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1
Angloher, G., P. Carniti, I. Dafinei, et al. "COSINUS: Cryogenic Calorimeters for the Direct Dark Matter Search with NaI Crystals." Journal of Low Temperature Physics 200, no. 5-6 (2020): 428–36. http://dx.doi.org/10.1007/s10909-020-02464-9.
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Abstract COSINUS (Cryogenic Observatory for SIgnatures seen in Next-generation Underground Searches) is an experiment employing cryogenic calorimeters, dedicated to direct dark matter search in underground laboratories. Its goal is to cross-check the annual modulation signal the DAMA collaboration has been detecting for about 20 years (Bernabei et al. in Nucl Part Phys Proc 303–305:74–79, 2018. 10.1016/j.nuclphysbps.2019.03.015) and which has been ruled out by other experiments in certain dark matter scenarios. COSINUS can provide a model-independent test by the use of the same target material (NaI), with the additional chance of discriminating $$\beta /\gamma$$ β / γ events from nuclear recoils on an event-by-event basis, by the application of a well-established temperature sensor technology developed within the CRESST collaboration. Each module is constituted by two detectors: the light detector, that is a silicon beaker equipped with a transition edge sensor (TES), and the phonon detector, a small cubic NaI crystal interfaced with a carrier of a harder material (e.g. $$\hbox {CdWO}_4$$ CdWO 4 ), also instrumented with a TES. This technology had so far never been applied to NaI crystals because of several well-known obstacles, and COSINUS is the first experiment which succeeded in operating NaI crystals as cryogenic calorimeters. Here, we present the COSINUS project, describe the achievements and the challenges of the COSINUS prototype development and discuss the status and the perspectives of this NaI-based cryogenic frontier.
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Pignard, Olivier. "Strong/nuclear force in the dynamic medium of reference (DMR) theory. Nuclear deflection of light, nuclear time delay of light, and proposed experiment." Physics Essays 34, no. 4 (2021): 517–28. http://dx.doi.org/10.4006/0836-1398-34.4.517.
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The theory of the dynamic medium of reference has already been presented in several articles [Pignard, Phys. Essays 32, 422 (2019); 33, 395 (2020); 34, 61 (2021); 34, 279 (2021)], and in particular in Pignard, Phys. Essays 32, 422 (2019). The article [Pignard, Phys. Essays 34, 279 (2021)] gives an explanation and mathematical developments of the gravitational acceleration from atomic nuclei of a massive body. General relativity considers a massive body, like the Earth or the Sun, globally, macroscopically, simply as an object of mass M (which curves space‐time). However, when one goes into details, this mass M is made up of atoms which are themselves mainly made up of nuclei of nucleons (if we neglect the mass of electrons in comparison of that of the nucleus). Thus, it is mainly the nuclei of a massive body that create the force of gravity! The dynamic medium of reference theory determines the gravitational acceleration microscopically by taking into account all the atomic nuclei that make up a massive body [Pignard, Phys. Essays 32, 422 (2019)]. This creates a strong link between gravity and the nuclear domain. This article goes further with the description of a model of the atomic nucleus. This makes it possible to establish that the strong force or nuclear force, which ensures the cohesion of the nucleus, is due to the strong acceleration of the flux of the medium which is a vector average of the flux of gravitons. This gives an expression of the nuclear force similar to the force of gravity but with a constant K ≈ 1031 m s−2, much higher than the gravitational constant G. This article shows that the functioning, the mechanism of the nucleus, makes it possible to explain the nuclear force and also to find the gravitational acceleration. From there, it is deduced that the photons are deflected by the strong acceleration due to an atom nucleus. They are also slowed down by an atom nucleus which creates a delay in their travel time which we call the nuclear time delay of light. Finally, an experiment is proposed to verify the phenomenon of nuclear deflection of light and the nuclear time delay of light.
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WANG, Y. Z., Q. F. GU, J. M. DONG, and B. B. PENG. "ALPHA DECAY HALF-LIVES OF EXOTIC NUCLEI AROUND SHELL CLOSURES." International Journal of Modern Physics E 20, no. 01 (2011): 127–38. http://dx.doi.org/10.1142/s0218301311017375.
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In the framework of the generalized liquid drop model (GLDM) and improved Royer's formula with a set of new coefficients derived by N. D. Schubert et al. [Eur. Phys. J. A42 (2009) 121], the favored and unfavored α-decay half-lives of exotic nuclei around closed shells Z = 82 and N = 126 are investigated. The calculated results are in good agreement with the experimental data. It is shown that our method can be used to study the α-decay half-lives of exotic nuclei around shell closures successfully and is helpful for future research on superheavy nuclei around the next proton and neutron shell closures. In addition, some α-decay half-lives for the cases where the experimental values are unavailable are predicted. We hope our predicted results are useful for future experiments.
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Galati, Giuliana, Andrey Alexandrov, Behcet Alpat, et al. "Charge identification of fragments with the emulsion spectrometer of the FOOT experiment." Open Physics 19, no. 1 (2021): 383–94. http://dx.doi.org/10.1515/phys-2021-0032.
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Abstract The FOOT (FragmentatiOn Of Target) experiment is an international project designed to carry out the fragmentation cross-sectional measurements relevant for charged particle therapy (CPT), a technique based on the use of charged particle beams for the treatment of deep-seated tumors. The FOOT detector consists of an electronic setup for the identification of Z ≥ 3 Z\ge 3 fragments and an emulsion spectrometer for Z ≤ 3 Z\le 3 fragments. The first data taking was performed in 2019 at the GSI facility (Darmstadt, Germany). In this study, the charge identification of fragments induced by exposing an emulsion detector, embedding a C 2 H 4 {{\rm{C}}}_{2}{{\rm{H}}}_{4} target, to an oxygen ion beam of 200 MeV/n is discussed. The charge identification is based on the controlled fading of nuclear emulsions in order to extend their dynamic range in the ionization response.
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Tierens, W., J. R. Myra, R. Bilato, and L. Colas. "Resonant wave–filament interactions as a loss mechanism for HHFW heating and current drive." Plasma Physics and Controlled Fusion 64, no. 3 (2022): 035001. http://dx.doi.org/10.1088/1361-6587/ac3cfe.
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Abstract Perkins et al (2012 Phys. Rev. Lett. 109 045001) reported unexpected power losses during high harmonic fast wave (HHFW) heating and current drive in the National Spherical Torus Experiment (NSTX). Recently, Tierens et al (2020 Phys. Plasmas 27 010702) proposed that these losses may be attributable to surface waves on field-aligned plasma filaments, which carry power along the filaments, to be lost at the endpoints where the filaments intersect the limiters. In this work, we show that there is indeed a resonant loss mechanism associated with the excitation of these surface waves, and derive an analytic expression for the power lost to surface wave modes at each filament.
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Aleev, A. N., N. S. Amaglobeli, V. P. Balandin та ін. "Erratum: “Associated φΛ0 production in the EXCHARM experiment” [Phys. At. Nucl. 67, 1513 (2004)]". Physics of Atomic Nuclei 67, № 10 (2004): 1930. http://dx.doi.org/10.1134/1.1811201.
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Cho, Won Sang, Ji-Haeng Huh, Ian-Woo Kim, Jihn E. Kim, and Bumseok Kyae. "Erratum to “Constraining WIMP magnetic moment from CDMS II experiment” [Phys. Lett. B 687 (1) (2010) 6]." Physics Letters B 694, no. 4-5 (2011): 496–97. http://dx.doi.org/10.1016/j.physletb.2010.09.048.
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CABELLO, ADÁN. "KOCHEN–SPECKER THEOREM AND EXPERIMENTAL TEST ON HIDDEN VARIABLES." International Journal of Modern Physics A 15, no. 18 (2000): 2813–20. http://dx.doi.org/10.1142/s0217751x00002020.
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A recent proposal to experimentally test quantum mechanics against noncontextual hidden-variable theories [Phys. Rev. Lett.80, 1797 (1998)] is shown to be related with the smallest proof of the Kochen–Specker theorem currently known [Phys. Lett.A212, 183 (1996)]. This proof contains eighteen yes-no questions about a four-dimensional physical system, combined in nine mutually incompatible tests. When these tests are considered as tests about a two-part two-state system, then quantum mechanics and noncontextual hidden variables make the same predictions for eight of them, but make different predictions for the ninth. Therefore, this ninth test would allow us to discriminate between quantum mechanics and noncontextual hidden-variable theories in a (gedanken) single run experiment.
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Milotti, E., S. Bartalucci, S. Bertolucci, et al. "VIP: AN EXPERIMENT TO SEARCH FOR A VIOLATION OF THE PAULI EXCLUSION PRINCIPLE." International Journal of Modern Physics A 22, no. 02n03 (2007): 242–48. http://dx.doi.org/10.1142/s0217751x07035392.
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The Pauli Exclusion Principle is a basic principle of Quantum Mechanics, and its validity has never been seriously challenged. However, given its fundamental standing, it is very important to check it as thoroughly as possible. Here we describe the VIP (VIolation of the Pauli exclusion principle) experiment, an improved version of the Ramberg and Snow experiment (E. Ramberg and G. Snow, Phys. Lett. B238, 438 (1990)); VIP has just completed the installation at the Gran Sasso underground laboratory, and aims to test the Pauli Exclusion Principle for electrons with unprecedented accuracy, down to β2/2 ≈ 10-30 - 10-31. We report preliminary experimental results and briefly discuss some of the implications of a possible violation.
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Shi, Shengyu, Jiale Chen, Xiang Jian, et al. "Illustrating the physics of core tungsten (W) transport in a long-pulse steady-state H-mode discharge on EAST." Nuclear Fusion 62, no. 6 (2022): 066040. http://dx.doi.org/10.1088/1741-4326/ac548b.
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Abstract The behavior of core tungsten (W) in a pure radio-frequency-heated long-pulse steady-state H-mode discharge in the Experimental Advanced Superconducting Tokamak (EAST) with an ITER-like divertor (ILD) is analyzed using experimental diagnostic data and modeled using a combination of drift-kinetic neoclassical and gyro-fluid turbulent software. In the steady state, the experimental core line-averaged W concentration (C W) is about 2 × 10−5, which is evaluated using the intensity of the W unresolved transition array (W-UTA) spectral structure in the region of 45–70 Å (which is composed of W 27+–W 45+ line emissions) through spectroscopy in the extreme ultraviolet region. W produces a peak of the radiated power density profile around a normalized radius of ρ ∼ 0.3. Therefore, W does not centrally accumulate in the experiment. A time slice of the steady-state is modeled, which accounts for both the neoclassical and turbulent transport components of W based on the self-consistent background plasma profiles simulated by TGYRO (Candy et al 2009 Phys. Plasmas 16 060704). It is found that turbulent transport dominates over neoclassical transport for W. In addition, the turbulent diffusion coefficient is large enough to offset the sum of the neoclassical and turbulent pinch (convection) velocities, so that the W density profile for a zero particle flux is not strongly peaked. By combining TGLF (Staebler et al 2017 Nucl. Fusion 57 066046) and NEO (Belli and Candy 2008 Plasma Phys. Control. Fusion 50 095010; 2012 Plasma Phys. Control. Fusion 54 015015) for the W transport coefficient with the impurity transport code STRAHL (Dux 2006 STRAHL User Manual), the experimental C W and the information radiated by W can be reproduced closely. In addition, the effect of toroidal rotation on the W transport is also clarified.
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Biçer, Ahmet, Kaan Manisa, Abdullah Engin Çalık, et al. "Determination of the energy transitions and half-lives of Rubidium nuclei." Open Physics 16, no. 1 (2018): 63–68. http://dx.doi.org/10.1515/phys-2018-0012.
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Abstract The photonuclear reactions, first extensively studied in the 1970’s and performed using the gamma rays obtained via bremsstrahlung, are a standard nuclear physics experiment. In this study, a non-enriched Rubidium sample was irradiated with photons produced by a clinical linear electron accelerator (cLINACs) with energies up to 18 MeV with the aim of activating it through photonuclear reactions. The activated sample was measured with a high purity germanium detector (HPGe) with the aim of measuring the transition energies and half-lives. The spectroscopic analysis performed on the obtained data yielded high quality results for the transition energies with precision matching or surpassing the literature data. For the half-lives the results were consistent with the literature, most notably the half-life of 84mRb decay was determined as 20.28(2) m. The results for both energies and half-lives further show that the clinical linear accelerators can be successfully used as an efficient tool in experimental nuclear research endeavors.
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García-Abenza, Adrián, Ana I. Lozano, Juan C. Oller, et al. "Evaluation of Recommended Cross Sections for the Simulation of Electron Tracks in Water." Atoms 9, no. 4 (2021): 98. http://dx.doi.org/10.3390/atoms9040098.
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The accuracy of the most recent recommended cross sections dataset for electron scattering from gaseous H2O (J. Phys. Chem. Ref. Data 2021, 50, 023103) is probed in a joint experimental and computational study. Simulations of the magnetically confined electron transport through a gas cell containing H2O for different beam energies (3, 10 and 70 eV) and pressures (2.5 to 20.0 mTorr) have been performed by using a specifically designed Monte Carlo code. The simulated results have been compared with the corresponding experimental data as well as with simulations performed with Geant4DNA. The comparison made between the experiment and simulation provides insight into possible improvement of the recommended dataset.
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Abbas, Syed Afsar. "Fusion of halo nucleus 6He on 238U : Evidence for tennis-ball (bubble) structure of the core of the halo (even the giant-halo) nucleus." Modern Physics Letters A 34, no. 27 (2019): 1950221. http://dx.doi.org/10.1142/s0217732319502213.
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In a decade-and-a-half old experiment, Raabe et al. [Nature 431, 823 (2004)], had studied fusion of an incoming beam of halo nucleus 6He with the target nucleus [Formula: see text]. We extract a new interpretation of the experiment, different from the one that has been inferred so far. We show that their experiment is actually able to discriminate between the structures of the target nucleus (behaving as standard nucleus with density distribution described with canonical RMS radius [Formula: see text] with [Formula: see text] fm), and the “core” of the halo nucleus, which surprisingly, does not follow the standard density distribution with the above RMS radius. In fact, the core has the structure of a tennis-ball (bubble)-like nucleus, with a “hole” at the center of the density distribution. This novel interpretation of the fusion experiment provides an unambiguous support to an almost two decades old model [A. Abbas, Mod. Phys. Lett. A 16, 755 (2001)], of the halo nuclei. This Quantum Chromodynamics based model succeeds in identifying all known halo nuclei and makes clear-cut and unique predictions for new and heavier halo nuclei. This model supports the existence of tennis-ball (bubble)-like core, of even the giant-neutron halo nuclei. This should prove beneficial to the experimentalists, to go forward more confidently, in their study of exotic nuclei.
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Pradler, Josef, and Itay Yavin. "Addendum to “On an unverified nuclear decay and its role in the DAMA experiment” [Phys. Lett. B 720 (4–5) (2013) 399–404]." Physics Letters B 723, no. 1-3 (2013): 168–71. http://dx.doi.org/10.1016/j.physletb.2013.04.045.
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Yuan, Hao, and Zhanjun Zhang. "Optimizing the scheme of bidirectional controlled quantum teleportation with a genuine five-qubit entangled state." Modern Physics Letters A 35, no. 36 (2020): 2050301. http://dx.doi.org/10.1142/s0217732320503010.
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A bidirectional controlled quantum teleportation (BCQT) scheme was proposed by Yan Chen [Int. J. Theor. Phys. 53, 1454 (2014)] with a genuine five-qubit entangled state as quantum channel. In the scheme two remote participants have to perform some two-qubit joint operations to accomplish the BCQT task. Such joint operations are nonlocal and usually regarded as serious faults in some sense. To overcome them, in this paper we put forward an optimized version. Our scheme has the distinct advantages of degrading the necessary-operation complexity (i.e., both intensity and difficulty) and consuming fewer classical resources as well as owing higher intrinsic efficiency in contrast to Chen’s. Besides, it is feasible in experiment and applicable in the intending quantum network.
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Aharonian, F., Q. An, Axikegu, et al. "Corrigendum to “Performance test of the electromagnetic particle detectors for the LHAASO experiment” [Nucl. Instrum. Methods Phys. Res. A 1001 (2021) 165193]." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 1022 (January 2022): 165986. http://dx.doi.org/10.1016/j.nima.2021.165986.
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Natochii, A., T. E. Browder, L. Cao, et al. "Corrigendum to “Measured and projected beam backgrounds in the Belle II experiment at the SuperKEKB collider” [Nucl. Instrum. Methods Phys. Res. A 1055 (2023) 168550]." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 1060 (March 2024): 169037. http://dx.doi.org/10.1016/j.nima.2023.169037.
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Shanahan, B., C. Killer, G. Pechstein, S. A. Henneberg, G. Fuchert, and O. Grulke. "Estimating the error in filament propagation measurement using a synthetic probe." Plasma Physics and Controlled Fusion 63, no. 12 (2021): 125018. http://dx.doi.org/10.1088/1361-6587/ac2ff7.
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Abstract Electric probe arrangements are a standard tool for investigating plasma filaments in the scrape-off layer of magnetic fusion experiments. In the Wendelstein 7-X stellarator, recent work has characterized plasma filaments using reciprocating electric probes and provided a comparison of filament scaling to simulated filaments, showing remarkable agreement (Killer et al 2020 Plasma Phys. Control. Fusion 62 085003). Here, such simulations are further employed to assess uncertainties inherent to probe measurements by introducing a synthetic probe diagnostic into the simulation. It is determined that filament diameters, and to a smaller degree radial filament velocities, are inherently underestimated in experiment when a filament is not centered on the probe tip. Filament velocity measurements are also sensitive to the alignment of the probes relative to the poloidal direction and the distance between pins. Floating potential pins which are spaced too far apart will underestimate filament velocity, whereas pins which are closely-spaced can overestimate the filament velocity. The sensitivity of the floating potential measurements—from which radial velocity is extracted—to temperature fluctuations is discussed. These investigations apply to measurements of filaments by electric probes in tokamaks as well and may serve as guidance for interpreting probe data and designing probe arrays.
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Ullah, S., Y. Ali, M. Ajaz, U. Tabassam та Q. Ali. "π±, K±, protons and antiprotons production in proton–carbon interactions at 31 GeV/c using hadron production models". International Journal of Modern Physics A 33, № 17 (2018): 1850108. http://dx.doi.org/10.1142/s0217751x18501087.
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Projects proposed for the long baseline neutrino and cosmic rays’ experiments require high precision hadron production measurements, using proton beam on different targets, to achieve their physics goals. The predictions of neutrino beam depend on the modeling of protons interacting within the targets. Thus, different hadronic models are being used for this purpose with different precisions, which depend on the projectile protons energy and material of the target used. The comparison of different hadron production models predictions, in proton–carbon interactions at 31 GeV/c, is reported in this paper. Double differential yield of [Formula: see text], [Formula: see text] mesons, protons and antiprotons in several polar angle ranges is presented as a function of laboratory momentum. EPOS1.99, EPOS-LHC and QGSJETII-04 models are used to perform simulations. The results of the simulated data are compared with hadron production measurements in proton–carbon interactions at 31 GeV/c performed by the NA61/SHINE experiment at the SPS CERN [Eur. Phys. J. C 76, 84 (2016)]. None of the models completely describes all the distributions. In most of the cases, EPOS1.99 describes the experimental data very well. EPOS-LHC results are also similar in some cases, but QGSJETII-04 predictions failed to reproduce the experimental data.
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Garofalo, A. M., S. Ding, W. M. Solomon, et al. "Deconvolving the roles of E × B shear and pedestal structure in the energy confinement quality of super H-mode experiments." Nuclear Fusion 62, no. 5 (2022): 056008. http://dx.doi.org/10.1088/1741-4326/ac4d63.
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Abstract Analysis of ‘super H-mode’ experiments on DIII-D has put forward that high plasma toroidal rotation, not high pedestal, plays the essential role in achieving energy confinement quality H 98y2 ≫ 1 (Ding et al 2020 Nucl. Fusion 60 034001). Recently, super H-mode experiments with variable input torque have confirmed that high rotation shear discharges have very high levels of H 98y2 (>1.5), independent of the pedestal height, and that high pedestal discharges with low rotation shear have levels of H 98y2 only slightly above 1 (⩽1.2). Although some increase in stored energy with higher pedestal occurs, the energy confinement quality mainly depends on the toroidal rotation shear, which varies according to different levels of injected neutral beam torque per particle. Quasi-linear gyrofluid modeling achieves a good match of the experiment when including the E × B shear; without including plasma rotation, the modeling predicts a confinement quality consistent with the empirical observation of H 98y2 ∼ 1.2 at low rotation. Nonlinear gyrokinetic transport modeling shows that the effect of E × B turbulence stabilization is far larger than other mechanisms, such as the so-called hot-ion stabilization (T i/T e) effect. Consistent with these experimental and modeling results are previous simulations of the ITER baseline scenario using a super H-mode pedestal solution (Solomon et al 2016 Phys. Plasmas 23 056105), which showed the potential to exceed the Q = 10 target if the pedestal density could be increased above the Greenwald limit. A close look at these simulations reveals that the predicted energy confinement quality is below 1 even at the highest pedestal pressure. The improvement in Q at higher pedestal density is due to the improved fusion power generation at the higher core density associated with higher pedestal density, not to an improved energy confinement quality.
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Devi, Maibam Ricky, та Kalpana Bora. "Exploring the feasibility of the charged lepton flavor violating decay μ → e + γ in inverse and linear seesaw mechanisms with A4 flavor symmetry". Modern Physics Letters A 37, № 31 (2022). http://dx.doi.org/10.1142/s0217732322502066.
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One of the possible ways to explain the observed flavor structure of fundamental particles is to include flavor symmetries in the theories. In this work, we investigate the rare charged lepton flavor violating (cLFV) decay process [Formula: see text] in two of the low-scale ([Formula: see text][Formula: see text]TeV) seesaw models: (i) the Inverse seesaw (ISS) and (ii) Linear seesaw (LSS) models within the framework of [Formula: see text] flavor symmetry. Apart from the [Formula: see text] flavor symmetry, some other symmetries like [Formula: see text], [Formula: see text] and [Formula: see text] are included to construct the Lagrangian. We use results from our previous work [M. R. Devi and K. Bora, A comparative study of type-II, inverse and linear seesaw mechanisms with [Formula: see text] flavor symmetry, presented at DAE HEP Symp., 2020, Jatni, Odisha; M. R. Devi and K. Bora, Mod. Phys. Lett. A 37, 2250073] where we computed unknown neutrino oscillation parameters within [Formula: see text] limits of their global best fit values, and apply those results to compute the branching ratio (BR) of the muon decay for both the seesaw models. Next we compare our results with the current experimental bounds and sensitivity limits of BR[Formula: see text] as projected by various experiments, and present a comparative analysis that which of the two models is more likely to be tested by which current/future experiment. This is done for various values of currently allowed non-unitarity parameter. This comparative study will help us to pinpoint that which of the low-scale seesaw models and triplet flavon VEV alignments will be more viable and favorable for testing under a common flavor symmetry ([Formula: see text] here), and hence can help discriminate between the two models.
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Arcones, Almudena, and Friedrich-Karl Thielemann. "Origin of the elements." Astronomy and Astrophysics Review 31, no. 1 (2022). http://dx.doi.org/10.1007/s00159-022-00146-x.
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AbstractWhat is the origin of the oxygen we breathe, the hydrogen and oxygen (in form of water H2O) in rivers and oceans, the carbon in all organic compounds, the silicon in electronic hardware, the calcium in our bones, the iron in steel, silver and gold in jewels, the rare earths utilized, e.g. in magnets or lasers, lead or lithium in batteries, and also of naturally occurring uranium and plutonium? The answer lies in the skies. Astrophysical environments from the Big Bang to stars and stellar explosions are the cauldrons where all these elements are made. The papers by Burbidge (Rev Mod Phys 29:547–650, 1957) and Cameron (Publ Astron Soc Pac 69:201, 1957), as well as precursors by Bethe, von Weizsäcker, Hoyle, Gamow, and Suess and Urey provided a very basic understanding of the nucleosynthesis processes responsible for their production, combined with nuclear physics input and required environment conditions such as temperature, density and the overall neutron/proton ratio in seed material. Since then a steady stream of nuclear experiments and nuclear structure theory, astrophysical models of the early universe as well as stars and stellar explosions in single and binary stellar systems has led to a deeper understanding. This involved improvements in stellar models, the composition of stellar wind ejecta, the mechanism of core-collapse supernovae as final fate of massive stars, and the transition (as a function of initial stellar mass) from core-collapse supernovae to hypernovae and long duration gamma-ray bursts (accompanied by the formation of a black hole) in case of single star progenitors. Binary stellar systems give rise to nova explosions, X-ray bursts, type Ia supernovae, neutron star, and neutron star–black hole mergers. All of these events (possibly with the exception of X-ray bursts) eject material with an abundance composition unique to the specific event and lead over time to the evolution of elemental (and isotopic) abundances in the galactic gas and their imprint on the next generation of stars. In the present review, we want to give a modern overview of the nucleosynthesis processes involved, their astrophysical sites, and their impact on the evolution of galaxies.
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Liu, Yueqiang, SeongMoo Yang, Jisung Kang, et al. "MARS-F/K modeling of plasma response and fast ion losses due to RMP in KSTAR." Nuclear Fusion, March 4, 2024. http://dx.doi.org/10.1088/1741-4326/ad2fe8.
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Abstract The toroidal single-fluid magnetohydrodynamic (MHD) code MARS-F (Liu Y.Q. et al 2000 Phys. Plasmas 7 3681) and the MHD-kinetic hybrid code MARS-K (Liu Y.Q. et al 2008 Phys. Plasmas 15 112503) are utilized to study the plasma response to the n=1 (n is the toroidal mode number) resonant magnetic perturbation (RMP), applied to suppress the type-I edge localized mode (ELM) in a KSTAR discharge. Both the resistive-rotating and ideal-static plasma models identify strong screening of the resonant radial field harmonics of the applied RMP due to the plasma response, and predict a strong edge-peeling response of the plasma which is consistent with the optimal ELM control coil current configuration adopted in experiment. The RMP-induced radial displacement of the plasma, computed by the resistive-rotating plasma model, agrees reasonably well with that reconstructed from the measured data in the plasma core. Taking into account the drift kinetic response of fast ions, MARS-K hybrid modeling also finds quantitative agreement of the plasma core fluid pressure perturbation with experiment. Based on the MARS-F computed plasma response, a guiding-center orbit-tracing simulation finds about 0.3% of fast ion losses due the n=1 RMP in the KSTAR ELM control experiment considered. Most losses are associated with counter-current fast ions located near the plasma edge.
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Schonfeld, Jonathan F. "Does the Mott problem extend to Geiger counters?" Open Physics 21, no. 1 (2023). http://dx.doi.org/10.1515/phys-2023-0125.
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Abstract The Mott problem is a simpler version of the quantum measurement problem that asks: Is there a microscopic physical mechanism – based (explicitly or implicitly) only on Schroedinger’s equation – that explains why a single alpha particle emitted in a single spherically symmetric s-wave nuclear decay produces a manifestly nonspherically symmetric single track in a cloud chamber? I attempt here to generalize earlier work that formulated such a mechanism. The key ingredient there was identification of sites at which the cross section for ionization by a passing charged particle is near singular at ionization threshold. This near singularity arose from a Penning-like process involving molecular polarization in subcritical vapor clusters. Here, I argue that the same Mott problem question should be asked about Geiger counters. I then define a simple experiment to determine if ionization physics similar to the cloud chamber case takes place in the mica window of a Geiger counter and explains the collimation of wavefunctions that are spherically symmetric outside the counter into linear ion tracks inside. The experiment measures the count rate from a radioactive point source as a function of source-window separation. I have performed a proof of concept of this experiment; results are reported here and support the near-singular-ionization picture. These results are significant in their own right, and they may shed light on physical mechanisms underlying instances of the full quantum measurement problem. I illustrate this for the Stern–Gerlach experiment and a particular realization of superconducting qubits. I conclude by detailing further work required to flesh out these results more rigorously.
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Zou, Qian, Jun Cheng, Yuhong Xu, et al. "Effect of impurity ions on the coupling between zonal flows and local turbulent transport in HL-2A plasmas." Nuclear Fusion, April 8, 2022. http://dx.doi.org/10.1088/1741-4326/ac65a0.
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Abstract The effect of impurity ions on the coupling between geodesic acoustic mode (GAM) zonal flows and local turbulent transport has been studied using a Langmuir probe array in HL-2A ohmically-heated deuterium plasmas. The experimental results illustrate that both frequency and amplitude level of the GAM zonal flow significantly reduce with the increase of carbon ions concentration, which is qualitatively consistent with the theoretical prediction [B. Xie et al. Plasma Phys. Controlled Fusion 60 025015 (2018)], meanwhile the less energy is transferred from turbulence to GAM zonal flows due to the reduction in tilting and stretching of turbulent vortex. Consequently, the impurity ions stir the enhancement of turbulence and turbulent transport owing to the reduced GAM zonal flow as demonstrated in the experiment. These experimental results presented here therefore reveal the dual roles played by impurity ions on the dynamics of GAM zonal flows.
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Pacetti, Simone, and Egle Tomasi-Gustafsson. "The origin of the proton radius puzzle." European Physical Journal A 57, no. 2 (2021). http://dx.doi.org/10.1140/epja/s10050-021-00398-8.
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AbstractThe dimension of the proton, the basic building block of matter, is still object of controversy. The most precise electron-proton scattering data at low transferred momenta are re-analyzed and the extraction of the proton radius is discussed. A recent experiment from the JLAB-CLAS collaboration gives a small value for the radius (The symbol $$R_E^\alpha $$ R E α stands for the root-mean-square charge radius of the proton $$\sqrt{\langle r_E^2\rangle }$$ ⟨ r E 2 ⟩ , obtained by the experimental or theoretical Collaboration $$\alpha $$ α .) $$R_E^\mathrm{CLAS}= (0.831\pm 0.007_\mathrm{stat}\pm 0.012_\mathrm{syst})$$ R E CLAS = ( 0.831 ± 0 . 007 stat ± 0 . 012 syst ) fm (Xiong et al. in Nature 575:147, 2019), in contrast with previous electron scattering experiments, in particular with the MAINZ experiment (Bernauer et al. (A1 Collaboration), Phys. Rev. C 90:015206, 2014) that concluded $$R_E^\mathrm{MAINZ}= (0.879\pm 0.005_\mathrm{stat}\pm 0.004_\mathrm{syst}\pm 0.002_\mathrm{model}\pm 0.004_\mathrm{group})$$ R E MAINZ = ( 0.879 ± 0 . 005 stat ± 0 . 004 syst ± 0 . 002 model ± 0 . 004 group ) fm. The experimental results are re-analyzed in terms of different fits of the cross section and of its discrete derivative with analyticity constraints. The uncertainty on the derivative is two orders of magnitude larger than the error on the measured observable, i.e., the cross section. The systematic error associated with the radius is evaluated taking into account the uncertainties from different sources, as the extrapolation to the static point, the choice of the class of fitting functions, and the range of the data sample.
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Savelyev, I. M., M. Y. Kaygorodov, Y. S. Kozhedub, I. I. Tupitsyn, and V. M. Shabaev. "Calculations of the Binding-energy Differences for Highly-charged Ho and Dy Ions." JETP Letters, July 17, 2023. http://dx.doi.org/10.1134/s0021364023601975.
Full textAbstract:
The binding-energy differences for 163Hoq+ and 163Dyq+ ions with ionization degrees q = 38, 39, and 40 are calculated. The calculations are performed using the large-scale relativistic configuration-interaction and relativistic coupled-clusters methods. The contributions from quantum-electrodynamics, nuclear-recoil, and frequency-dependent Breit-interaction effects are taken into account. The final uncertainty does not exceed 1 eV. Combining the obtained results with the binding-energy difference for neutral atoms calculated in [I. M. Savelyev, M. Y. Kaygorodov, Y. S. Kozhedub, I. I. Tupitsyn, and V.M. Shabaev, Phys. Rev. A 105, 012806 (2022)], we get the secondary differences of the ion-atom binding energies. These values can be used to evaluate the amount of energy released in the electron capture process in 163Ho atom (the Q value), provided mass differences of highly charged ions 163Hoq+ and 163Dyq+ is known from experiment. The Q value is required by experiments on the determination of the absolute scale of the electron neutrino mass by studying the beta-decay process.
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Dutta, Bhaskar, Doojin Kim, Shu Liao, et al. "Searching for dark matter signals in timing spectra at neutrino experiments." Journal of High Energy Physics 2022, no. 1 (2022). http://dx.doi.org/10.1007/jhep01(2022)144.
Full textAbstract:
Abstract The sensitivity to dark matter signals at neutrino experiments is fundamentally challenged by the neutrino rates, as they leave similar signatures in their detectors. As a way to improve the signal sensitivity, we investigate a dark matter search strategy which utilizes the timing and energy spectra to discriminate dark matter from neutrino signals at low-energy, pulsed-beam neutrino experiments. This strategy was proposed in our companion paper Phys. Rev. Lett.124 (2020) 121802 [1], which we apply to potential searches at COHERENT, JSNS2, and CCM. These experiments are not only sources of neutrinos but also high intensity sources of photons. The dark matter candidate of interest comes from the relatively prompt decay of a dark sector gauge boson which may replace a Standard-Model photon, so the delayed neutrino events can be suppressed by keeping prompt events only. Furthermore, prompt neutrino events can be rejected by a cut in recoil energy spectra, as their incoming energy is relatively small and bounded from above while dark matter may deposit a sizable energy beyond it. We apply the search strategy of imposing a combination of energy and timing cuts to the existing CsI and LAr data of the COHERENT experiment as concrete examples, and report a mild excess beyond known backgrounds. We then investigate the expected sensitivity reaches to dark matter signals in our benchmark experiments.
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Ye, Cheng, Youwen Sun, Hui-Hui Wang, et al. "The effect of plasma toroidal rotation on n=1 resonant magnetic perturbation field penetration under low neutral beam injection torque in EAST." Nuclear Fusion, November 3, 2023. http://dx.doi.org/10.1088/1741-4326/ad0982.
Full textAbstract:
Abstract An experiment was conducted to study the mode penetration of n=1 resonant magnetic perturbation (RMP) in EAST under low neutral beam injection torque in the co-current direction (Co-NBI). The experimental results indicated that the threshold current I_(RMP,th) for field penetration decreases with higher input torque T_NBI. Furthermore, it was observed that the plasma mode frequency |f_MHD | at counter-current direction is greatly reduced when the plasma toroidal rotation frequency f_ϕ increases. The theoretical scaling of mode frequency (I_(RMP,th)∝|f_MHD |^0.70) predicted by the field penetration theory is in good agreement with the experimental observation (I_(RMP,th)∝|f_MHD |^0.53). The role of |f_MHD | and f_ϕ on the mode onset threshold was separately investigated using the full toroidal geometry initial value code MARS-Q [Liu et al, 2013 Phys. Plasmas 20 042503]. The numerical scaling based on experimental mode frequency is consistent with the experimental and theoretical ones. Numerical results suggest that evaluating the total mode frequency |f_MHD | is crucial in field penetration analysis, contrary to toroidal rotation frequency f_ϕ. With the increase of T_NBI, the decreasing |f_MHD | leads to a reduction in the field penetration threshold. It suggests that more attention should be paid to error field tolerance in low Co-NBI torque scenarios, where electron diamagnetic frequency may be canceled out by NBI-driven toroidal plasma rotation.
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Zhang, Neng, Yueqiang Liu, Deliang Yu, et al. "Toroidal modeling of plasma flow damping and density pump-out by RMP during ELM mitigation in HL-2A." Nuclear Fusion, June 19, 2023. http://dx.doi.org/10.1088/1741-4326/acdf71.
Full textAbstract:
Abstract Reduction of both the plasma density and toroidal flow speed, due to application of the predominantly n=1 (n is the toroidal mode number) resonant magnetic perturbation (RMP) for controlling the edge localized mode in the HL-2A tokamak, is numerically investigated utilizing the quasi-linear initial-value code MARS-Q (Liu et al 2013 Phys. Plasmas 20 042503). Simulation results reveal that the neoclassical toroidal viscosity (NTV) due to 3D fields plays the key role in modifying the plasma momentum and particle transport in the HL-2A discharge. By comparing the modeling results with the measured density pump-out in the experiment, the electron NTV particle flux model, in combination with the free-boundary condition for the axisymmetric change of the density at the plasma edge, is found to yield the best agreement in terms of both the pump-out level and the overall time scale. Further sensitivity studies show that the simulated density pump-out level is reasonably robust against variations in the model assumptions, including the particle diffusion model and the non-ambipolar versus ambipolar NTV particle flux. The latter however affects the time scale for reaching the steady state solution. Finally, it is found that the plasma edge-peeling response, the NTV torque, as well as the plasma momentum and particle transport, all are sensitive to the toroidal phase difference between the upper and lower rows of the RMP coil currents in HL-2A, with the 30 degrees coil phasing producing the minimal side effects on the plasma.
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Rodrigues, M. R. D., A. Bonasera, M. Scisciò, et al. "Radioisotope production using lasers: From basic science to applications." Matter and Radiation at Extremes 9, no. 3 (2024). http://dx.doi.org/10.1063/5.0196909.
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The discovery of chirped pulse amplification has led to great improvements in laser technology, enabling energetic laser beams to be compressed to pulse durations of tens of femtoseconds and focused to a few micrometers. Protons with energies of tens of MeV can be accelerated using, for instance, target normal sheath acceleration and focused on secondary targets. Under such conditions, nuclear reactions can occur, with the production of radioisotopes suitable for medical application. The use of high-repetition lasers to produce such isotopes is competitive with conventional methods mostly based on accelerators. In this paper, we study the production of 67Cu, 63Zn, 18F, and 11C, which are currently used in positron emission tomography and other applications. At the same time, we study the reactions 10B(p,α)7Be and 70Zn(p,4n)67Ga to put further constraints on the proton distributions at different angles, as well as the reaction 11B(p,α)8Be relevant for energy production. The experiment was performed at the 1 PW laser facility at Vega III in Salamanca, Spain. Angular distributions of radioisotopes in the forward (with respect to the laser direction) and backward directions were measured using a high purity germanium detector. Our results are in reasonable agreement with numerical estimates obtained following the approach of Kimura and Bonasera [Nucl. Instrum. Methods Phys. Res., Sect. A 637, 164–170 (2011)].
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Di Siena, Alessandro, Roberto Bilato, Tobias Görler, et al. "Core transport barriers induced by fast ions in global gyrokinetic GENE simulations." Plasma Physics and Controlled Fusion, March 30, 2022. http://dx.doi.org/10.1088/1361-6587/ac6276.
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Abstract A novel type of internal transport barrier (ITB) called F-ATB (fast ion-induced anomalous transport barrier) has been recently observed in state-of-the-art global gyrokinetic simulations on a properly optimized ASDEX Upgrade experiment and presented in A. Di Siena et al. Phys. Rev. Lett. {\bf 127} 025002 (2021). Unlike the transport barriers previously reported in the literature, the trigger mechanism for the F-ATB has been shown to be a wave-particle resonant interaction between supra-thermal particles - generated via ion cyclotron resonance heating (ICRH) - and ion scale plasma turbulence. This resonant mechanism strongly depends on the particular shape of the fast ion temperature and density profiles. Therefore, to further improve our theoretical understanding of this transport barrier, we present results exploring the parameter space and physical conditions for the F-ATB generation by performing a systematic study with global GENE simulations. Particular emphasis is given to the transport barrier width and its localization by scanning over different energetic particle temperature profiles. The latter are varied in amplitude, half-width, and radial localization of an ad-hoc Gaussian-like energetic particle logarithmic temperature gradient profile. For the reference parameters at hand, a threshold in the ratio between the fast ion and electron temperature and the amplitude of the fast ion logarithmic temperature gradient is identified to trigger the transport barrier effectively. The role of $q = 1$ rational surface to the transport barrier formation is investigated as well by retaining electromagnetic effects and its impact found to be negligible for this particular barrier formation mechanism.
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Matsubara, Hiroaki, and Atsushi Tamii. "Quenching of Isovector and Isoscalar Spin-M1 Excitation Strengths in N = Z Nuclei." Frontiers in Astronomy and Space Sciences 8 (July 14, 2021). http://dx.doi.org/10.3389/fspas.2021.667058.
Full textAbstract:
Spin-M1 excitations of nuclei are important for describing neutrino reactions in supernovae or in neutrino detectors since they are allowed transitions mediated by neutral current neutrino interactions. The spin-M1 excitation strength distributions in self-conjugate N=Z nuclei were studied by proton inelastic scattering at forward angles for each of isovector and isoscalar excitations as reported in H. Matsubara et al., Phys. Rev. Lett. 115, 102501 (2015). The experiment was carried out at the Research Center for Nuclear Physics, Osaka University, employing a proton beam at 295 MeV and the high-resolution spectrometer Grand Raiden. The measured cross-section of each excited state was converted to the squared nuclear matrix elements of spin-M1 transitions by applying a unit cross-section method. Comparison with predictions by a shell-model has revealed that isoscalar spin-M1 strengths are not quenched from the prediction although isovector spin-M1 strengths are quenched similarly with Gamow-Teller strengths in charged-current reactions. This finding hints at an important origin of the quenching of the strength relevant to neutrino scattering, that is, the proton-neutron spin-spin correlation in the ground state of the target nucleus. In this manuscript we present the details of the unit cross-section method used in the data analysis and discuss the consistency between the quenching of the isoscalar magnetic moments and that of the isoscalar spin-M1 strengths.
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Kamata, Isaho, Hidekazu Tsuchida, William M. Vetter, and Michael Dudley. "High-Resolution X-ray Topography of Dislocations in 4H-SiC Epilayers." MRS Proceedings 911 (2006). http://dx.doi.org/10.1557/proc-0911-b05-11.
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AbstractSilicon carbide (SiC) substrates and epilayers contain many crystal defects, such as micropipes, screw dislocations, threading edge dislocations (TEDs), basal plane dislocations (BPDs) and stacking faults. To investigate these defects, synchrotron radiation topography is frequently carried out. When the monochromatic synchrotron X-ray topography is taken by the grazing-incidence reflection geometry using 11-28 reflection, screw dislocations, TEDs and BPDs are simultaneously seen and shown as different topographic images [1]. Many studies of dislocations were reported using 11-28 reflections in 4H-SiC [1,2]. Topographic images of the dislocations have been analyzed by the ray-tracing method of computer simulation [3]. However, experimental images of dislocations were not fully matched to the fine structure of simulation images, because of a lack of resolution in recording media: conventional films and nuclear emulsion plates [3]. This time, we report obtaining high-resolution topographic images using a new recording medium, and compare results between the experiment and the computer simulation. Synchrotron topography in 11-28 reflection was carried out at SPring8 applying holography films as high-resolution recording media. The TED images are distinguished as four types, which have ribbon-like features with different rotating angles, through the use of the films. The four different TED images agree well with the computer simulated images which have been reported by Vetter et.al. taking into account of the different Burgers vector directions [3]. By comparing the three topographic images taken at g=-12-18, 11-28 and 2-1-18, we confirmed experimentally that the four types of TED images originated from the difference of Burgers vector directions. We also investigated high-resolution topographic images of elementary screw dislocations, micropipes, and BPDs in 4H-SiC epilayers. The experimental image of screw dislocation fairly matched with simulated image. The fine features in the experimental topographic images of micropipes and BPDs are also compared with the simulated images in detail. [1] T. Ohno, H. Yamaguchi, S. Kuroda, K. Kojima, T. Suzuki, K. Arai: J. cryst. Growth. Vol. 260 (2004) 209. [2] H. Tsuchida, T. Miyanagi, I. Kamata, T. Nakamura, R. Ishii, K. Nakayama and Y.Sugawara: Jpn. J. Appl. Phys. Vol. 25, (2005), L806-808. [3] W. Vetter, H. Tsuchida, I. Kamata, M. Dudley: J. Appl. Cryst. Vol. 38, (2005), 442-447.