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Development of advanced photon calibrator for Kamioka gravitational wave detector (KAGRA)

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arXiv 2023年

作者： Inoue, Y. Hsieh, B.H. Chen, K.H. Chu, Y.K. Ito, K. Kozakai, C. Shishido, T. Tomigami, Y. Akutsu, T. Haino, S. Izumi, K. Kajita, T. Kanda, N. Lin, C.S. Lin, F.K. Moriwaki, Y. Ogaki, W. Pang, H.F. Sawada, T. Tomaru, T. Suzuki, T. Tsuchida, S. Ushiba, T. Washimi, T. Yamamoto, T. Yokozawa, T. Department of Physics National Central University Taoyuan Zhongli32001 Taiwan Center for High Energy and High Field Physics National Central University Taoyuan Zhongli32001 Taiwan Institute of Physics Academia Sinica Taipei11529 Taiwan High Energy Accelerator Research Organization Ibaraki305-0801 Japan Institute for Cosmic Ray Research The University of Tokyo Chiba277-8582 Japan Molecular Sciences and Technology Taiwan International Graduate Program Academia Sinica National Central University Taipei Taiwan Institute of Atomic and Molecular Science Academia Sinica Taipei10617 Taiwan Department of Physics University of Toyama Toyama930-8555 Japan Kanagawa240-0115 Japan Department of Physics Graduate School of Science Osaka City University Osaka558-8585 Japan Tokyo181-8588 Japan JAXA Institute of Space and Astronautical Science Chuo-ku Kanagawa Sagamihara City252-0222 Japan Department of Physics Graduate School of Science Osaka Metropolitan University Osaka558-8585 Japan Osaka Metropolitan University Osaka558-8585 Japan

The KAGRA cryogenic gravitational-wave observatory has begun joint observation with the worldwide gravitational waves detector network. Precise calibration of the detector response is essential for the parameter estimation of gravitational wave sources. The photon calibrator is the main calibrator in LIGO, Virgo and KAGRA, and we used this calibrator in joint observation 3 on 2020 April with GEO600 in Germany. KAGRA improved the system for joint observation 3 with three unique points: high laser power, power stabilization system, and remote beam position control. KAGRA employs the 20 W laser and divides it into two beams injected on the mirror surface. By using a high-power laser, we can calibrate the response at the kHz region. To control the power of each laser independently, we also installed an optical follower servo for each beam power stabilization. By controlling the optical path of the photon calibrater beam positions with pico-motors, we were able to characterize the rotation response of the detector. We also installed a telephoto camera and QPD to monitor beam position and controlled beam position to optimize mirror response. In this paper, we discussed the statistical error with the result of the relative power noise measurement. We also discussed systematic errors about the power calibration model of photon calibrator and simulation of elastic deformation effect with the finite element analysis. © 2023, CC BY.

关键词： Photons

Thermoluminescence Studies of Pakistani Limestone Pellets for X-Rays: Comparison with Commercial Tld-100 Dosimeter

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SSRN

SSRN 2023年

作者： Mahmood, M. Masood Kakakhel, M. Basim Lee, Junyoung Mirza, Jamal Ahmed Millers, Rodrigo Hernandez Ye, Sung-Joon Islamabad45650 Pakistan Health Physics Division PINSTECH Nilore Islamabad Pakistan Program in Biomedical Radiation Sciences Department of Transdisciplinary Studies Graduate School of Convergence Science and Technology Seoul National University Seoul08826 Korea Republic of Isotope Production Division Pakistan Institute of Nuclear Science and Technology Nilore Islamabad44000 Pakistan Research Institute for Convergence Science Graduate School of Convergence Science and Technology Seoul National University Seoul08826 Korea Republic of Advance Institutes of Convergence Technology Seoul National University Suwon16229 Korea Republic of

With the increased use of ionizing radiations across a spectrum of applications, the quest for identifying low-cost thermoluminescence (TL) materials to be used for radiation dosimetry is of vital importance. Therefore, identification and confirmation of natural materials suitable for radiation dosimetry is an active area of research. Such potential materials must have features like rigidity, insolubility, and chemical inertness etc. besides having additional dosimetric characteristics. One such promising low-cost material can be a limestone having vast deposits in Pakistan. So far, the TL and dosimetric characterization of pellets fabricated with Pakistani limestone and irradiated with X-rays has not been previously reported. All the studied literature has reported powdered form of limestone. The present study reports pelletized limestone and its intercomparison with *** quarried crystalline samples of limestone were hand crushed, sieved and compressed to fabricate pellets of size comparable to standard TLD chips. TL response, kinetic parameters, dose linearity, batch homogeneity, individual sensitivity correction factor (i.e., elemental correction coefficient ECC), lowest detectable dose limit (LDDL), coefficient of variation (COV), energy dependency (for X-ray energy range from 50 kV to 6 MV), and response fading (for a month) were determined and compared with TLD-100. For TL analysis, pellets were irradiated to 250 kV X-rays with a dose of 8 Gy. The pellets exhibited complex TL glow curve showing four peaks (P1, P2, P3 and P4) with a peak temperature of around P1 (90–110°C), P2 (130–170°C), P3 (240–280°C) and P4 (320–350°C) respectively. A dose linearity (with 250 kV X-rays) for 1–10 Gy, was observed while comparing with TLD-100. The pellets showed a linearity while TLD-100 showed supra-linearity in the studied dose range. Tm-Tstop method was applied initially for TL analysis to identify the overlapping peaks of the glow curve followed by Computerized gl

关键词： Thermoluminescence

Lieb-Schultz-Mattis Theorem in Higher Dimensions from Approximate Magnetic Translation Symmetry

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Physical Review Letters 2021年第23期127卷 237204-237204页

作者： Yasuhiro Tada Quantum Matter Program Graduate School of Advanced Science and Engineering Hiroshima University Higashihiroshima Hiroshima 739-8530 Japan and Institute for Solid State Physics University of Tokyo Kashiwa 277-8581 Japan

We prove the Lieb-Schultz-Mattis theorem on the energy spectrum of a general two- or three-dimensional quantum many-body system with the U(1) particle number conservation and translation symmetry. Especially, it is demonstrated that the theorem holds in a system with long-range interactions. To this end, we introduce approximate magnetic translation symmetry under the total magnetic flux Φ=2π instead of the exact translation symmetry, and explicitly construct low energy variational states. The energy spectrum at Φ=2π is shown to agree with that at Φ=0 in the thermodynamic limit, which concludes the Lieb-Schultz-Mattis theorem.

关键词： Quantum statistical mechanics Equilibrium lattice models Strongly correlated systems Lattice models in condensed matter Symmetries in condensed matter Tight-binding model

Electronic-photonic quantum systems on-chip

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Electronic-photonic quantum systems on-chip

Quantum 2.0, QUANTUM 2022

作者： Wang, Imbert Ramesh, Anirudh Kramnik, Danielius Fargas Cabanillas, Josep M. Stojanović, Vladimir Kumar, Prem Popović, Miloš A. Department of Electrical and Computer Engineering Photonics Center Boston University BostonMA02215 United States Graduate Program in Applied Physics Northwestern University EvanstonIL60208 United States Department of Electrical Engineering and Computer Science UC Berkeley BerkeleyCA94720 United States Center for Photonic Communication and Computing Dept. of Electrical and Computer Eng. Northwestern University EvanstonIL60208 United States

We present progress towards realizing electronic-photonic quantum systems on-chip;particularly, entangled photon-pair sources, placing them in the context of previous work, and outlining our vision for mass-producible... 详细信息

ISBN: (纸本)9781957171111

关键词： Quantum entanglement

Determination of Majorana type-phases from the time evolution of lepton numbers

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arXiv 2022年

作者： Benoit, Nicholas J. Kawamura, Yuta Hamada, Saki Morozumi, Takuya Shimizu, Yusuke Yamamoto, Kei Graduate School of Science Hiroshima University Higashi-Hiroshima739-8526 Japan Mie Yokkaichi City Japan Higashi-Hiroshima Japan Physics Program Graduate School of Advanced Science and Engineering Hiroshima University Higashi-Hiroshima739-8526 Japan Core of Research for the Energetic Universe Hiroshima University Higashi-Hiroshima739-8526 Japan Department of Information Kaishi Professional University Niigata950-0916 Japan Faculty of Science and Engineering Department of Physical Science and Materials Engineering Studies in Mathematical Science and Physics Iwate University Japan

We have investigated an approach to determine the Majorana type-phases using the time evolution of lepton family numbers. The Majorana type-phases are related to the orientation of unitarity triangles for the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix, and the Majorana phases α21 and α31. After taking the second-order time derivative of the lepton family number expectation values, the dependencies on the summation of Majorana type-phases can be determined. Thus allowing for the extraction of the orientation of the unitarity triangles and the Majorana phases. We study how to extract the Majorana type-phases and the lightest neutrino mass for three massive neutrinos, and when a neutrino is massless, i.e., m1,3 = 0. Theoretically, our results indicate lepton number can be used to determine the orientation of the PMNS unitarity triangles and the Majorana phases. To show how the Majorana phases and Majorana-type phases are related to the CP violation for leptogenesis at high energy, we first adopt a parametrization where the diagonal elements of the effective Majorana mass matrix at low energy are given by real positive numbers. In this basis, the phase of the off-diagonal elements related to the CP violating phases in PMNS matrix. We explicitly show the relation between the single Majorana phase and the phase of the effective Majorana mass matrix for two generation case of active neutrinos. Then for type I seesaw model with two gauge singlet neutrinos and two families of lepton doublet, we study the effective Majorana mass matrix generated by the seesaw model. We are able to show how the Majorana phase at low energy is related to two CP violating phases in the seesaw model and the relation between Majorana phase at low energy and CP violating phases related to the lepton number asymmetries of the heavy Majorana neutrinos decays is established. © 2022, CC BY.

关键词： Neutrons

Assessment of scoring functions for computational models of protein-protein interfaces

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arXiv 2024年

作者： Sumner, Jacob Meng, Grace Brandt, Naomi Grigas, Alex T. Córdoba, Andrés Shattuck, Mark D. O’Hern, Corey S. Graduate Program in Computational Biology and Bioinformatics Yale University New HavenCT06520 United States Integrated Graduate Program in Physical and Engineering Biology Yale University New HavenCT06520 United States Department of Chemistry Yale University New HavenCT06520 United States Department of Physics Yale University New HavenCT06520 United States Department of Chemistry Duke University DurhamNC27708 United States Department of Physics Duke University DurhamNC27708 United States Benjamin Levich Institute Physics Department City College of New York New YorkNY10031 United States Department of Mechanical Engineering and Materials Science Yale University New HavenCT06520 United States Department of Applied Physics Yale University New HavenCT06520 United States

A goal of computational studies of protein-protein interfaces (PPIs) is to predict the binding site between two monomers that form a heterodimer. The simplest version of this problem is to rigidly re-dock the bound forms of the monomers, which involves generating computational models of the heterodimer and then scoring them to determine the most native-like models. Scoring functions have been assessed previously using rank- and classification-based metrics, however, these methods are sensitive to the number and quality of models in the scoring function training set. We assess the accuracy of seven PPI scoring functions by comparing their scores to a measure of structural similarity to the x-ray crystal structure (i.e. the DockQ score) for a non-redundant set of heterodimers from the Protein Data Bank. For each heterodimer, we generate re-docked models uniformly sampled over DockQ and calculate the Spearman correlation between the PPI scores and DockQ. For some targets, the scores and DockQ are highly correlated;however, for many targets, there are weak correlations. Several physical features can explain the difference between difficult- and easy-to-score targets. For example, strong correlations exist between the score and DockQ for targets with highly intertwined monomers and many interface contacts. We also develop a new score based on only three physical features that matches or exceeds the performance of current PPI scoring functions. These results emphasize that PPI prediction can be improved by focusing on correlations between the PPI score and DockQ and incorporating more discriminating physical features into PPI scoring functions. © 2024, CC BY.

关键词： Monomers

Effect of chemical and biological additives on production of biogas from coffee pulp silage

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Scientific Reports 2023年第1期13卷 1-11页

作者： Getachew, Mengizam Tsegaye Hiruy, Andualem Mekonnen Mazharuddin, Majid Mohiuddin Mamo, Tadios Tesfaye Feseha, Temesgen Aragaw Mekonnen, Yedilfana Setarge Center for Environmental Science College of Natural and Computational Sciences Addis Ababa University Addis Ababa Ethiopia Institute of Atomic and Molecular Sciences Academia Sinica Taipei Taiwan Nano Science and Technology Program Taiwan International Graduate Program Academia Sinica Taipei 11529 Taiwan Institute of Physics Academia Sinica Taipei 11529 Taiwan Department of Chemistry National Taiwan University Taipei 10617 Taiwan

Energy is the foundation of the global economy and is essential to human survival. Nevertheless, more than 60% of it comes from fossil fuels. That is not a replenished and scarce source. However, a sizable amount of organic waste is generated every minute throughout the world and can be used as a raw material to produce renewable energy. Among them, Coffee processing generates a huge amount of solid and liquid waste that is organic and can serve as raw material for biofuel production. Since coffee beans and powder are Ethiopia’s main exports, coffee pulp is easily accessible. Therefore, the main goal of this project is to convert this waste, which largely consists of organic materials, into a valuable product called Methane. The purity and yield of methane productivity are significantly influenced by the type of additives we use. This work systematically investigates the effect of chemical and biological additives on the productivity and purity of the Biogas from the coffee pulp silage in batch systems under mesophilic temperature (38 °C) for different ensiling periods and additive proportions. The chemical additives recorded the maximum biogas production (2980 ml) at an ensiling period of 40 days with high purity of about 70% biogas. The minimum Biogas was recorded at the ensiling period of 10 days by the control (T1) treatments, which was 634 ml. This work proves that biological additives produced the highest quality and quantity of Biogas from coffee silage. © 2023, The Author(s).

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Unnecessary risks created by uncontrolled rocket reentries

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arXiv 2022年

作者： Byers, Michael Wright, Ewan Boley, Aaron Byers, Cameron Department of Political Science University of British Columbia VancouverBC Canada Interdisciplinary Studies Graduate Program University of British Columbia VancouverBC Canada Department of Physics and Astronomy University of British Columbia VancouverBC Canada Bachelor of Engineering Program University of Victoria VictoriaBC Canada

In 2020, over 60% of launches to low Earth orbit resulted in one or more rocket bodies being abandoned in orbit and eventually returning to Earth in an uncontrolled manner. When they do so, between 20 and 40% of their mass survives the heat of atmospheric reentry. Many of the surviving pieces are heavy enough to pose serious risks to people, on land, at sea, and in airplanes. There is no international consensus on the acceptable level of risk from reentering space objects. This is sometimes a point of contention, such as when a 20 tonne Long March 5B core stage made an uncontrolled reentry in May 2021. Some regulators, including the US, France, and ESA, have implemented a 1 in 10, 000 acceptable casualty risk (i.e., statistical threat to human life) threshold from reentering space objects. We argue that this threshold ignores the cumulative effect of the rapidly increasing number of rocket launches. It also fails to address low risk, high consequence outcomes, such as a rocket stage crashing into a high-density city or a large passenger aircraft. In the latter case, even a small piece could cause hundreds of casualties. Compounding this, the threshold is frequently ignored or waived when the costs of adherence are deemed excessive. We analyse the rocket bodies that reentered the atmosphere from 1992-2021 and model the associated cumulative casualty expectation. We then extrapolate this trend into the near future (2022-2032), modelling the potential risk to the global population from uncontrolled rocket body reentries. We also analyse the population of rocket bodies that are currently in orbit and expected to deorbit soon, and find that the risk distribution is significantly weighted to latitudes close to the equator. This represents a disproportionate burden of casualty risk imposed on the countries of the Global South by major spacefaring countries. Modern rockets have reignitable engines, allowing controlled reentries into remote areas of the oceans. This, combine

关键词： Rockets

Recent developments in the computational study of protein structural and vibrational energy dynamics

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Biophysical Reviews 2020年第2期12卷 317-322页

作者： Leitner, David M. Yamato, Takahisa Department of Chemistry and Chemical Physics Program University of Nevada Reno 89557 NV United States Graduate School of Science Division of Material Science Nagoya University Furo-cho Chikusa-ku Nagoya 464-8602 Japan

Recent developments in the computational study of energy transport in proteins are reviewed, including advances in both methodology and applications. The concept of energy exchange network (EEN) is discussed, and a recent calculation of EENs for the allosteric protein FixL is reviewed, which illustrates how residues and protein regions involved in the allosteric transition can be identified. Recent work has examined relations between EENs and protein dynamics as well as structure. We review some of the computational studies carried out on several proteins that explore connections between energy conductivity across polar contacts in proteins and between proteins and water and equilibrium dynamics of the contacts, and we discuss some of the recent experimental work that addresses this topic. © 2020, International Union for Pure and Applied Biophysics (IUPAB) and Springer-Verlag GmbH Germany, part of Springer Nature.

关键词： Energy exchange network Energy transport FixL Hemoglobin Proteins