. 
Published: January 2023

Abstract
The unique electrical and material properties of 4H-silicon-carbide (4H-SiC) make it a promising candidate material for high rate particle detectors. In contrast to the ubiquitously used silicon (Si), 4H-SiC offers a higher carrier saturation velocity and larger breakdown voltage, enabling a high intrinsic time resolution and mitigating pile-up effects. Additionally, as radiation hardness requirements grow more demanding in the context of future high luminosity high energy physics experiments, wide-bandgap materials such as 4H-SiC could offer better performance due to low dark currents and higher atomic displacement thresholds. In this work, the detector performance of 50 µm thick 4H-SiC p-in-n planar pad sensors was investigated at room temperature, using an 241Am alpha source at reverse biases of up to 1100 V. Samples subjected to neutron irradiation with fluences of up to 1 × 1016 neq/cm2 were included in the study in order to quantify the radiation hardness properties of 4H-SiC. A calibration of the absolute number of collected charges was performed using a GATE simulation. The obtained results are compared to previously performed UV transient current technique (TCT) studies. Samples exhibit a drop in charge collection efficiency (CCE) with increasing irradiation fluence, partially compensated at high reverse bias voltages far above full depletion voltage. At fluences of 5 × 1014 neq/cm2 and 1 × 1015 neq/cm2, CCEs of 64 % and 51 % are obtained, decreasing to 15 % at 5 × 1015 neq/cm2. A plateau of the collected charges is observed in accordance with the depletion of the volume the alpha particles penetrate for an unirradiated reference detector. For the neutron-irradiated samples, such a plateau only becomes apparent at higher reverse bias, roughly 600 V and 900 V for neutron fluences of 5 × 1014 neq/cm2 and 1 × 1015 neq/cm2. For the highest investigated fluence, CCE behaves almost linearly with increasing reverse bias. Compared to UV-TCT measurements, the reverse bias required to deplete a sensitive volume covering full energy deposition is lower, due to the small penetration depth of the alpha particles. At the highest reverse bias, the measured CCE values agree well with earlier UV-TCT studies, with discrepancies between 1% and 5%.
Production and testing of the powerboard for ATLAS ITk Strip barrel modules
Authors: Haber C. , Heim T. , Kelly S. , Krizka K. , Zhang Z. 
Published: January 2023

Abstract
The upgrade of the ATLAS ITk strips detector for HL-LHC will employ a custom PCB (powerboard) for on-module DC-DC conversion, HV switching, and monitoring. Production of about 14100 of such PCBs with high reliability is a big challenge. This paper will present the production procedure and quality control (QC) testing system for the powerboards to be installed on ITk Strip barrel modules. During production, about 150 powerboards will be produced every week. Each powerboard will need to pass QC tests before they are assembled to module. The QC tests include thermal cycling between −35 °C and 40 °C, soak test (continuous running of DC-DC converter at high load at 20 °C), and basic functionality and characterization electrical tests of the low voltage (LV), high voltage (HV), and monitoring functions of the powerboard. A custom QC test system is described, which is based on a reusable PCB (active board) with all testing circuits, a one-time powerboard carrier card, and a Z-turn SoC board which hosts and runs the testing program. The production procedure and QC test system has been tested with 400 powerboards during pre-production, and the system has been proven ready for production with the desired testing program, speed, safety, and cost. Performance and typical failures of powerboards observed during the QC test of pre-production powerboards is also presented.
Development of a Stitched Monolithic Pixel Sensor prototype (MOSS chip) towards the ITS3 upgrade of the ALICE Inner Tracking system
Authors: Vicente Leitao P. , Aglieri Rinella G. , Bugiel S. , Cecconi L. , de Melo J.L.A. , De Robertis G. , Deng W. , Dorda Martin A. , Dorosz P. , Fang X. , Gajanana D. , Gromov V. , Hodges A. , Hong G.H. , Kremastiotis I. , Kugathasan T. , Loddo F. , Marras D. , Matthew S. , Morel F. , Piro F. , Pulli A. , Sedgwick I. , Snoeys W. , Soudier J. , Valin I. , Yelkenci A. 
Published: January 2023

Abstract
The MOnolithic Stitched Sensor (MOSS) is a development prototype chip towards the ITS3 vertexing detector for the ALICE experiment at the LHC. Designed using a 65 nm CMOS Imaging technology, it aims at profiting from the stitching technique to construct a single-die monolithic pixel detector of 1.4 cm × 26 cm. The MOSS prototype is one of the prototypes developed within the CERN-EP R&D framework to learn how to make stitched wafer-scale sensors with satisfactory yield. This contribution will describe some of the design challenges of a stitched pixel sensor and the techniques adopted during the development of this prototype.
Software tools for hybrid quality control for the CMS Outer Tracker Phase-2 Upgrade
Authors: Mateos Domínguez I. , Blanchot G. , Chatagnon P. , Cooperstein S. , Di Mattia A. , Honma A. , Klein K. , Kovacs M. , La Rosa A. , Makarenko I. , Otarid Y. , Pauls A. , Pissaki Z. , Schleidweiler K. , Seif El Nasr S. , Zografos A. 
Published: January 2023

Abstract
Fifty thousand hybrid circuits of five different types will be manufactured for the Phase-2 Upgrade of the CMS Outer Tracker. These circuits must undergo a strict quality control process, composed of functional testing and visual inspection, before they can be assembled into modules. The hybrids will be functionally tested first at the manufacturing site. Afterwards, they will be visually inspected and functionally tested again at CERN or at collaborating institutes. Results from these processes will be stored in the CMS production database. This paper presents the software tools developed to carry out these tasks.
A radiation hard bandgap voltage reference for the ARCADIA project
Authors: Traversi G. , Falchieri D. , Gaioni L. , Manghisoni M. , Pezzoli M. , Ratti L. , Re V. 
Published: January 2023

Abstract
This work presents the design and characterization results of a radiation hard bandgap reference circuit fabricated in a 110 nm CMOS technology for the Main Demonstrator chip of the ARCADIA project. The design, based on a current-mode approach in order to be able to output a smaller than 1.2 V reference voltage, employs diode-connected MOSFETs instead of BJTs to enhance the radiation hardness and a second amplifier to improve the current mirror of the output branch and therefore the line regulation of the circuit. This paper describes the features of the circuit and its measured results.
Studies of event burst phenomenon with SiPMs in liquid nitrogen
Authors: Tsang T. , Chen H. , Gao S. , Giacomini G. , Radeka V. , Rescia S. 
Published: January 2023

AbstractSilicon photomultiplier (SiPM) are used to collect scintillation photons in many cryogenic noble liquid detectors deployed around the world, such as DarkSide, nEXO, MEGII, ProtoDUNE and DUNE. An event burst phenomenon was observed during routine characterization on many models of SiPMs operated in liquid nitrogen. These bursts of consecutive pulses are initiated by an intense dark photoelectron pulse with an event rate much lower than the time-uncorrelated thermal dark pulse. Although the rate of these burst events is very low, it can potentially compromise some dedicated rare physics event searches which are also anticipated to be of extremely low rate. Here, we systematically studied the behavior of the event burst phenomenon and identified the probable cause of the phenomenon. This investigation is important for the selection of SiPMs for use in noble liquid detectors, high energy physics experiments, and industrial applications where SiPMs are used in cryogenic environment.
A dedicated and versatile system for testing the radiation hardness of various integrated circuits
Authors: Placinta V.M. , Cojocariu L.N. , Maciuc F. 
Published: January 2023

Abstract
This work describes the architecture of a versatile system that is dedicated to the testing of various integrated circuits in radiation (e.g., ASICs, FPGAs). The system powers the device under test remotely. It monitors and reads out in real time various parameters, like: power consumption, voltage and current (with resolution of 100 µV and 100 µA, respectively), specific operational parameters of the device under test and its package temperature. A key feature of this system is its multi-channel and remote power supply capabilities, used to power the device under test. It embeds built-in features to detect and record single-event latch-ups, single event upsets and to monitor total ionizing dose cumulative effects. A graphical user interface allows the user to connect and to control the entire system through a dedicated ethernet interface from a safe location zone, and record to disk measurements data.
Unified Modulation Pattern Analysis (UMPA) algorithm for 1D sensitive X-ray phase contrast imaging techniques
Authors: Di Trapani V. , Brombal L. , De Marco F. , Dreossi D. , Thibault P. 
Published: January 2023

AbstractX-ray phase contrast imaging (XPCI) techniques are sensitive to refraction (differential-phase) and small-angle X-ray scattering (dark-field) signals, not measurable with conventional absorption imaging techniques. Among XPCI techniques, edge illumination (EI), grating interferometry (GI), and speckle-based imaging (SBI) make use of wavefront markers, such as absorbing masks with periodical apertures or random diffusers, to encode refraction and dark-field signals induced by the sample. The Unified Modulated Pattern Analysis (UMPA) provides an algorithmic solution to extract the transmission, refraction, and dark-field images from EI, GI, and SBI datasets where the wavefront marker is directly resolved by the employed detection system. In its original implementation, UMPA has been designed for XPCI techniques sensitive to refractions along two axes. This work presents a modified version of the algorithm to extend its applicability to all the existing XPCI techniques that use wavefront markers with sensitivity to refraction limited along one direction (UMPA-1D). The algorithm, written in C++ and Cython and parallelized with OpenMP, enables fast reconstruction times that are particularly convenient for large tomographic datasets. The validity of the UMPA-1D has been demonstrated using both simulated images and real acquisitions with an EI setup in beam-tracking mode.
Radiation-tolerant all-digital clock generators for HEP applications
Authors: Biereigel S. , Kulis S. , Mendes E. , Hazell P. , Moreira P. , Prinzie J. 
Published: January 2023

Abstract
The emergence of high-precision timing systems in High Energy Physics motivates new developments in the domain of clock generation and distribution. Particularly, when considering the challenges arising from adopting advanced deep-submicron CMOS technology nodes, all-digital PLL and clock and data recovery (CDR) architectures constitute a promising option for future high energy physics (HEP) experiments. Both LC oscillator and ring oscillator-based all-digital PLL/CDR blocks for front-end ASICs were studied, designed, manufactured and characterized. Their design, the hardening considerations, as well as the performance obtained with these circuits are presented in this article.
The upgraded quench protection system for main quadrupoles in the LHC
Authors: Skoczeń Andrzej , Steckert Jens , Spasic Jelena , Blasco Serrano Daniel , Mundra Surbhi , Pridii Tetiana 
Published: January 2023

Abstract
The protection of superconducting magnets is a very important issue and demanding challenge in the LHC and other superconducting accelerating facilities. The quench phenomenon can destroy components of the accelerator, and therefore this digital system was designed, implemented, tested, and installed near each superconducting magnet in the LHC tunnel. The quench detection principle relies on the extraction of resistive voltage by compensation of the inductive part of the voltage. This article presents briefly the architecture applied to the design and the validation of the FPGA-based quench detector for the main quadrupoles of the LHC. The article focusses on digital design with the use of FPGA by VHDL coding and on the verification by simulation. The design is a replacement for the old detection system.
Automated real-space lattice extraction for atomic force microscopy images
Authors: Corrias Marco , Papa Lorenzo , Sokolović Igor , Birschitzky Viktor , Gorfer Alexander , Setvin Martin , Schmid Michael , Diebold Ulrike , Reticcioli Michele , Franchini Cesare 
Published: January 2023

Abstract
Analyzing atomically resolved images is a time-consuming process requiring solid experience and substantial human intervention. In addition, the acquired images contain a large amount of information such as crystal structure, presence and distribution of defects, and formation of domains, which need to be resolved to understand a material’s surface structure. Therefore, machine learning techniques have been applied in scanning probe and electron microscopies during the last years, aiming for automatized and efficient image analysis. This work introduces a free and open source tool (AiSurf: Automated Identification of Surface Images) developed to inspect atomically resolved images via scale-invariant feature transform and clustering algorithms. AiSurf extracts primitive lattice vectors, unit cells, and structural distortions from the original image, with no pre-assumption on the lattice and minimal user intervention. The method is applied to various atomically resolved non-contact atomic force microscopy images of selected surfaces with different levels of complexity: anatase TiO2(101), oxygen deficient rutile TiO2(110) with and without CO adsorbates, SrTiO3(001) with Sr vacancies and graphene with C vacancies. The code delivers excellent results and is tested against atom misclassification and artifacts, thereby facilitating the interpretation of scanning probe microscopy images.