bluuebunny/crossref_metadata_2025_split huggingface dataset:
Miniaturized scintillator dosimeter for small field radiation therapy
Authors: Gonod Mathieu , Chacon Avila Carlos , Angel Suarez Miguel , Crouzilles Julien , Laskri Samir , Vinchant Jean-François , Aubignac Léone , Grosjean Thierry 
Published: May 2021

Abstract
The concept of a miniaturized inorganic scintillator detector is demonstrated in the analysis of the small static photon fields used in external radiation therapy. Such a detector is constituted by a 0.25 mm diameter and 0.48 mm long inorganic scintillating cell (1.6 × 10−5 cm3 detection volume) efficiently coupled to a narrow 125 μm diameter silica optical fiber using a tiny photonic interface (an optical antenna). The response of our miniaturized scintillator detector (MSD) under 6 MV bremsstrahlung beam of various sizes (from 1 × 1 cm2 to 4 × 4 cm2) is compared to that of two high resolution reference probes, namely, a micro-diamond detector and a dedicated silicon diode. The spurious Cerenkov signal transmitted through our bare detector is rejected with a basic spectral filtering. The MSD shows a linear response regarding the dose, a repeatability within 0.1% and a radial directional dependence of 0.36% (standard deviations). Beam profiling at 5 cm depth with the MSD and the micro-diamond detector shows a mismatch in the measurement of the full widths at 80% and 50% of the maximum which does not exceed 0.25 mm. The same difference range is found between the micro-diamond detector and a silicon diode. The deviation of the percentage depth dose between the MSD and micro-diamond detector remains below 2.3% within the first fifteen centimeters of the decay region for field sizes of 1 × 1 cm2, 2 × 2 cm2 and 3 × 3 cm2 (0.76% between the silicon diode and the micro-diamond in the same field range). The 2D dose mapping of a 0.6 × 0.6 cm2 photon field evidences the strong 3D character of the radiation-matter interaction in small photon field regime. From a beam-probe convolution theory, we predict that our probe overestimates the beam width by 0.06%, making our detector a right compromise between high resolution, compactness, flexibility and ease of use. The MSD overcomes problem of volume averaging, stem effects, and despite its water non-equivalence it is expected to minimize electron fluence perturbation due to its extreme compactness. Such a detector thus has the potential to become a valuable dose verification tool in small field radiation therapy, and by extension in Brachytherapy, FLASH-radiotherapy and microbeam radiation therapy.
Model based computation of electromagnetic forces in magnetic confinement toroidal devices by using magnetic measurements
Authors: Abate D , Marchiori G , Berton G , Bonotto M , Cordaro L , Grando L , Bettini P 
Published: May 2021

Abstract
In this paper we present a method to compute spatial and time evolution of electromagnetic forces in magnetic confinement fusion devices based on a combination of signal analysis of magnetic measurements with a simple electromagnetic modelling. The method allows analyzing the whole plasma discharge including fast transient phenomena such as fast terminations or disruptions. It has been tested and verified on RFX-mod, an experiment equipped with a non-continuous toroidal passive stabilizing shell, but it can be applied to cases with continuous wall such as tokamak devices, as well. An experimental plasma discharge, with a fast termination phenomenon at the end of the flat-top phase, has been analyzed and the related forces have been computed by using two different sets of data: synthetic magnetic field measurements provided by ANSYS simulation and real experimental ones. The results are in good agreement in all the phases of the plasma discharge. Moreover, because of the very low-computational requirements, it is shown that the presented method can be used as a tool for real-time monitoring of the electromagnetic forces on the shell to be integrated in the protection system of the future RFX-mod2 experiment.
Numerical simulation for bio-convective flow of Sutterby nanofluid by a rotating disk
Authors: Abuzaid Dina , Ullah Malik Zaka 
Published: May 2021

Abstract
Nanofluids play a vital role in the improvement of our practical life. The potential usage of nanomaterials in different applications such as oil recovery, refrigeration systems, a freeze of electrical components in computers, development of liquid displays, cooling spirals, mechanical engineering, electrical engineering, heat storage devices and biotechnology. Swimming microorganisms have a crucial role in various areas of life, such as medicines, bioengineering, biofuels and food processing. Microorganisms are used as antibiotics in medicine and help to create a vaccine. Keeping in mind these applications, the current research provides a mathematical model for bioconvection Sutterby nanofluid flowing past the rotating stretching disk with magnetic field, motile microorganisms, chemical reactions and heat generation. The Brownian movement and thermophoresis diffusions are also considered. The governing equation structures are simplified by suitable transformations. A popular bvp4c solver in MATLAB computational software is employed to achieve numerical results for the non-linear model. The flow evaluation for the effects of several prominent numbers on temperature, velocities, concentration and motile microorganism profiles is executed graphically and numerically. The volumetric concentration of nanomaterial rises for thermophoresis number while shows opposite nature for Prandtl and Lewis parameters. The boosting values of bioconvection Lewis number, Peclet number and bioconvection Rayleigh number decay the motile microorganisms’ concentration.
Stokes phenomenon and gravitational particle production — How to evaluate it in practice
Authors: Hashiba Soichiro , Yamada Yusuke 
Published: May 2021

Abstract
We revisit gravitational particle production from the Stokes phenomenon viewpoint, which helps us make a systematic way to understand asymptotic behavior of mode functions in time-dependent background. One of our purposes of this work is to make the method more practical for evaluation of non-perturbative particle production rate. In particular, with several examples of time-dependent backgrounds, we introduce some approximation methods that make the analysis more practical. Specifically, we consider particle production in simple expanding backgrounds, preheating after R2 inflation, and a transition model with smoothly changing mass. As we find several technical issues in analyzing the Stokes phenomenon of each example, we discuss how to simplify the problems while showing the accuracy of analytic estimation under the approximations we make.
Relativistic stars in 4D Einstein-Gauss-Bonnet gravity
Authors: Doneva Daniela D. , Yazadjiev Stoytcho S. 
Published: May 2021

Abstract
In the present paper we investigate the structure of relativistic stars in 4D Einstein-Gauss-Bonnet gravity. The mass-radius relations are obtained for realistic hadronic and for strange quark star equations of state, and for a wide range of the Gauss-Bonnet coupling parameter α. Even though the deviations from general relativity for nonzero values of α can be large enough, they are still comparable with the variations due to different modern realistic equations of state if we restrict ourselves to moderate values of α. That is why the current observations of the neutron star masses and radii alone can not impose stringent constraints on the value of the parameter α. Nevertheless some rough constraints on α can be put. The existence of stable stellar mass black holes imposes √(α) ≲ 2.6 km for α > 0 while the requirement that the maximum neutron star mass should be greater than two solar masses gives √(|α|) ≲ 3.9 km for α < 0. We also present an exact solution describing the structure of relativistic stars with uniform energy density in 4D Einstein-Gauss-Bonnet gravity.
Saturation of electron emission with increasing ultrarelativistic intensity of the Gaussian laser pulse
Authors: Borovskiy A V , Galkin A L 
Published: May 2021

Abstract
Symmetric electron trajectories in the field of a Gaussian laser pulse are calculated as trajectories with compensation of the dynamic shock at the initial instant of motion. It is shown that the symmetric trajectories have an extremal property, namely, at a fixed peak intensity of the pulse, the time dependence of the electron emission intensity from a symmetric trajectory has the maximum width and amplitude compared to all other trajectories. Formation of paired peaks of electron emission intensity with changing laser pulse peak intensity is analyzed. It is found that the electron emission energy saturates with increasing peak intensity of the laser field in the ultrarelativistic region.
Input–output slope curve estimation in neural stimulation based on optimal sampling principles
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Authors: Mohammad Mahdi Alavi Seyed , Goetz Stefan M , Saif Mehrdad 
Published: May 2021

Abstract
This paper discusses some of the practical limitations and issues, which exist for the input–output (IO) slope curve estimation (SCE) in neural, brain and spinal, stimulation techniques. The drawbacks of the SCE techniques by using existing uniform sampling and Fisher-information-based optimal IO curve estimation (FO-IOCE) methods are elaborated. A novel IO SCE technique is proposed with a modified sampling strategy and stopping rule which improve the SCE performance compared to these methods. The effectiveness of the proposed IO SCE is tested on 1000 simulation runs in transcranial magnetic stimulation (TMS), with a realistic model of motor evoked potentials. The results show that the proposed IO SCE method successfully satisfies the stopping rule, before reaching the maximum number of TMS pulses in 79.5% of runs, while the estimation based on the uniform sampling technique never converges and satisfies the stopping rule. At the time of successful termination, the proposed IO SCE method decreases the 95th percentile (mean value in the parentheses) of the absolute relative estimation errors (AREs) of the slope curve parameters up to 7.45% (2.2%), with only 18 additional pulses on average compared to that of the FO-IOCE technique. It also decreases the 95th percentile (mean value in the parentheses) of the AREs of the IO slope curve parameters up to 59.33% (16.71%), compared to that of the uniform sampling method. The proposed IO SCE also identifies the peak slope with higher accuracy, with the 95th percentile (mean value in the parentheses) of AREs reduced by up to 9.96% (2.01%) compared to that of the FO-IOCE method, and by up to 46.29% (13.13%) compared to that of the uniform sampling method.
Development and performance of high voltage electrodes for the LZ experiment
Authors: Stifter Kelly 
Published: May 2021

Abstract
LZ is a next-generation dark matter search experiment designed to significantly extend our sensitivity to WIMP dark matter candidates. At the core of the LZ detector is a dual-phase xenon time projection chamber (TPC) with a 7-ton active mass. To observe signals from low-energy nuclear recoils, including WIMP-xenon scatters, four custom-woven wire-mesh grids of 1.5m diameter establish strong electric fields in the TPC to drift ionization electrons across the volume and extract them from the liquid surface. As a result of the high electric fields, dielectric breakdown between high voltage surfaces and spurious electron emission from regions of high surface fields are major concerns. To mitigate these risks, an R&D program exploring design geometry in high field regions, cleanliness procedures, and surface treatments has been carried out using a comprehensive suite of three mid-scale dual- and single-phase xenon detectors. These proceedings will summarize the design and construction of the LZ grids, and several aspects of the high voltage performance seen in the testing program.
Dark Matter Searches with the COSINE-100 Experiment
Authors: Govinda Adhikari 
Published: May 2021

Abstract
COSINE-100 is a direct dark matter detection experiment that aims to test DAMA/LIBRA’s claim of dark matter discovery using 106 kg of low-background NaI(Tl) detectors submerged in a 2-tonne liquid scintillator veto. The physics run of the experiment began in September 2016, and a 3.5 count/kg/day/keV background level within the 2-6 keV region of interest has been achieved. Several physics analyses, including WIMP searches and an annual modulation search, have been performed using a 2 keV energy threshold. Recently, this threshold has been lowered to 1 keV. In this talk, we describe the method used to lower the threshold to 1 keV and recent results with this lowered threshold.
DARWIN: direct dark matter search with the ultimate detector
Authors: Macolino Carla 
Published: May 2021

Abstract
DARk matter WImp search with liquid xenoN (DARWIN) is a future experiment for the direct detection of dark matter based on a multi-ton liquid xenon time projection chamber. The main goal of DARWIN is to reach an unprecedented sensitivity to WIMP (Weakly Interacting Massive Particle)-nuclear recoil cross sections for a large WIMP mass range, down to the level where the irreducible background from neutrino interactions with the target is dominant. This ultra-low background experiment will also have competitive sensitivity to test other dark matter hypotheses such as dark photons and superWIMPs and to detect other rare events like solar neutrinos, neutrinoless double-beta decay of 136Xe, solar axions and neutrinos from galactic supernovae. In this paper we present the design of the DARWIN detector and the estimated WIMP sensitivity based on the expected backgrounds. Other rare event searches are also discussed.
The readout system based on the ultra-fast waveform sampler DRS4 for the Large-Sized Telescope of the Cherenkov Telescope Array
Authors: Nozaki S , Blanch O , Delgado C , Gliwny P , Hadasch D , Inome Y , Katagiri H , Kubo H , Kobayashi Y , Mazin D , Moralejo A , Nogami Y , Paoletti R , Saito T , Sakurai S , Sitarek J , Takahashi M , Teshima M , Yamamoto T 
Published: May 2021

Abstract
The Cherenkov Telescope Array (CTA) is the next-generation ground-based very-high-energy gamma-ray observatory. By using three types of telescopes CTA can cover a wide energy range (20 GeV–300 TeV) with an order of magnitude higher sensitivity than the current telescopes. The Large-Sized Telescope (LST) is designed to detect 20 GeV–1 TeV gamma rays thanks to the large light collection area, sensitive photosensors, a fast trigger system, and readout electronics. The camera readout system must have a high signal-to-noise ratio and a linear signal sampling with a large dynamic range in order to efficiently detect dim and low-energy atmospheric showers. To meet this requirement we use the Domino Ring Sampler version 4 (DRS4), which also enables ultra-fast sampling with low power consumption. Some of the intrinsic characteristics of DRS4 chips require software corrections. These procedures lower the effect of non-Gaussian noise contribution and improve the timing resolution of the system. In this contribution we discuss the calibration algorithms and the resulting performance.
Signal Readout Electronics for LEGEND-200
Authors: Willers Michael 
Published: May 2021

Abstract
LEGEND (Large Enriched Germanium Experiment for Neutrinoless Double-Beta Decay) is a ton-scale experimental program to search for neutrinoless double beta (0vββ) decay using high-purity germanium detectors enriched in the isotope 76Ge. An observation of 0vββ decay would unequivocally prove the existence of lepton number violation and provide insight into the nature of neutrino masses.
On-site construction for the first 200-kg phase (LEGEND-200) of the experiment will start at the Gran Sasso underground laboratory (Laboratory Nazionali del Gran Sasso, Italy) in mid-2020. In order to achieve a sensitivity of 1027 years on the 0vββ half-life, ultra-clean low-noise signal readout electronics are essential as they impact both the background budget of the experiment and the efficiency of background rejection. In this contribution, the current status of the signal readout electronics for LEGEND-200 is presented.
Performance of the low threshold Optimum Trigger on CUORE data
Authors: Branca Antonio 
Published: May 2021

Abstract
The Optimum Trigger (OT) is based on a threshold algorithm applied on waveforms filtered by exploiting the matched filter technique. The OT trigger thresholds improve by 60 – 90% with respect to the thresholds obtained with the standard trigger, ranging between ~ 20 and 100 keV. Low trigger thresholds open the way to Dark Matter searches and to improvements in the neutrinoless double beta decay analysis. Nevertheless, running the OT on CUORE data is demanding from the computational resources point of view. For this reason, the algorithm has been revised and adapted to cope with CUORE data. The work done to implement OT in CUORE and its performances will be discussed.
Simulation study of cosmic-ray muon backgrounds for KamLAND-Zen experiment
Authors: Ieki Sei 
Published: May 2021

Abstract
Neutrino is a major candidate of Majorana particle and the neutrinoless double beta (0v2β) decay is the key physics to prove it. In 2019, KamLAND-Zen experiment have started data taking to search for 0v2β decay with 745 kg of 136Xe as the source. The sensitivity is restricted by the statistics of backgrounds and the most critical ones are induced by spallation reactions of cosmic-ray muons. Physics process and statistics are studied with FLUKA which is widely used simulation tool. The most critical background is the decay of 10C, while FLUKA predicts that heavy isotopes such as 137Xe can be a potential background. We apply delayed coincidence method to quantify those backgrounds and also have been developing new tools focused on space and charge features, pulse shape discrimination and particle identification.
High-energy particle physics with IceCube
Authors: Yuan Tianlu 
Published: May 2021

Abstract
While the Standard Model has experienced great predictive success, the neutrino sector still holds opportunities for surprises. Numerous ongoing and planned experiments exist to probe neutrino properties at low energies. The IceCube Neutrino Observatory, comprised of over 5000 photomultiplier tubes (PMTs) situated in a cubic-kilometer of ice at the geographic South Pole, lies in a unique position to measure neutrinos at energies of a TeV and higher. In these proceedings, I discuss several exciting particle physics measurements using IceCube data and probes of physics beyond the Standard Model.
First results of KamLAND-Zen 800
Authors: Gando Yoshihito 
Published: May 2021

Abstract
KamLAND-Zen is a neutrinoless double beta decay (0vββ) search experiment using xenon 136 and ultra-low background environment of KamLAND (Kamioka Liquid scintillator Anti-Neutrino Detector). KamLAND-Zen collaboration has prepared the KamLAND-Zen 800 project with almost 750 kg of xenon and cleaner container for xenon loaded liquid scintillator. The container production was started in May 2017 and KamLAND-Zen 800 data acquisition was started in January 2019. In this paper, we will describe the KamLAND-Zen 800 project and report on the detector condition, data quality, the first analysis results, and the prospects.
Inner balloon production for KamLAND-Zen 800
Authors: Gando A , Gando Y , Hachiya T , Hayashida S , Hosokawa K , Ikeda H , Obara S , Ozaki H , Ueshima K , Watanabe H 
Published: May 2021

Abstract
KamLAND-Zen searches for neutrinoless double-beta decay with 136Xe loaded liquid scintillator (LS). The LS container, a 25-μm-thick clean nylon inner balloon is a key of the experiment since one of the main backgrounds in the ROI is 214Bi from the inner balloon. In KamLAND-Zen 400 (operated from 2011 to 2015), dust contamination of the inner balloon from the environment limited the sensitivity, although the inner balloon was fabricated at a class-1 super clean room. We improved the production method of the inner balloon for KamLAND-Zen 800 (started DAQ in January, 2019) and successfully reduced the 214Bi background level to one fifteenth as compared to the 2nd phase of KamLAND-Zen 400. The inner balloon film material and requirements, improved fabrication scheme, including establishment of clean environment and dust control, will be described.
Measurements of the reactor antineutrinos with the DANSS experiment
Authors: Alekseev Igor 
Published: May 2021

Abstract
The detector of the reactor antineutrino DANSS is placed on a movable platform below a 3.1 GW industrial reactor of Kalininskaya Nuclear Power Plant. The sensitive volume of the detector is a cubic meter of plastic scintillator assembled from 2500 strips with dual readout by Silicon Photo Multipliers (SiPM) and conventional PMTs (in groups of 50 strips). The detector position provides simultaneously a high neutrino flux and an overburden of about 50 m.w.e., resulting in a high counting rate of inverse beta-decay events and cosmic muons induced background as low as 1.9%. The distance between the reactor core and the detector is changed in a week cycle through three positions 10.7, 11.7 and 12.7 m. This allows systematic-free comparison of the antineutrino spectra measured at different distances by the same detector.
This article presents results of the 2.5 year of data collection with more than 2 million of neutrino events collected.
Basic studies of 3-inch PMT for multi-PMT development
Authors: Inomoto M. , Ishitsuka M. , Kuze M. , Nishimura Y. , Quilain B. 
Published: May 2021

Abstract
Hyper-Kamiokande is the next generation large-scale water Cherenkov detector. In Hyper-Kamiokade and Intermediate Water Cherenkov Detector for its long baseline project with J-PARC neutrino beam, use of multi-PMT, which is made by combination of 3-inch PMTs, is being considered. As part of multi-PMT development, we measured the characteristics of the 3-inch PMT including the temperature dependence of dark noise rate. The dark noise rate is important characteristic for detection of low energy events including neutron tagging. In addition, since PMT is generally susceptible to the magnetic field, we confirmed the photon detection efficiency in the condition where the magnetic field was applied.
First neutrino mass measurement with the KATRIN experiment
Authors: Schlüter Lisa , Lasserre Thierry 
Published: May 2021

Abstract
The KATRIN (Karlsruhe Tritium Neutrino) experiment is designed to determine the effective mass of the electron anti-neutrino with an unprecedented sensitivity of 0.2 eV/c2 (90% C.L.) in a direct and model-independent way. Tritium β-decay electrons, emitted in a high-luminosity molecular source, are analyzed with a MAC-E filter. The effective electron anti-neutrino mass squared is inferred from a fit to the integral spectrum in an energy window close the tritium endpoint. In this work, we report on the analysis of the first four-week science run of KATRIN in spring 2019. Considering statistical and systematic uncertainties, we find a central value of the effective electron anti-neutrino mass of

m
v
2

=
(
−

1.0

−
1.0

+
0.9

)

eV

2

. Following the method of Lokhov and Tkachov, we derive an upper limit of 1.1 eV at 90% C.L. on the absolute neutrino mass scale.