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Topic Review
Channelling
Channelling is the process that constrains the path of a charged particle in a crystalline solid. Many physical phenomena can occur when a charged particle is incident upon a solid target, e.g., elastic scattering, inelastic energy-loss processes, secondary-electron emission, electromagnetic radiation, nuclear reactions, etc. All of these processes have cross sections which depend on the impact parameters involved in collisions with individual target atoms. When the target material is homogeneous and isotropic, the impact-parameter distribution is independent of the orientation of the momentum of the particle and interaction processes are also orientation-independent. When the target material is monocrystalline, the yields of physical processes are very strongly dependent on the orientation of the momentum of the particle relative to the crystalline axes or planes. Or in other words, the stopping power of the particle is much lower in certain directions than others. This effect is commonly called the "channelling" effect. It is related to other orientation-dependent effects, such as particle diffraction. These relationships will be discussed in detail later.
  • 496
  • 29 Nov 2022
Biography
Gregory Jaczko
Gregory B. Jaczko (/ˈjɑːskoʊ/; born October 29, 1970, Norristown, Pennsylvania) was a Chairman of the U.S. Nuclear Regulatory Commission (NRC). A physicist with public policy experience in academia and serving on Congressional staffs, he has been deeply interested in the development of nuclear power and its relation to the American public. On May 21, 2012, he announced his resignation pend
  • 496
  • 29 Nov 2022
Topic Review
Terahertz Spectroscopy and Technology
Terahertz spectroscopy detects and controls properties of matter with electromagnetic fields that are in the frequency range between a few hundred gigahertz and several terahertz (abbreviated as THz). In many-body systems, several of the relevant states have an energy difference that matches with the energy of a THz photon. Therefore, THz spectroscopy provides a particularly powerful method in resolving and controlling individual transitions between different many-body states. By doing this, one gains new insights about many-body quantum kinetics and how that can be utilized in developing new technologies that are optimized up to the elementary quantum level. Different electronic excitations within semiconductors are already widely used in lasers, electronic components and computers. At the same time, they constitute an interesting many-body system whose quantum properties can be modified, e.g., via a nanostructure design. Consequently, THz spectroscopy on semiconductors is relevant in revealing both new technological potentials of nanostructures as well as in exploring the fundamental properties of many-body systems in a controlled fashion.
  • 495
  • 25 Oct 2022
Topic Review
Optimization Design Methods for PUT
Sound waves are a form of energy transmission in the mechanical vibration state of an object. Ultrasound is a type of sound wave with a vibration frequency higher than 20 kHz, which cannot be heard by humans. A piezoelectric ultrasonic transducer (PUT) is a device for achieving mutual conversion of mechanical energy and electrical energy. Due to the advantages of high safety and low cost, a PUT has been widely used as the core device for non-destructive testing (NDT), medical imaging, particle manipulation, and flow measurement. The traditional optimization design methods are mainly based on an analytical model, an equivalent circuit model, or a finite element model and the design parameters are adjusted by a trial-and-error method, which relies on the experience of experts and has a relatively low efficiency. Recently, by combining intelligent optimization algorithms, efficient optimization design methods for a PUT have been developed based on a traditional model or a data-driven model, which can effectively improve the design efficiency of a PUT and reduce its development cycle and cost. 
  • 494
  • 13 Jul 2021
Topic Review
Astrobiology Science and Technology for Exploring Planets
Astrobiology Science and Technology for Exploring Planets (ASTEP) was a program established by NASA to sponsor research projects that advance the technology and techniques used in planetary exploration. The objective was to enable the study of astrobiology and to aid the planning of extraterrestrial exploration missions while prioritizing science, technology, and field campaigns.
  • 494
  • 06 Oct 2022
Topic Review
Nano-grating Assisted Light Absorption and MSM-PDs Performance
The nano-grating assisted MSM-PDs are preordained to be decorous for many emerging and existing communication device applications. There have been a significant number of research works conducted on the implementation of nano-gratings, and still, more researches are ongoing to raise the performance of MSM-PDs particularly, in terms of enhancing the light absorption potentialities.
  • 494
  • 15 Dec 2021
Biography
William T. Kane
William T. Kane (September 8, 1932 – September 23, 2008) was a physicist for Corning Incorporated, formerly Corning Glass Works, Inc., in Corning, New York, who held patents in crystallography and heat-sensing technology—developments which contributed to the early processing and manufacture of fiber optics. He was also the Corning representative for the establishment of international standar
  • 494
  • 16 Nov 2022
Topic Review
Non-Targeted Effects of Australian and European Synchrotrons
The Australian Synchrotron (AS) and the European Synchrotron Radiation Facility (ESRF) are best configured for a wide range of biomedical research involving animals and future cancer patients. Due to ultra-high dose rates, treatment doses can be delivered within milliseconds, abiding by FLASH radiotherapy principles. In addition, a homogeneous radiation field can be spatially fractionated into a geometric pattern called microbeam radiotherapy (MRT); a coplanar array of thin beams of microscopic dimensions. Both are clinically promising radiotherapy modalities because they trigger a cascade of biological effects that improve tumor control, while increasing normal tissue tolerance compared to conventional radiation. Synchrotrons can deliver high doses to a very small volume with low beam divergence, thus facilitating the study of non-targeted effects of these novel radiation modalities in both in-vitro and in-vivo models. Non-targeted radiation effects studied at the AS and ESRF include monitoring cell–cell communication after partial irradiation of a cell population (radiation-induced bystander effect, RIBE), the response of tissues outside the irradiated field (radiation-induced abscopal effect, RIAE), and the influence of irradiated animals on non-irradiated ones in close proximity (inter-animal RIBE).
  • 492
  • 19 Apr 2022
Topic Review
PSR J1614–2230
PSR J1614–2230 is a neutron star in a binary system with a white dwarf. It was discovered in 2006 with the Parkes telescope in a survey of unidentified gamma ray sources in the Energetic Gamma Ray Experiment Telescope catalog. PSR J1614–2230 is a millisecond pulsar, a type of neutron star, that spins on its axis roughly 317 times per second, corresponding to a period of 3.15 milliseconds. Like all pulsars, it emits radiation in a beam, similar to a lighthouse. Emission from PSR J1614–2230 is observed as pulses at the spin period of PSR J1614–2230. The pulsed nature of its emission allows for the arrival of individual pulses to be timed. By measuring the arrival time of pulses, astronomers observed the delay of pulse arrivals from PSR J1614–2230 when it was passing behind its companion from the vantage point of Earth. By measuring this delay, known as the Shapiro delay, astronomers determined the mass of PSR J1614–2230 and its companion. The team performing the observations found that the mass of PSR J1614–2230 is 1.97 ± 0.04 M☉. This mass made PSR J1614–2230 the most massive known neutron star at the time of discovery, and rules out many neutron star equations of state that include exotic matter such as hyperons and kaon condensates. In 2013, a slightly higher neutron star mass measurement was announced for PSR J0348+0432, 2.01 ± 0.04 M☉. This confirmed the existence of such massive neutron stars using a different measuring technique.
  • 492
  • 04 Nov 2022
Biography
Yury Romanenko
Yury Viktorovich Romanenko (Russian: Ю́рий Ви́кторович Романе́нко, Jurij Viktorovič Romanenko; born August 1, 1944) is a former Soviet cosmonaut, twice Hero of the Soviet Union (March 16, 1978 and September 26, 1980). Over his career, Yury Romanenko spent a total of 430 days 20 hours 21 minutes 30 seconds in space and 18 hours in space walks.[1] In 1987 he was a reside
  • 491
  • 07 Dec 2022
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