WorldWideScience

Sample records for hard-core semiconductor physicist

  1. Physicists

    CERN Document Server

    Snow, CP

    2010-01-01

    C P Snow's sketches of famous physicists and explanation of how atomic weapons were developed gives an overview of science often lacking. This study provides us with hope for the future as well as anecdotes from history.

  2. Vapour-liquid equilibria of the hard core Yukawa fluid

    NARCIS (Netherlands)

    Smit, B.; Frenkel, D.

    1991-01-01

    Techniques which extend the range of applicability of the Gibbs ensemble technique for particles which interact with a hard core potential are described. The power of the new technique is demonstrated in a numerical study of the vapour-liquid coexistence curve of the hard core Yukawa fluid.

  3. Soft shell hard core concept for aircraft impact resistant design

    International Nuclear Information System (INIS)

    Chen, C.; Rieck, P.J.

    1978-01-01

    For nuclear power plants sited in the vicinity of airports, the hypothetical events of aircraft impact have to be designed for. The conventional design concept is to strengthen the exterior structure to resist the impact induced force. The stiffened structures have two (2) disadvantages; one is the high construction cost, and the other is the high reaction force induced as well as the vibrational effects on the interior equipment and piping systems. This new soft shell hard core concept can relieve the above shortcomings. In this concept, the essential equipment required for safety are installed inside the hard core area for protection and the non-essential equipment are maintained between the hard core and soft shell area. During a hypothetical impact event, the soft shell will collapse locally and absorb large amounts of kinetic energy; hence, it reduces the reaction force and the vibrational effects. The design and analysis of the soft shell concept are discussed. (Author)

  4. On Maximal Hard-Core Thinnings of Stationary Particle Processes

    Science.gov (United States)

    Hirsch, Christian; Last, Günter

    2018-02-01

    The present paper studies existence and distributional uniqueness of subclasses of stationary hard-core particle systems arising as thinnings of stationary particle processes. These subclasses are defined by natural maximality criteria. We investigate two specific criteria, one related to the intensity of the hard-core particle process, the other one being a local optimality criterion on the level of realizations. In fact, the criteria are equivalent under suitable moment conditions. We show that stationary hard-core thinnings satisfying such criteria exist and are frequently distributionally unique. More precisely, distributional uniqueness holds in subcritical and barely supercritical regimes of continuum percolation. Additionally, based on the analysis of a specific example, we argue that fluctuations in grain sizes can play an important role for establishing distributional uniqueness at high intensities. Finally, we provide a family of algorithmically constructible approximations whose volume fractions are arbitrarily close to the maximum.

  5. The hard-core model on random graphs revisited

    International Nuclear Information System (INIS)

    Barbier, Jean; Krzakala, Florent; Zhang, Pan; Zdeborová, Lenka

    2013-01-01

    We revisit the classical hard-core model, also known as independent set and dual to vertex cover problem, where one puts particles with a first-neighbor hard-core repulsion on the vertices of a random graph. Although the case of random graphs with small and very large average degrees respectively are quite well understood, they yield qualitatively different results and our aim here is to reconciliate these two cases. We revisit results that can be obtained using the (heuristic) cavity method and show that it provides a closed-form conjecture for the exact density of the densest packing on random regular graphs with degree K ≥ 20, and that for K > 16 the nature of the phase transition is the same as for large K. This also shows that the hard-code model is the simplest mean-field lattice model for structural glasses and jamming

  6. Nuclear many-body problem with repulsive hard core interactions

    Energy Technology Data Exchange (ETDEWEB)

    Haddad, L M

    1965-07-01

    The nuclear many-body problem is considered using the perturbation-theoretic approach of Brueckner and collaborators. This approach is outlined with particular attention paid to the graphical representation of the terms in the perturbation expansion. The problem is transformed to centre-of-mass coordinates in configuration space and difficulties involved in ordinary methods of solution of the resulting equation are discussed. A new technique, the 'reference spectrum method', devised by Bethe, Brandow and Petschek in an attempt to simplify the numerical work in presented. The basic equations are derived in this approximation and considering the repulsive hard core part of the interaction only, the effective mass is calculated at high momentum (using the same energy spectrum for both 'particle' and 'hole' states). The result of 0.87m is in agreement with that of Bethe et al. A more complete treatment using the reference spectrum method in introduced and a self-consistent set of equations is established for the reference spectrum parameters again for the case of hard core repulsions. (author)

  7. Pair Formation of Hard Core Bosons in Flat Band Systems

    Science.gov (United States)

    Mielke, Andreas

    2018-05-01

    Hard core bosons in a large class of one or two dimensional flat band systems have an upper critical density, below which the ground states can be described completely. At the critical density, the ground states are Wigner crystals. If one adds a particle to the system at the critical density, the ground state and the low lying multi particle states of the system can be described as a Wigner crystal with an additional pair of particles. The energy band for the pair is separated from the rest of the multi-particle spectrum. The proofs use a Gerschgorin type of argument for block diagonally dominant matrices. In certain one-dimensional or tree-like structures one can show that the pair is localised, for example in the chequerboard chain. For this one-dimensional system with periodic boundary condition the energy band for the pair is flat, the pair is localised.

  8. Absence of positive eigenvalues for hard-core N-body systems

    DEFF Research Database (Denmark)

    Ito, K.; Skibsted, Erik

    We show absence of positive eigenvalues for generalized 2-body hard-core Schrödinger operators under the condition of bounded strictly convex obstacles. A scheme for showing absence of positive eigenvalues for generalized N-body hard-core Schrödinger operators, N≥ 2, is presented. This scheme inv...

  9. Semiconductor

    International Nuclear Information System (INIS)

    2000-01-01

    This book deals with process and measurement of semiconductor. It contains 20 chapters, which goes as follows; semiconductor industry, introduction of semiconductor manufacturing, yield of semiconductor process, materials, crystal growth and a wafer forming, PN, control pollution, oxidation, photomasking photoresist chemistry, photomasking technologies, diffusion and ion injection, chemical vapor deposition, metallization, wafer test and way of evaluation, semiconductor elements, integrated circuit and semiconductor circuit technology.

  10. The ASN imposes on EDF complementary requirements for the setting of the hard-core unit

    International Nuclear Information System (INIS)

    Anon.

    2014-01-01

    In January 2014, the ASN (French Authority for Nuclear Safety) published a list of 19 decisions concerning the implementation of a 'post-Fukushima' hard-core unit in each EDF nuclear power plant. The purpose of the hard-core unit is to have structures and equipment able to resist very extreme events and able to assure the vital functions necessary for the reactor safety. The 19 decisions detail the rules for the design of the hard-core unit. For example the hard-core unit will have to resist earthquakes for which the probability of occurrence is about 1 every 20.000 years while the probability taking into account for the design of the reactor is only 1 every 1000 or 10.000 years

  11. Solitons in a hard-core bosonic system: Gross–Pitaevskii type and ...

    Indian Academy of Sciences (India)

    2015-10-20

    Oct 20, 2015 ... Solitons in a hard-core bosonic system: Gross–Pitaevskii type and beyond ... the corresponding class of magnetic solitons in Heisenberg spin chains with different types of anisotropy. ... Pramana – Journal of Physics | News.

  12. Physicists' boycott

    CERN Document Server

    Charap, John M

    1980-01-01

    In CERN, scientists had taken action to boycott cooperation with their Soviet counterparts. This is in protest at the detention of the distinguished Russian particle accelerator physicist, Dr Yuri Orlov; 8,000 scientists from more than 40 countires have signed similar pledges

  13. Induced supersolidity in a mixture of normal and hard-core bosons

    International Nuclear Information System (INIS)

    Mishra, Tapan; Das, B. P.; Pai, Ramesh V.

    2010-01-01

    We present a scenario where a supersolid is induced in one of the components of a mixture of two species bosonic atoms where there are no long-range interactions. We study a system of normal and hard-core boson mixture with only the former possessing long-range interactions. We consider three cases: the first where the total density is commensurate and the other two where it is incommensurate to the lattice. By suitable choices of the densities of normal and hard-core bosons and the interaction strengths between them, we predict that the charge density wave and the supersolid orders can be induced in the hard-core species as a result of the competing interatomic interactions.

  14. Soft Skills: The New Curriculum for Hard-Core Technical Professionals

    Science.gov (United States)

    Bancino, Randy; Zevalkink, Claire

    2007-01-01

    In this article, the authors talk about the importance of soft skills for hard-core technical professionals. In many technical professions, the complete focus of education and training is on technical topics either directly or indirectly related to a career or discipline. Students are generally required to master various mathematics skills,…

  15. Understanding Why Students Participate in Multiple Surveys: Who are the Hard-Core Responders?

    Science.gov (United States)

    Porter, Stephen R.; Whitcomb, Michael E.

    2004-01-01

    What causes a student to participate in a survey? This paper looks at survey response across multiple surveys to understand who the hard-core survey responders and non-responders are. Students at a selective liberal arts college were administered four different surveys throughout the 2002-2003 academic year, and we use the number of surveys…

  16. Matérn's hard core models of types I and II with arbitrary compact grains

    DEFF Research Database (Denmark)

    Kiderlen, Markus; Hörig, Mario

    Matérn's classical hard core models can be interpreted as models obtained from a stationary marked Poisson process by dependent thinning. The marks are balls of fixed radius, and a point is retained when its associated ball does not hit any other balls (type I) or when its random birth time is st...... of this model with the process of intact grains of the dead leaves model and the Stienen model leads to analogous results for the latter....

  17. Emergence of quasicondensates of hard-core bosons at finite momentum

    International Nuclear Information System (INIS)

    Rigol, Marcos; Muramatsu, Alejandro

    2004-01-01

    An exact treatment of the nonequilibrium dynamics of hard-core bosons on one-dimensional lattices shows that, starting from a pure Fock-state, quasi-long-range correlations develop dynamically, and lead to the formation of quasicondensates at finite momenta. Scaling relations characterizing the quasicondensate and the dynamics of its formation are obtained. The relevance of our findings for atom lasers with full control of the wavelength by means of a lattice is discussed

  18. Bridge density functional approximation for non-uniform hard core repulsive Yukawa fluid

    International Nuclear Information System (INIS)

    Zhou Shiqi

    2008-01-01

    In this work, a bridge density functional approximation (BDFA) (J. Chem. Phys. 112, 8079 (2000)) for a non-uniform hard-sphere fluid is extended to a non-uniform hard-core repulsive Yukawa (HCRY) fluid. It is found that the choice of a bulk bridge functional approximation is crucial for both a uniform HCRY fluid and a non-uniform HCRY fluid. A new bridge functional approximation is proposed, which can accurately predict the radial distribution function of the bulk HCRY fluid. With the new bridge functional approximation and its associated bulk second order direct correlation function as input, the BDFA can be used to well calculate the density profile of the HCRY fluid subjected to the influence of varying external fields, and the theoretical predictions are in good agreement with the corresponding simulation data. The calculated results indicate that the present BDFA captures quantitatively the phenomena such as the coexistence of solid-like high density phase and low density gas phase, and the adsorption properties of the HCRY fluid, which qualitatively differ from those of the fluids combining both hard-core repulsion and an attractive tail. (condensed matter: structure, thermal and mechanical properties)

  19. Meaningful timescales from Monte Carlo simulations of particle systems with hard-core interactions

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Liborio I., E-mail: liborio78@gmail.com

    2016-12-01

    A new Markov Chain Monte Carlo method for simulating the dynamics of particle systems characterized by hard-core interactions is introduced. In contrast to traditional Kinetic Monte Carlo approaches, where the state of the system is associated with minima in the energy landscape, in the proposed method, the state of the system is associated with the set of paths traveled by the atoms and the transition probabilities for an atom to be displaced are proportional to the corresponding velocities. In this way, the number of possible state-to-state transitions is reduced to a discrete set, and a direct link between the Monte Carlo time step and true physical time is naturally established. The resulting rejection-free algorithm is validated against event-driven molecular dynamics: the equilibrium and non-equilibrium dynamics of hard disks converge to the exact results with decreasing displacement size.

  20. Critical parameters of hard-core Yukawa fluids within the structural theory

    Science.gov (United States)

    Bahaa Khedr, M.; Osman, S. M.

    2012-10-01

    A purely statistical mechanical approach is proposed to account for the liquid-vapor critical point based on the mean density approximation (MDA) of the direct correlation function. The application to hard-core Yukawa (HCY) fluids facilitates the use of the series mean spherical approximation (SMSA). The location of the critical parameters for HCY fluid with variable intermolecular range is accurately calculated. Good agreement is observed with computer simulation results and with the inverse temperature expansion (ITE) predictions. The influence of the potential range on the critical parameters is demonstrated and the universality of the critical compressibility ratio is discussed. The behavior of the isochoric and isobaric heat capacities along the equilibrium line and the near vicinity of the critical point is discussed in details.

  1. Low-Temperature Crystal Structures of the Hard Core Square Shoulder Model

    Directory of Open Access Journals (Sweden)

    Alexander Gabriëlse

    2017-11-01

    Full Text Available In many cases, the stability of complex structures in colloidal systems is enhanced by a competition between different length scales. Inspired by recent experiments on nanoparticles coated with polymers, we use Monte Carlo simulations to explore the types of crystal structures that can form in a simple hard-core square shoulder model that explicitly incorporates two favored distances between the particles. To this end, we combine Monte Carlo-based crystal structure finding algorithms with free energies obtained using a mean-field cell theory approach, and draw phase diagrams for two different values of the square shoulder width as a function of the density and temperature. Moreover, we map out the zero-temperature phase diagram for a broad range of shoulder widths. Our results show the stability of a rich variety of crystal phases, such as body-centered orthogonal (BCO lattices not previously considered for the square shoulder model.

  2. Theory of deep inelastic neutron scattering: Hard-core perturbation theory

    International Nuclear Information System (INIS)

    Silver, R.N.

    1988-01-01

    Details are presented of a new many-body theory for deep inelastic neutron scattering (DINS) experiments to measure momentum distributions in quantum fluids and solids. The high-momentum and energy-transfer scattering law in helium is shown to be a convolution of the impulse approximation with a final-state broadening function which depends on the scattering phase shifts and the radial distribution function. The predicted broadening satisfies approximate Y scaling, is neither Lorentzian nor Gaussian, and obeys the f, ω 2 , and ω 3 sum rules. The derivation uses a combination of Liouville perturbation theory, projection superoperators, and semiclassical methods which I term ''hard-core perturbation theory.'' A review is presented of the predictions of prior theories for DINS experiments in relation to the present work. A subsequent paper will present massive numerical predictions and a discussion of DINS experiments on superfluid 4 He

  3. Diffusion-limited reactions of hard-core particles in one dimension

    Science.gov (United States)

    Bares, P.-A.; Mobilia, M.

    1999-02-01

    We investigate three different methods to tackle the problem of diffusion-limited reactions (annihilation) of hard-core classical particles in one dimension. We first extend an approach devised by Lushnikov [Sov. Phys. JETP 64, 811 (1986)] and calculate for a single species the asymptotic long-time and/or large-distance behavior of the two-point correlation function. Based on a work by Grynberg and Stinchcombe [Phys. Rev. E 50, 957 (1994); Phys. Rev. Lett. 74, 1242 (1995); 76, 851 (1996)], which was developed to treat stochastic adsorption-desorption models, we provide in a second step the exact two-point (one- and two-time) correlation functions of Lushnikov's model. We then propose a formulation of the problem in terms of path integrals for pseudo- fermions. This formalism can be used to advantage in the multispecies case, especially when applying perturbative renormalization group techniques.

  4. Thermodynamic equivalence between the Lennard-Jones and hard-core attractive Yukawa systems

    International Nuclear Information System (INIS)

    Kadiri, Y.; Albaki, R.; Bretonnet, J.L.

    2008-01-01

    The investigation of the thermodynamic properties of the Lennard-Jones (LJ) fluid is made by means of a system of particles interacting with a potential of hard-core plus attractive Yukawa tail (HCY). Due to the similarity between the LJ potential and the HCY potential in its overall form, it is worthwhile seeking to approximate the LJ potential in much the same way that the hard-sphere reference potential has been so used. The study consists in describing the thermodynamics of the LJ fluid in terms of the equivalent HCY system, whose the properties are known accurately, by means of mapping the thermodynamic quantities for the HCY potential parameters. The method is feasible owing to a convenient analytical expression of the Helmholtz free energy from the mean-spherical approximation expanded in power of the inverse temperature. Two different procedures are used to determine the parameters of the HCY potential as a function of the thermodynamic states: one is based on the simultaneous fits of pressure and internal energy of the LJ system and the other uses the concept of collision frequency. The reasonable homogeneity of the results in both procedures of mapping makes that the HCY potential is a very good reference system, whose the proposed theoretical expressions can be used confidently to predict the thermodynamic properties of more realistic potentials

  5. Self-Organization Observed in Numerical Simulations of a Hard-Core Diffuse Z Pinch

    International Nuclear Information System (INIS)

    Makhin, V; Siemon, R E; Bauer, B S; Esaulov, A; Lindemuth, I R; Ryutov, D D; Sheehey, P T; Sotnikov, V I

    2005-04-01

    The evolution of an unstable plasma profile into a stable profile, which we term self-organization, appears to be a robust process. Although it was not termed self organization, the same effect has been noted in past simulations with the same code. The result has been made easier to discern by the introduction of z-averaged profiles. A recent report of PIC simulations in the hard-core z-pinch configuration also shows self-organization. Figures 3 and 4 in Reference 21 show how pressure profiles in a low-β PIC simulation relax from unstable to stable. The non-linear evolution of the interchange motion has been studied under controlled initial conditions that result in exponential growth of a mode with a prescribed axial wavelength. An interesting feature of such growth is an abrupt transition from coherent to incoherent motion, after which the z-averaged pressure, current, and temperature profiles become quasi stationary. According to our understanding of MAGO experiments, the observed plasma behavior is consistent with the expectation of self-organization, but the diagnostics are not sufficiently detailed thus far to make a definite conclusion. The results of this simulations reported in this paper add motivation to planned experiments on an inverse pinch at UNR

  6. Non-Abelian fractional quantum Hall states for hard-core bosons in one dimension

    Science.gov (United States)

    Paredes, Belén

    2012-05-01

    I present a family of one-dimensional bosonic liquids analogous to non-Abelian fractional quantum Hall states. A new quantum number is introduced to characterize these liquids, the chiral momentum, which differs from the usual angular or linear momentum in one dimension. As their two-dimensional counterparts, these liquids minimize a k-body hard-core interaction with the minimum total chiral momentum. They exhibit global order, with a hidden organization of the particles in k identical copies of a one-dimensional Laughlin state. For k=2 the state is a p-wave paired phase corresponding to the Pfaffian quantum Hall state. By imposing conservation of the total chiral momentum, an exact parent Hamiltonian is derived which involves long-range tunneling and interaction processes with an amplitude decaying with the chord distance. This family of non-Abelian liquids is shown to be in formal correspondence with a family of spin-(k)/(2) liquids which are total singlets made out of k indistinguishable resonating valence bond states. The corresponding spin Hamiltonians are obtained.

  7. Nuclear Physicists in Finance

    Science.gov (United States)

    Mattoni, Carlo

    2017-01-01

    The financial services industry presents an interesting alternative career path for nuclear physicists. Careers in finance typically offer intellectual challenge, a fast pace, high caliber colleagues, merit-based compensation with substantial upside, and an opportunity to deploy skills learned as a physicist. Physicists are employed at a wide range of financial institutions on both the ``buy side'' (hedge fund managers, private equity managers, mutual fund managers, etc.) and the ``sell side'' (investment banks and brokerages). Historically, physicists in finance were primarily ``quants'' tasked with applying stochastic calculus to determine the price of financial derivatives. With the maturation of the field of derivative pricing, physicists in finance today find work in a variety of roles ranging from quantification and management of risk to investment analysis to development of sophisticated software used to price, trade, and risk manage securities. Only a small subset of today's finance careers for physicists require the use of advanced math and practically none provide an opportunity to tinker with an apparatus, yet most nevertheless draw on important skills honed during the training of a nuclear physicist. Intellectually rigorous critical thinking, sophisticated problem solving, an attention to minute detail and an ability to create and test hypotheses based on incomplete information are key to both disciplines.

  8. Oxide semiconductors

    CERN Document Server

    Svensson, Bengt G; Jagadish, Chennupati

    2013-01-01

    Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. Originally widely known as the ""Willardson and Beer"" Series, it has succeeded in publishing numerous landmark volumes and chapters. The series publishes timely, highly relevant volumes intended for long-term impact and reflecting the truly interdisciplinary nature of the field. The volumes in Semiconductors and Semimetals have been and will continue to be of great interest to physicists, chemists, materials scientists, and device engineers in academia, scient

  9. Physicists produce first antiatom

    CERN Multimedia

    Watson, A

    1996-01-01

    Researchers at the European Center for Particle Physics (CERN) created 11 atoms of antihydrogen using the Low-Energy Antiproton Ring. Physicists forecast that the creation of the first antiatoms will aid in the understanding of antimatter.

  10. Are physicists useful?

    CERN Multimedia

    Ridley, B

    2001-01-01

    Article arguing that physicists need to be more than experts in their fields. They should develop their business, team-work and communication skills if they want to prove their worth to industry (1 page).

  11. Definition of a post-Fukushima hard core for EDF's PWRs: objectives, content and associated requirements

    International Nuclear Information System (INIS)

    2014-01-01

    After having recalled the implementation of the additional safety assessments (ECS) on the French nuclear reactors after the Fukushima accident, and that, after these assessments, ASN asked EDF to implement a 'hard core of robust material and organisational measures' which aim at preventing an accident with a core fusion or at limiting its progress, at limiting massive radioactive releases, and at enabling the operator to perform his required missions in crisis management, this report indicates the objectives of this hard core, and discusses the material measures proposed by EDF. These measures concern the exploited reactors and the EPR Flamanville 3, the pools present in the fuel and reactor buildings. It also discusses the requirements associated with these material measures, notably with respect to earthquake, flooding or other extreme events

  12. Nonequilibrium dynamics of one-dimensional hard-core anyons following a quench: complete relaxation of one-body observables.

    Science.gov (United States)

    Wright, Tod M; Rigol, Marcos; Davis, Matthew J; Kheruntsyan, Karén V

    2014-08-01

    We demonstrate the role of interactions in driving the relaxation of an isolated integrable quantum system following a sudden quench. We consider a family of integrable hard-core lattice anyon models that continuously interpolates between noninteracting spinless fermions and strongly interacting hard-core bosons. A generalized Jordan-Wigner transformation maps the entire family to noninteracting fermions. We find that, aside from the singular free-fermion limit, the entire single-particle density matrix and, therefore, all one-body observables relax to the predictions of the generalized Gibbs ensemble (GGE). This demonstrates that, in the presence of interactions, correlations between particles in the many-body wave function provide the effective dissipation required to drive the relaxation of all one-body observables to the GGE. This relaxation does not depend on translational invariance or the tracing out of any spatial domain of the system.

  13. Women Physicists Speak Again

    Science.gov (United States)

    Ivie, Rachel; Guo, Stacy

    2005-10-01

    More than 1350 women physicists from more than 70 countries responded to a survey designed to identify issues important to women in physics. Women physicists had many areas of concern, notably discrimination and career/family balance. However, they also had many successes in physics. The majority would choose physics again and felt that they had progressed in their careers at least as quickly as their colleagues. Many spoke eloquently about their love of physics, the support they had received from others, and about their own determination and hard work.

  14. Abstract algebra for physicists

    International Nuclear Information System (INIS)

    Zeman, J.

    1975-06-01

    Certain recent models of composite hadrons involve concepts and theorems from abstract algebra which are unfamiliar to most theoretical physicists. The algebraic apparatus needed for an understanding of these models is summarized here. Particular emphasis is given to algebraic structures which are not assumed to be associative. (2 figures) (auth)

  15. Fermilab Education: Physicists

    Science.gov (United States)

    Search Education and Outreach: Resources and Opportunties for Fermilab employees and Users A variety of resources and opportunities are available for physicists interested in education and outreach (For general Data (6–12) Physical Science/Physics Instructional Resources (K–12) US Particle Physics Education and

  16. Physicists epoch and personalities

    CERN Document Server

    Feinberg, E L; Leonidov, A V

    2011-01-01

    The book is a collection of memoirs on famous Soviet physicists of the 20th century, such as Tamm, Vavilov, Sakharov, Landau and others. The narrative is situated within a remarkably well-described historical, cultural and social context. Of special interest are the chapters devoted to Soviet and German atomic projects.

  17. Exact solutions of the Schrodinger equation with the position-dependent mass for a hard-core potential

    International Nuclear Information System (INIS)

    Dong Shihai; Lozada-Cassou, M.

    2005-01-01

    The exact solutions of two-dimensional Schrodinger equation with the position-dependent mass for a hard-core potential are obtained. The eigenvalues related to the position-dependent masses μ 1 and μ 2 , the potential well depth V 0 and the effective range r 0 can be calculated by the boundary condition. We generalize this quantum system to three-dimensional case. The special cases for l=0,1 are studied in detail. For l=0 and c=0, we find that the energy levels will increase with the parameters μ 2 , V 0 and r 0 if μ 1 >μ 2

  18. Charge order-superfluidity transition in a two-dimensional system of hard-core bosons and emerging domain structures

    Science.gov (United States)

    Moskvin, A. S.; Panov, Yu. D.; Rybakov, F. N.; Borisov, A. B.

    2017-11-01

    We have used high-performance parallel computations by NVIDIA graphics cards applying the method of nonlinear conjugate gradients and Monte Carlo method to observe directly the developing ground state configuration of a two-dimensional hard-core boson system with decrease in temperature, and its evolution with deviation from a half-filling. This has allowed us to explore unconventional features of a charge order—superfluidity phase transition, specifically, formation of an irregular domain structure, emergence of a filamentary superfluid structure that condenses within of the charge-ordered phase domain antiphase boundaries, and formation and evolution of various topological structures.

  19. Equation of state of a hard core fluid with a two-Yukawa tail: toward a simple analytic theory

    International Nuclear Information System (INIS)

    Jedrzejek, C.

    1980-01-01

    Thermodynamic properties of simple fluids are calculated using variational theory for a system of hard-core potential with a two-Yukawa tail. Likewise one Yukawa-tail case the working formulas are analytic. Five parameters of the two Yukawa system are chosen so as to get the best fit to a real argon potential or an ''argon-like'' Lennard-Jones potential. The results are fairly good in light of the extreme simplicity of the method. The discrepancies result from using the variational method and a different shape of Yukawa type potential in comparision to the real argon and Lennard-Jones potentials. (author)

  20. Mathematics for physicists

    CERN Document Server

    Martin, B R

    2015-01-01

    Mathematics for Physicists is a relatively short volume covering all the essential mathematics needed for a typical first degree in physics, from a starting point that is compatible with modern school mathematics syllabuses. Early chapters deliberately overlap with senior school mathematics, to a degree that will depend on the background of the individual reader, who may quickly skip over those topics with which he or she is already familiar. The rest of the book covers the mathematics that is usually compulsory for all students in their first two years of a typical university physics degree, plus a little more. There are worked examples throughout the text, and chapter-end problem sets. Mathematics for Physicists features: * Interfaces with modern school mathematics syllabuses * All topics usually taught in the first two years of a physics degree * Worked examples throughout * Problems in every chapter, with answers to selected questions at the end of the book and full solutions on a website This text will ...

  1. Euler as Physicist

    CERN Document Server

    Suisky, Dieter

    2008-01-01

    "Euler as Physicist" analyzes the exceptional role of Leonhard Euler (1707 - 1783) in the history of science and emphasizes especially his fundamental contributions to physics. Although Euler is famous as the leading mathematician of the 18th century, his contributions to physics are as important for their innovative methods and solutions. Several books are devoted to Euler as mathematician, but none to Euler as physicist, like in this book. Euler’s contributions to mechanics are rooted in his life-long plan presented in two volume treatise programmatically entitled "Mechanics or the science of motion analytically demonstrated". Published in 1736, Euler’s treatise indicates the turn over from the traditional geometric representation of mechanics to a new approach. In writing Mechanics Euler did the first step to put the plan and his completion into practice through 1760. It is of particular interest to study how Euler made immediate use of his mathematics for mechanics and coordinated his progress in math...

  2. Physicists in the Wild

    Science.gov (United States)

    Miller, Michael L.

    2017-09-01

    Startups and large corporations are full of physicists, many hiding in plain sight. Why? I will discuss the strong parallels between basic research in nuclear/particle physics, founding teams at great startups, and leaders at some of the world's largest corporations. How big are these opportunities (mission and capital), and what can we do to help prepare more physicists for such roles? I will provide lessons learned from my winding career that began at the NSCL as a philosophy undergrad, proceeded through a PhD, postdoc and brief stint as faculty, and continued through the founding of an early cloud computing startup, a sale to IBM, and the founding of one of Silicon Valley's most active venture capital firms.

  3. Young physicists' forum

    International Nuclear Information System (INIS)

    Adams, T.

    2001-01-01

    The Young Physicists' Forum was an opportunity for the younger members of the particle-physics community to gather at Snowmass 2001 and to study and debate major issues that face the field over the next twenty years. Discussions were organized around three major topics: outreach and education, the impact of globalization, and building a robust and balanced field. We report on the results of these discussions, as presented on July 17, 2001

  4. Physicist or computer specialist?

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, J S [University College Hospital, London (United Kingdom)

    1966-06-15

    Since to most clinicians physical and computer science are two of the great mysteries of the world, the physicist in a hospital is expected by clinicians to be fully conversant with, and competent to make profound pronouncements on, all methods of computing. specific computing problems, and the suitability of computing machinery ranging from desk calculators to Atlas. This is not surprising since the proportion of the syllabus devoted to physics and mathematics in an M. B. degree is indeed meagre, and the word 'computer' has been surrounded with an aura of mysticism which suggests that it is some fantastic piece of electronic gadgetry comprehensible only to a veritable genius. The clinician consequently turns to the only scientific colleague with whom he has direct contact - the medical physicist - and expects him to be an authority. The physicist is thus thrust, however unwillingly, into the forefront of the advance of computer assistance to scientific medicine. It is therefore essential for him to acquire sufficient knowledge of computing science to enable him to provide satisfactory answers for the clinicianst queries, to proffer more detailed advice as to programming convince clinicians that the computer is really a 'simpleton' which can only add and subtract and even that only under instruction.

  5. The last universal physicist

    Energy Technology Data Exchange (ETDEWEB)

    Coccia, Eugenio [Gran Sasso National Laboratory, University of Rome ' Tor Vergata' (Italy)]. E-mail coccia@lngs.infn.it

    2005-04-01

    Born in Rome in 1901, Fermi was the last universal physicist - the most extraordinary of his century. He was at home in the workshop, the laboratory and among theoretical physicists. For the theorists he was a great theorist, and for the experimentalists he was a great experimentalist. What made Fermi so special as a physicist was his universality and versatility; what made him so special as a person was his modesty, realism and frugal lifestyle. This book, which describes Fermi's contributions to physics and the US period of his life, originated from a symposium that was held in Chicago in 2001 to commemorate the centenary of his birth. But it is not merely a volume of reminiscences. It combines essays, specially commissioned articles, as well as private material from Fermi's research notebooks, correspondence and speeches. Together the material highlights the breadth of his impact on physics. A classic biographical introduction by Emilio Segre is followed by an article in which Frank Wilczek, who shared the Nobel Prize for Physics last year, puts into perspective Fermi's huge contributions to physics. The list of his achievements is impressive. They include the introduction of Fermi statistics for half-integer-spin particles (1925) - now called fermions - that led to the concept of the 'Fermi surface' in condensed-matter and nuclear physics; the vector-coupling theory for beta-decay (1933), which formulated the proper structure of the weak interaction where the 'Fermi constant' measures the strength of the coupling; and the introduction, with his Rome group, of neutron-induced radioactivity and the study of slow-neutron interactions (1934). As a researcher and a teacher, Fermi inspired two generations and two continents - a man whose charismatic nature attracted many talented scientists and students to Chicago. What emerges from this book is the gratitude of so many extraordinary physicists to their master, who instilled in them

  6. II-VI semiconductor compounds

    CERN Document Server

    1993-01-01

    For condensed matter physicists and electronic engineers, this volume deals with aspects of II-VI semiconductor compounds. Areas covered include devices and applications of II-VI compounds; Co-based II-IV semi-magnetic semiconductors; and electronic structure of strained II-VI superlattices.

  7. Semiconductor photocatalysis principles and applications

    CERN Document Server

    Kisch, Horst

    2014-01-01

    Focusing on the basic principles of semiconductor photocatalysis, this book also gives a brief introduction to photochemistry, photoelectrochemistry, and homogeneous photocatalysis. In addition, the author - one of the leading authorities in the field - presents important environmental and practical aspects. A valuable, one-stop source for all chemists, material scientists, and physicists working in this area, as well as novice researchers entering semiconductor photocatalysis.

  8. Female physicist doctoral experiences

    Directory of Open Access Journals (Sweden)

    Katherine P. Dabney

    2013-04-01

    Full Text Available The underrepresentation of women in physics doctorate programs and in tenured academic positions indicates a need to evaluate what may influence their career choice and persistence. This qualitative paper examines eleven females in physics doctoral programs and professional science positions in order to provide a more thorough understanding of why and how women make career choices based on aspects both inside and outside of school and their subsequent interaction. Results indicate that female physicists experience conflict in achieving balance within their graduate school experiences and personal lives and that this then influences their view of their future careers and possible career choices. Female physicists report both early and long-term support outside of school by family, and later departmental support, as being essential to their persistence within the field. A greater focus on informal and out-of-school science activities for females, especially those that involve family members, early in life may help influence their entrance into a physics career later in life. Departmental support, through advisers, mentors, peers, and women’s support groups, with a focus on work-life balance can help females to complete graduate school and persist into an academic career.

  9. Female physicist doctoral experiences

    Science.gov (United States)

    Dabney, Katherine P.; Tai, Robert H.

    2013-06-01

    The underrepresentation of women in physics doctorate programs and in tenured academic positions indicates a need to evaluate what may influence their career choice and persistence. This qualitative paper examines eleven females in physics doctoral programs and professional science positions in order to provide a more thorough understanding of why and how women make career choices based on aspects both inside and outside of school and their subsequent interaction. Results indicate that female physicists experience conflict in achieving balance within their graduate school experiences and personal lives and that this then influences their view of their future careers and possible career choices. Female physicists report both early and long-term support outside of school by family, and later departmental support, as being essential to their persistence within the field. A greater focus on informal and out-of-school science activities for females, especially those that involve family members, early in life may help influence their entrance into a physics career later in life. Departmental support, through advisers, mentors, peers, and women’s support groups, with a focus on work-life balance can help females to complete graduate school and persist into an academic career.

  10. Semiconductor Physical Electronics

    CERN Document Server

    Li, Sheng

    2006-01-01

    Semiconductor Physical Electronics, Second Edition, provides comprehensive coverage of fundamental semiconductor physics that is essential to an understanding of the physical and operational principles of a wide variety of semiconductor electronic and optoelectronic devices. This text presents a unified and balanced treatment of the physics, characterization, and applications of semiconductor materials and devices for physicists and material scientists who need further exposure to semiconductor and photonic devices, and for device engineers who need additional background on the underlying physical principles. This updated and revised second edition reflects advances in semicondutor technologies over the past decade, including many new semiconductor devices that have emerged and entered into the marketplace. It is suitable for graduate students in electrical engineering, materials science, physics, and chemical engineering, and as a general reference for processing and device engineers working in the semicondi...

  11. C++ for Particle Physicists

    CERN Multimedia

    Monique Duval

    2002-01-01

    Paul Kunz will be giving his very popular and highly recommended C++ course again on 22-26 July (6 * 3 hour lectures). The course is organised by the CERN Technical Training Programme, it costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page, accessible from the Technical Training pages. Team Visitors should ask their Group Leader to send an e-mail to the DTO of EP Division, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent.

  12. C++ for Particle Physicists

    CERN Multimedia

    2003-01-01

    Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on 10 - 14 March. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page : http://cern.ch/TechnicalTraining/ENSTEC/p2002/Software/cpppp_e.asp Team Visitors should ask their Group Leader to send an e-mail to the DTO of EP Division, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent.

  13. C++ FOR PARTICLE PHYSICISTS

    CERN Multimedia

    Monique Duval

    2002-01-01

    Paul Kunz will be giving his very popular and highly recommended C++ course again on 22-26 July (6 * 3 hour lectures). The course is organised by the CERN Technical Training Programme, it costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page, accessible from the Technical Training pages. Team Visitors should ask their Group Leader to send an e-mail to the DTO of EP Division, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent.

  14. C++ for Particle Physicists

    CERN Multimedia

    Technical Training; Tel. 74924

    2001-01-01

    Paul Kunz will be giving his very popular and highly recommended C++ course again on 8 - 12 October. The course costs 200 CHF, and advance registration is required. Please note that this will be the last session in 2001 and the next one is planned for March 2002. People with CERN EDH accounts can apply electronically directly from the Web course description page : http://www.cern.ch/Training/ENSTEC/P2001/Software/cpppp_e.htm   Team Visitors should ask their Group Leader to send an e-mail to the DTO of EP Division, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent.

  15. C++ FOR PARTICLE PHYSICISTS

    CERN Multimedia

    TECHNICAL TRAINING; Tel. 74460

    2001-01-01

    Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on March 5 to 9. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page : http://www.cern.ch/Training/ENSTEC/P9798/Software/cpppp_e.htm Team Visitors should ask their Group Leader to send an e-mail to the DTO of EP Division, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent.

  16. Caverns for neutrino physicists

    International Nuclear Information System (INIS)

    Duffaut, P.

    2005-01-01

    Since more than 20 years, particle physicists are using underground facilities to catch cosmic neutrinos and to get rid of other parasitic cosmic radiations. The observation of significant numbers of neutrinos requires the use of large volume caverns at important depths. This article presents such existing facilities in the US, France, Italy, UK, Spain, Japan (Kamioka), Russia and India and the different projects in competition for the setting up of a mega-ton detector with a volume of 1 million m 3 of water (DUSEL project in the US, MEMPHYS project in France, Hyperkamiokande in Japan). Several suitable underground spaces are available in these countries (abandoned mines, tunnels) but each has its advantages and drawbacks in terms of rock mechanics, access and seismicity. (J.S.)

  17. Physicists get INSPIREd

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    Particle physicists thrive on information. They first create information by performing experiments or elaborating theoretical conjectures and then they share it through publications and various web tools. The INSPIRE service, just released, will bring state of the art information retrieval to the fingertips of researchers.   Keeping track of the information shared within the particle physics community has long been the task of libraries at the larger labs, such as CERN, DESY, Fermilab and SLAC, as well as the focus of indispensible services like arXiv and those of the Particle Data Group. In 2007, many providers of information in the field came together for a summit at SLAC to see how physics information resources could be enhanced, and the INSPIRE project emerged from that meeting. The vision behind INSPIRE was built by a survey launched by the four labs to evaluate the real needs of the community. INSPIRE responds to these directives from the community by combining the most successful aspe...

  18. C++ for Particle Physicists

    CERN Multimedia

    Monique Duval

    2004-01-01

    Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on 15 �- 19 November. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page: Team Visitors should ask their Group Leader to send an e-mail to the DTO of PH Department, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent. ENSEIGNEMENT TECHNIQUE TECHNICAL TRAINING Monique Duval 74924 technical.training@cern.ch

  19. C++ for Particle Physicists

    CERN Multimedia

    Monique Duval

    2004-01-01

    Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on 15 - 19 November. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page: Team Visitors should ask their Group Leader to send an e-mail to the DTO of PH Department, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent. ENSEIGNEMENT TECHNIQUE TECHNICAL TRAINING Monique Duval 74924 technical.training@cern.ch

  20. Structure Factor of a Hard-core Fluid with Short-range Yukawa Attraction: Analytical FMSA Theory against Monte Carlo Simulations.

    Czech Academy of Sciences Publication Activity Database

    Melnyk, R.; Nezbeda, Ivo; Trokhymchuk, A.

    2016-01-01

    Roč. 114, 16-17 (2016), s. 2523-2529 ISSN 0026-8976 Institutional support: RVO:67985858 Keywords : hard-core fluid * reference system * short-range Yukawa attraction Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.870, year: 2016

  1. What is a medical physicist?

    International Nuclear Information System (INIS)

    Endo, Masahiro

    2011-01-01

    The modern radiotherapy requires a medical physicist who optimizes treatment plans, assures delivered dose equal to prescription, and performs QA (quality assurance) of radiotherapy equipments. However, medical physicist has not been established as a medical profession in Japan mainly because importance of radiotherapy was not sufficiently recognized until recently. Between 2000 and 2004, several accidents of radiotherapy including hundreds of patients were found and these accidents were mainly caused by lack of QA. The necessity and importance of medical physicist were recognized by these accidents as well as by the advent of high-precision radiotherapy such as IMRT (intensity modulation radiation therapy). JRS (Japan Radiological Society) that certified medical physicists with the help of JSMP (Japan Society of Medical Physics), decided to extend eligibility in order to increase certified medical physicists rapidly in 2003. After the decision certified medical physicists were rapidly increased in number. The government supports this tendency to enact that certified medical physicists is necessary to reimbursement for high-precision therapy. It also started to supply grants for medical physics training in physical and health science graduate schools. In this program several universities have started medical physics course in their graduate schools. If these movements continue, medical physicist will be established as a medical profession in the near future. (author)

  2. The health physicist abroad

    International Nuclear Information System (INIS)

    Stewart, N.G.

    1980-01-01

    As health physics research teams at Harwell found adequate solutions to some of the problems in radiological protection and other spheres of nuclear technology, a mixed research programme consisting of both nuclear and non-nuclear research was undertaken by the health physics research teams since 1968 at Harwell with the aim of retaining radiological research experience. This policy widened the scope and interests of the health physicists and subsequently it was observed that particularly in the field of environment and toxicology, the division between nuclear and non-nuclear research is an artificial one. For example, the techniques developed and skills acquired to study the uptake and metabolism of radioactive aerosols were employed to study inhalation toxicology of lead aerosols from motor vehicles and their deposition on the plant and soil surfaces, influence of particle size on deposition and uptake of lead by man and plants. These techniques and skills were redeployed on new radiological problems as they arose, for example, to study the deposition and resuspension of plutonium from land and water surfaces to provide data appropriate to European conditions. Some such more examples from the work of the Environmental and Medical Sciences Division at Harwell are given. (M.G.B.)

  3. ATLAS Physicist in Space

    CERN Multimedia

    Bengt Lund-Jensen

    2007-01-01

    On December 9, the former ATLAS physicist Christer Fuglesang was launched into space onboard the STS-116 Space Shuttle flight from Kennedy Space Center in Florida. Christer worked on the development of the accordion-type liquid argon calorimeter and SUSY simulations in what eventually became ATLAS until summer 1992 when he became one out of six astronaut trainees with the European Space Agency (ESA). His selection out of a very large number of applicants from all over the ESA member states involved a number of tests in order to choose the most suitable candidates. As ESA astronaut Christer trained with the Russian Soyuz programme in Star City outside of Moscow from 1993 until 1996, when he moved to Houston to train for space shuttle missions with NASA. Christer belonged to the backup crew for the Euromir95 mission. After additional training in Russia, Christer qualified as ‘Soyuz return commander’ in 1998. Christer rerouting cables during his second space walk. (Photo: courtesy NASA) During...

  4. Summertime for physicists

    CERN Multimedia

    2013-01-01

    Summer for particle physicists is the season for “summer conferences” and the past week saw two big meetings in full swing. The 2013 European Physical Society High-Energy Physics (EPS-HEP) conference took place in Stockholm, Sweden, while the Strangeness in Quark Matter conference visited Birmingham in the UK for its 2013 edition.   Such conferences usually mark the culmination of months of hard work to prepare new results and, if nature is kind, they also provide the stage for the announcement of discoveries. But more than that, they allow people to network with colleagues from far and wide. I was at EPS-HEP, which belies its name and, like particle physics itself, has a global reach, with people attending from Asia and the Americas. This year there were some 750 attendees, including many young people. The programme of parallel sessions allowed many of them to present results they had worked on in what can be huge collaborations. It’s impressive to see their eff...

  5. Study of a model Fermi liquid interacting via a hard-core repulsive potential and an attractive tail

    International Nuclear Information System (INIS)

    Ng, Tai Kai; Singwi, K.S.

    1986-02-01

    In this paper we present an extensive microscopic study of the collective and single-particle properties of a model Fermi liquid whose particles interact via a repulsive hard-core potential and an attractive tail. The model system is intended to simulate liquid 3 He. The study is based on an approximate scheme of Singwi, Tosi, Land and Sjoelander (STLS) which was devised to treat correlations in Coulomb Fermi liquids. The primary aim of this study is to learn whether the model system is capable of reproducing some of the salient features observed in normal liquid 3 He, and about the role of the repulsive and attractive parts of the potential. We have calculated the Landau parameters F 0 /sup s/ and F 0 /sup a/ and their variation with pressure, the wave number and pressure dependence of the spin-symmetric and spin-anti-symmetric polarization potentials, pressure dependence of the dispersion of the zero sound, the static structure factors and the quasiparticle mass. Although we make no quantitative claims when comparing our calculations with experiments in real liquid 3 He, we do conclude that our model system within the framework of the STLS scheme can account qualitatively for the latter. Besides, since the theory is microscopic in nature and is parameter free, it has enabled us to understand better the role of the repulsive and the attractive parts of the bare potential in determining the properties of liquid 3 He. 27 figs., 2 tabs

  6. Stability analysis and numerical simulation of a hard-core diffuse z pinch during compression with Atlas facility liner parameters

    Science.gov (United States)

    Siemon, R. E.; Atchison, W. L.; Awe, T.; Bauer, B. S.; Buyko, A. M.; Chernyshev, V. K.; Cowan, T. E.; Degnan, J. H.; Faehl, R. J.; Fuelling, S.; Garanin, S. F.; Goodrich, T.; Ivanovsky, A. V.; Lindemuth, I. R.; Makhin, V.; Mokhov, V. N.; Reinovsky, R. E.; Ryutov, D. D.; Scudder, D. W.; Taylor, T.; Yakubov, V. B.

    2005-09-01

    In the 'metal liner' approach to magnetized target fusion (MTF), a preheated magnetized plasma target is compressed to thermonuclear temperature and high density by externally driving the implosion of a flux conserving metal enclosure, or liner, which contains the plasma target. As in inertial confinement fusion, the principal fusion fuel heating mechanism is pdV work by the imploding enclosure, called a pusher in ICF. One possible MTF target, the hard-core diffuse z pinch, has been studied in MAGO experiments at VNIIEF and is one possible target being considered for experiments on the Atlas pulsed power facility. Numerical MHD simulations show two intriguing and helpful features of the diffuse z pinch with respect to compressional heating. First, in two-dimensional simulations the m = 0 interchange modes, arising from an unstable pressure profile, result in turbulent motions and self-organization into a stable pressure profile. The turbulence also gives rise to convective thermal transport, but the level of turbulence saturates at a finite level, and simulations show substantial heating during liner compression despite the turbulence. The second helpful feature is that pressure profile evolution during compression tends towards improved stability rather than instability when analysed according to the Kadomtsev criteria. A liner experiment is planned for Atlas to study compression of magnetic flux without plasma, as a first step. The Atlas geometry is compatible with a diffuse z pinch, and simulations of possible future experiments show that kiloelectronvolt temperatures and useful neutron production for diagnostic purposes should be possible if a suitable plasma injector is added to the Atlas facility.

  7. Diffusion of finite-sized hard-core interacting particles in a one-dimensional box: Tagged particle dynamics.

    Science.gov (United States)

    Lizana, L; Ambjörnsson, T

    2009-11-01

    We solve a nonequilibrium statistical-mechanics problem exactly, namely, the single-file dynamics of N hard-core interacting particles (the particles cannot pass each other) of size Delta diffusing in a one-dimensional system of finite length L with reflecting boundaries at the ends. We obtain an exact expression for the conditional probability density function rhoT(yT,t|yT,0) that a tagged particle T (T=1,...,N) is at position yT at time t given that it at time t=0 was at position yT,0. Using a Bethe ansatz we obtain the N -particle probability density function and, by integrating out the coordinates (and averaging over initial positions) of all particles but particle T , we arrive at an exact expression for rhoT(yT,t|yT,0) in terms of Jacobi polynomials or hypergeometric functions. Going beyond previous studies, we consider the asymptotic limit of large N , maintaining L finite, using a nonstandard asymptotic technique. We derive an exact expression for rhoT(yT,t|yT,0) for a tagged particle located roughly in the middle of the system, from which we find that there are three time regimes of interest for finite-sized systems: (A) for times much smaller than the collision time tparticle concentration and D is the diffusion constant for each particle, the tagged particle undergoes a normal diffusion; (B) for times much larger than the collision time t >taucoll but times smaller than the equilibrium time ttaue , rhoT(yT,t|yT,0) approaches a polynomial-type equilibrium probability density function. Notably, only regimes (A) and (B) are found in the previously considered infinite systems.

  8. Are physicists' philosophies irrelevant idiosyncrasies?

    NARCIS (Netherlands)

    de Regt, H.W.|info:eu-repo/dai/nl/112827802

    1996-01-01

    This article argues that individual philosophical commitments of scientists can decisively influence scientific practice. To support this claim, two historical examples are presented, concerning controversies between physicists about central problems in their field. Confrontation of the theories of

  9. Japanese physicist during the war

    International Nuclear Information System (INIS)

    Brown, L.; Nambu, Y.

    1999-01-01

    The japanese interest for the science is comparatively recent and one of the first japanese physicist is Hantoro Nagaoka with an atomic model in 1903. During the war the physicist take refuge in the theory and two universities proper in spite of difficult working conditions. This paper goes over the historical aspects of the japanese scientific research and contributions to the nucleus physic. (A.L.B.)

  10. Topology and geometry for physicists

    CERN Document Server

    Nash, Charles

    1983-01-01

    Differential geometry and topology are essential tools for many theoretical physicists, particularly in the study of condensed matter physics, gravity, and particle physics. Written by physicists for physics students, this text introduces geometrical and topological methods in theoretical physics and applied mathematics. It assumes no detailed background in topology or geometry, and it emphasizes physical motivations, enabling students to apply the techniques to their physics formulas and research. ""Thoroughly recommended"" by The Physics Bulletin, this volume's physics applications range fr

  11. Advances in semiconductor lasers

    CERN Document Server

    Coleman, James J; Jagadish, Chennupati

    2012-01-01

    Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. Originally widely known as the ""Willardson and Beer"" Series, it has succeeded in publishing numerous landmark volumes and chapters. The series publishes timely, highly relevant volumes intended for long-term impact and reflecting the truly interdisciplinary nature of the field. The volumes in Semiconductors and Semimetals have been and will continue to be of great interest to physicists, chemists, materials scientists, and device engineers in academia, scien

  12. Perspective for Female Medical Physicists

    International Nuclear Information System (INIS)

    Naqvi, Syed Mansoor; Hasnain, Aziz Fatima

    2009-01-01

    Due to cultural and religious reasons, Pakistani women can be reluctant to seek medical attention for disorders affecting their genitals or breasts. As a result, in the case of cervical and breast cancers, oncological treatment is often not received until the diseases are in the late stages. Once a cancer is classified and the tumor marked, the role of the medical physicist begins. Medical physicists' responsibilities include treatment planning, supervising treatment through radiation, dosimetry, contouring, training, equipment selection, education, research, and supervising radiotherapy facilities. In brachytherapy, isotopes are placed at the tumor site in the form of wires or seeds. There are very few female medical physicists in Pakistan. This leads to further hesitation on the part of many women to seek treatment. To help female patients obtain needed medical care, female physics students should be encouraged to pursue the emerging field of medical physics. This would provide a new professional opportunity for female physics students and give comfort to female patients.

  13. neutron-Induced Failures in semiconductor Devices

    Energy Technology Data Exchange (ETDEWEB)

    Wender, Stephen Arthur [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-13

    Single Event Effects are a very significant failure mode in modern semiconductor devices that may limit their reliability. Accelerated testing is important for semiconductor industry. Considerable more work is needed in this field to mitigate the problem. Mitigation of this problem will probably come from Physicists and Electrical Engineers working together

  14. Complementary Colours for a Physicist

    Science.gov (United States)

    Babic, Vitomir; Cepic, Mojca

    2009-01-01

    This paper reports on a simple experiment which enables splitting incident light into two different modes, each having a colour exactly complementary to the other. A brief historical development of colour theories and differences in a physicist's point of view with respect to an artist's one is discussed. An experimental system for producing…

  15. Nuclear physicist, arms control advocate

    CERN Multimedia

    Chang, K

    2002-01-01

    Victor F. Weisskopf, a nuclear physicist who worked on the Manhattan Project to build the first atomic bomb in World War II and later became an ardent advocate of arms control, died Monday at his home in Newton, MA, USA. He was 93 (1 page).

  16. LHC Olympics flex physicists' brains

    CERN Multimedia

    2006-01-01

    Physicists from around the world met at CERN to strengthen their data-deciphering skills at the second LHC Olympics workshop. Physicists gather for the second LHC Olympics workshop. Coinciding with the kick-off of the winter Olympics in Turin, more than 70 physicists gathered at CERN from across the globe for the second LHC Olympics workshop on 9-10 February. Their challenge, however, involved brains rather than brawn. As the switch-on date for the LHC draws near, scientists excited by the project want to test and improve their ability to decipher the unprecedented amount of data that the world's biggest and most powerful particle accelerator is expected to generate. The LHC Olympics is a coordinated effort to do just that, minus the gold, silver and bronze of the athletics competition. 'In some ways, the LHC is not a precision instrument. It gives you the information that something is there but it's hard to untangle and interpret what it is,' said University of Michigan physicist Gordy Kane, who organiz...

  17. A Physicist Looks at Biology

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 4; Issue 11. A Physicist Looks at Biology. Max Delbrück. Classics Volume 4 Issue 11 November 1999 pp 89-102. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/004/11/0089-0102. Author Affiliations.

  18. Mathematics for Physicists and Engineers.

    Science.gov (United States)

    Organisation for Economic Cooperation and Development, Paris (France).

    The text is a report of the OEEC Seminar on "The Mathematical Knowledge Required by the Physicist and Engineer" held in Paris, 1961. There are twelve major papers presented: (1) An American Parallel (describes the work of the Panel on Physical Sciences and Engineering of the Committee on the Undergraduate Program in Mathematics of the Mathematical…

  19. Phase transitions in the hard-core Bose-Fermi-Hubbard model at non-zero temperatures in the heavy-fermion limit

    Energy Technology Data Exchange (ETDEWEB)

    Stasyuk, I.V.; Krasnov, V.O., E-mail: krasnoff@icmp.lviv.ua

    2017-04-15

    Phase transitions at non-zero temperatures in ultracold Bose- and Fermi-particles mixture in optical lattices using the Bose-Fermi-Hubbard model in the mean field and hard-core boson approximations are investigated. The case of infinitely small fermion transfer and the repulsive on-site boson-fermion interaction is considered. The possibility of change of order (from the 2nd to the 1st one) of the phase transition to the superfluid phase in the regime of fixed values of the chemical potentials of Bose- and Fermi-particles is established. The relevant phase diagrams determining the conditions at which such a change takes place, are built.

  20. Fractional derivatives for physicists and engineers background and theory

    CERN Document Server

    Uchaikin, Vladimir V

    2013-01-01

    The first derivative of a particle coordinate means its velocity, the second means its acceleration, but what does a fractional order derivative mean? Where does it come from, how does it work, where does it lead to? The two-volume book written on high didactic level answers these questions. Fractional Derivatives for Physicists and Engineers— The first volume contains a clear introduction into such a modern branch of analysis as the fractional calculus. The second develops a wide panorama of applications of the fractional calculus to various physical problems. This book recovers new perspectives in front of the reader dealing with turbulence and semiconductors, plasma and thermodynamics, mechanics and quantum optics, nanophysics and astrophysics.  The book is addressed to students, engineers and physicists, specialists in theory of probability and statistics, in mathematical modeling and numerical simulations, to everybody who doesn't wish to stay apart from the new mathematical methods becoming more and ...

  1. Physicists' Forced Migrations under Hitler

    Science.gov (United States)

    Beyerchen, Alan

    2011-03-01

    When the Nazis came to power in early 1933 they initiated formal and informal measures that forced Jews and political opponents from public institutions such as universities. Some physicists retired and others went into industry, but most emigrated. International communication and contact made emigration a viable option despite the desperate economic times in the Great Depression. Another wave of emigrations followed the annexation of Austria in 1938. Individual cases as well as general patterns of migration and adaptation to new environments will be examined in this presentation. One important result of the forced migrations was that many of the physicists expelled under Hitler played important roles in strengthening physics elsewhere, often on the Allied side in World War II.

  2. Clinically related anatomy for physicists

    International Nuclear Information System (INIS)

    Wright, A.E.; Boyer, A.L.

    1987-01-01

    With the advent of CT and MR imaging, delineation of malignancies and the shaping of radiation treatment fields have become much more precise. Treatment planning in more than one transverse plane is more widely practiced as the use of sophisticated computers grow. These developments emphasize the need for the physicist to have a basic knowledge of human anatomy. This course is designed to familiarize the clinical physicist with the gross anatomy and topographic landmarks used by the physician in planning three-dimensional radiation treatment volumes. The significance of the various anatomic structures and their related lymphatics in the spread of disease is discussed. Emphasis is placed on disease entities that pose particular problems due to overlying or nearby healthy structures at risk

  3. EPS Young Physicist Prize - CORRECTION

    CERN Multimedia

    2009-01-01

    The original text for the article 'Prizes aplenty in Krakow' in Bulletin 30-31 assigned the award of the EPS HEPP Young Physicist Prize to Maurizio Pierini. In fact he shared the prize with Niki Saoulidou of Fermilab, who was rewarded for her contribution to neutrino physics, as the article now correctly indicates. We apologise for not having named Niki Saoulidou in the original article.

  4. Physicist makes muon chamber sing

    CERN Multimedia

    2007-01-01

    This Monitored Drift Tube detector, consisting of argon-CO2-filled aluminium tubes with a wire down the centre of each, will track muons in ATLAS; Tiecke used a single tube from one of these detectors to create the pipes in his organ. Particle physicists can make good musicians; but did you know particle detectors can make good music? That's what NIKHEF physicist Henk Tiecke learned when he used pipes cut from the ATLAS Monitored Drift Tube detector (MDT) to build his own working Dutch-style barrel organ in the autumn of 2005. 'I like to work with my hands,' said Tiecke, who worked as a senior physicist at NIKHEF, Amsterdam, on ZEUS until his retirement last summer. Tiecke had already constructed his barrel organ when he visited some colleagues in the ATLAS muon chambers production area at Nikhef in 2005. He noticed that the aluminium tubes they were using to build the chambers were about three centimetres in diameter-just the right size for a pipe in a barrel organ. 'The sound is not as nice as from wooden...

  5. My recollections as a physicist

    Energy Technology Data Exchange (ETDEWEB)

    Tsai, Yung-su

    1997-03-01

    This presentation is a talk presented by the author at a Physics Symposium of the 50th anniversary of the Taiwan University, in December 1996. The author describes how he became a physicist, and then presents a brief outline of his professional career, most of which has centered at Stanford Linear Accelerator Center. He was involved in the discovery of the {tau} lepton, and in studies of CP violation through decay of the {tau}, in addition to studies of semileptonic decay of t, B, D, K, and {pi}.

  6. Murdered physicist leaves Iran reeling

    Science.gov (United States)

    Dacey, James

    2010-02-01

    The murder of the Iranian physicist Masoud Alimohammadi last month has left the country's academic community in a state of shock. Alimohammadi, a 50-year-old physics professor at the University of Tehran, was killed on 12 January by a remote-controlled bomb attached to the side of a motorcycle outside his home. The bomb was detonated as he left for work, but the reason for the murder remained unclear as Physics World went to press. Reports by the Iranian state media blamed the US and Israel for the attack - a claim that the US later described as "absurd".

  7. An Applied Physicist Does Econometrics

    Science.gov (United States)

    Taff, L. G.

    2010-02-01

    The biggest problem those attempting to understand econometric data, via modeling, have is that economics has no F = ma. Without a theoretical underpinning, econometricians have no way to build a good model to fit observations to. Physicists do, and when F = ma failed, we knew it. Still desiring to comprehend econometric data, applied economists turn to mis-applying probability theory---especially with regard to the assumptions concerning random errors---and choosing extremely simplistic analytical formulations of inter-relationships. This introduces model bias to an unknown degree. An applied physicist, used to having to match observations to a numerical or analytical model with a firm theoretical basis, modify the model, re-perform the analysis, and then know why, and when, to delete ``outliers'', is at a considerable advantage when quantitatively analyzing econometric data. I treat two cases. One is to determine the household density distribution of total assets, annual income, age, level of education, race, and marital status. Each of these ``independent'' variables is highly correlated with every other but only current annual income and level of education follow a linear relationship. The other is to discover the functional dependence of total assets on the distribution of assets: total assets has an amazingly tight power law dependence on a quadratic function of portfolio composition. Who knew? )

  8. ["The hard core". Science between politics and philosophy by Carl Friedrich von Weizsäcker and in the finalization theory].

    Science.gov (United States)

    Krohn, Wolfgang

    2014-01-01

    In the Starnberg Max-Planck Institute one of the working groups was concerned with science as the formative condition--or "hard core"--of societal modernity, and with science as potential resource for solving social problems and addressing future goals. More precisely, the group intended to differentiate between phases in which scientific disciplines predominantly care for their own paradigmatic completion and those allowing their theoretical potential resonate with external needs. The conceptual model was coined "finalization in science". It soon provoked a heated controversy on the dangers of social control of science. The paper analyses Carl Friedrich von Weizsäcker's views on the relation between philosophy and policy of science including his interpretation of Thomas Kuhn and reconstructs the impact of his ideas on the finalization model. It finally reflects on the relationship between science development and change of consciousness in the context of scientific responsibility for (the use of) research outcomes.

  9. The Needs of Male Visuality: The Rhetoric of Male Gaze in Snuff and Hard-Core Culture between Cinema and Literature

    Directory of Open Access Journals (Sweden)

    Mirko Lino

    2014-06-01

    -  Social and cultural: the need of having to re-establish male dominance against the destructuring action of feminism. The field of analysis of cinematographic and literary outputs is focused on two titles: Snuff (1976 a movie produced by A. Shackleton, and the novel Snuff (2008 by Chuck Palahniuk. The movie is useful for the description of a snuff aesthetic and the rhetoric of male gaze; the novel instead is useful for the identification of relevant features about gender questions applied to extreme hard core pornography. At the end, it will be demonstrated the political attempt to reverse the hegemonic rhetoric of male gaze acting directly on the aesthetic of snuff movie ritual.

  10. Os dois métodos e o núcleo duro da teoria econômica The two methods and the hard core of economics

    Directory of Open Access Journals (Sweden)

    Luiz Carlos Bresser-Pereira

    2009-06-01

    Full Text Available While methodological sciences have no object and are supposed to adopt a hypothetical-deductive method, substantive sciences including economics should use an empirical or historical-deductive method. The great classical economists and Keynes did that and were able to develop open models explaining how equally open economic systems work. Thus, the hard core of relevant economics is formed by the classical microeconomics and the classical theory of capitalist economic growth, and by Keynesian macroeconomics. In contrast, neoclassical economist aiming to build a mathematical science wrongly adopted the hypothetical-deductive method, and came to macroeconomic and growth models that do not have practical use in policymaking. The exception is Marshall's microeconomics that does not provide a model of real economic systems, but is useful to the analysis of markets.

  11. Britain honours its particle physicists

    CERN Multimedia

    2004-01-01

    Theoretical and experimental particle physicists figure among the winners for 2004 of Britain's most prestigious prizes for physics, awarded by the Institute of Physics (IOP). The IOP's own Paul Dirac medal and prize, goes to this year to CERN's John Ellis for "his highly influential work on particle-physics phenomenology; in particular on the properties of gluons, the Higgs boson and the top quark". One of the institute's premier wards, it is made for outstanding contributions to theoretical (including mathematical and computational) physics. The Duddell medal and prize, in memory of William du Bois Duddell, the inventor of the electromagnetic oscillograph, is awarded for outstanding contributions to the advancement of knowledge through the application of physics, including the invention or design of scientific instruments or the discovery of materials used in their construction. It is shared this year by Geoff Hall, of Imperial College London, Alessandro Marchioro from CERN and Peter Sharp of the Rutherfor...

  12. Tales of physicists and mathematicians

    CERN Document Server

    Gindikin, Semyon Grigorevich

    1988-01-01

    This revised and greatly expanded second edition of the classic Russian text Tales of Mathematicians and Physicists contains a wealth of new information about the lives and accomplishments of more than a dozen scientists throughout history. Included are individuals from the late nineteenth century: Klein, Poincaré, Ramanujan, and Penrose, as well as renowned figures from earlier eras, such as Leibniz, Euler, Lagrange, and Laplace. A unique mixture of mathematics, physics, and history, this volume provides biographical glimpses of scientists and their contributions in the context of the social and political background of their times. The author examines many original sources, from the scientists’ research papers to their personal documents and letters to friends and family; furthermore, detailed mathematical arguments and diagrams are supplied to help explain some of the most significant discoveries in calculus, celestial mechanics, number theory, and modern relativity. What emerges are intriguing, multifac...

  13. Radiation physics for medical physicists

    CERN Document Server

    Podgorsak, Ervin B

    2006-01-01

    This book summarizes the radiation physics knowledge that professionals working in medical physics need to master for efficient and safe dealings with ionizing radiation. It contains eight chapters, each chapter covering a specific group of subjects related to radiation physics and is intended as a textbook for a course in radiation physics in medical-physics graduate programs. However, the book may also be of interest to the large number of professionals, not only medical physicists, who in their daily occupations deal with various aspects of medical physics and find a need to improve their understanding of radiation physics. The main target audience for this book is graduate students studying for M.Sc. and Ph.D. degrees in medical physics, who have to possess the necessary physics and mathematics background knowledge to be able to follow and master the complete textbook. Medical residents, technology students and biomedical engineering students may find certain sections too challenging or esoteric, yet they...

  14. CERN physicist receives Einstein Medal

    CERN Multimedia

    2006-01-01

    On 29 June the CERN theorist Gabriele Veneziano was awarded the prestigious Albert Einstein Medal for significant contributions to the understanding of string theory. This award is given by the Albert Einstein Society in Bern to individuals whose scientific contributions relate to the work of Einstein. Former recipients include exceptional physicists such as Murray Gell-Mann last year, but also Stephen Hawking and Victor Weisskopf. Gabriele Veneziano, a member of the integrated CERN Theory Team since 1977, led the Theory Division from 1994 to 1997 and has already received many prestigious prizes for his outstanding work, including the Enrico Fermi Prize (see CERN Courier, November 2005), the Dannie Heineman Prize for mathematical physics of the American Physical Society in 2004 (see Bulletin No. 47/2003), and the I. Ya. Pomeranchuk Prize of the Institute of Theoretical and Experimental Physics (Moscow) in 1999.

  15. Physicist pins hopes on particle collider

    CERN Multimedia

    2007-01-01

    Physicist pins hopes on particle collider By Deseret Morning News Published: Monday, Dec. 31, 27 12:4 a.m. MST FONT Scott Thomas, a 187 State University graduate, is working at the frontiers of science. The theoretical physicist is crafting ways to extract fundamental secrets that seem certain to be uncovered by the Large Hadron Collider.

  16. Marie Curie: Physicist and Woman

    Science.gov (United States)

    Howes, Ruth

    Marie Sklodowska was born in Warsaw on November 7, 1867. Girls were not allowed to attend college in Poland, so Marie found a well-paying post as a governess in rural village which she held for three years while helping her older sister complete medical school in Paris. Then Marie moved to Paris and graduated first in her class at the Sorbonne with a master's degree in physics in 1893. In 1895, she married the talented young physicist, Pierre Curie. Marie decided to investigate the radioactive components of the mineral pitchblende for her dissertation. The work involved chemical analysis of a ton of material in an unheated shed. Pierre joined her and at the end of 1898, the Curies announced the discovery of radium and polonium. Through 1899, Marie labored to measure the atomic weight of radium. In 1903, Marie earned her doctorate, the first for a woman in France, and the Curies split the Nobel Prize in Physics with Henri Becquerel. They became widely known, besieged by the press and frequently invited to make presentations and be awarded honors. They hated fame and both suffered bad health. In April, 1906, Pierre Curie was struck by a wagon and killed instantly. Marie was left as a single mother with two young daughters. Fortunately, the Sorbonne hired her to fill Pierre's position. In 1911, she was rejected for membership in the French Academy of Science because she was a woman. Also in 1911, she was accused of having an affair with a married French physicist Paul Langevin. The resulting scandal hit the press and brought angry mobs to her home. In the middle of this hullaballoo, she was informed that she had won a second Nobel Prize, this time in Chemistry. When World War I broke out, Marie mounted x-ray units on cars and became a heroine. She visited the United States in 1921 where President Harding presented her with a gram of radium. She continued her scientific studies in spite of declining health until her death in 1934. Professor Emerita.

  17. Synthesis of the IRSN report.no. 2012-009 on the definition of a post-Fukushima hard core for EDF's PWRs: objectives, content and associated requirements. Opinion related to the post-Fukushima hard core of EDF's pressurized water reactors under construction or in operation

    International Nuclear Information System (INIS)

    2012-12-01

    After having recalled the implementation of the additional safety assessments (ECS) on the French nuclear reactors after the Fukushima accident, and that, after these assessments, ASN asked EDF to implement a 'hard core of robust material and organisational measures' which aim at preventing an accident with a core fusion or at limiting its progress, at limiting massive radioactive releases, and at enabling the operator to perform his required missions in crisis management, a first report briefly indicates the objectives of this hard core, and discuses the material measures proposed by EDF. These measures concern the exploited reactors and the EPR Flamanville 3, the pools present in the fuel and reactor buildings. It also discusses requirements associated with these material measures, notably with respect to earthquake, flooding or other extreme events. It briefly discusses organisational measures. A second report, produced by the Permanent Group of Experts, states the opinion of this group on the same issues, and proposes a set of recommendations for further measures by EDF

  18. Radiation physics for medical physicists

    International Nuclear Information System (INIS)

    Podgorsak, E.B.

    2006-01-01

    This book summarizes the radiation physics knowledge that professionals working in medical physics need to master for efficient and safe dealings with ionizing radiation. It contains eight chapters, each chapter covering a specific group of subjects related to radiation physics and is intended as a textbook for a course in radiation physics in medical-physics graduate programs. However, the book may also be of interest to the large number of professionals, not only medical physicists, who in their daily occupations deal with various aspects of medical physics and find a need to improve their understanding of radiation physics. The main target audience for this book is graduate students studying for M.Sc. and Ph.D. degrees in medical physics, who have to possess the necessary physics and mathematics background knowledge to be able to follow and master the complete textbook. Medical residents, technology students and biomedical engineering students may find certain sections too challenging or esoteric, yet they will find many sections interesting and useful in their studies. Candidates preparing for professional certification exams in any of the medical physics subspecialties should find the material useful, and some of the material would also help candidates preparing for certification examinations in medical dosimetry or radiation-related medical specialties. Numerous textbooks are available covering the various subspecialties of medical physics but they generally make a transition from the elementary basic physics directly into the intricacies of the given medical physics subspecialty. The intent of this textbook is to provide the missing link between the elementary physics on the one hand and the physics of the subspecialties on the other hand. (orig.)

  19. Interfacial effect on physical properties of composite media: Interfacial volume fraction with non-spherical hard-core-soft-shell-structured particles.

    Science.gov (United States)

    Xu, Wenxiang; Duan, Qinglin; Ma, Huaifa; Chen, Wen; Chen, Huisu

    2015-11-02

    Interfaces are known to be crucial in a variety of fields and the interfacial volume fraction dramatically affects physical properties of composite media. However, it is an open problem with great significance how to determine the interfacial property in composite media with inclusions of complex geometry. By the stereological theory and the nearest-surface distribution functions, we first propose a theoretical framework to symmetrically present the interfacial volume fraction. In order to verify the interesting generalization, we simulate three-phase composite media by employing hard-core-soft-shell structures composed of hard mono-/polydisperse non-spherical particles, soft interfaces, and matrix. We numerically derive the interfacial volume fraction by a Monte Carlo integration scheme. With the theoretical and numerical results, we find that the interfacial volume fraction is strongly dependent on the so-called geometric size factor and sphericity characterizing the geometric shape in spite of anisotropic particle types. As a significant interfacial property, the present theoretical contribution can be further drawn into predicting the effective transport properties of composite materials.

  20. Developing Technology Products - A Physicist's Perspective

    Science.gov (United States)

    Burka, Michael

    2014-03-01

    There are many physicists working in the industrial sector. We rarely have the word physicist in our job title; we are far more commonly called engineers or scientists. But, we are physicists, and we succeed because our training in physics has given us the habits of mind and the technical skills that one needs to solve complex technical challenges. This talk will explore the transition from physics research to technology product development using examples from my own career, first as a postdoctoral fellow and research scientist on the LIGO project, and then developing products in the spectroscopy, telecommunications, and medical device industries. Approaches to identifying and pursuing opportunities in industry will be discussed.

  1. Semiconductor statistics

    CERN Document Server

    Blakemore, J S

    1987-01-01

    In-depth exploration of the implications of carrier populations and Fermi energies examines distribution of electrons in energy bands and impurity levels of semiconductors. Also: kinetics of semiconductors containing excess carriers, particularly in terms of trapping, excitation, and recombination.

  2. Semiconductor physics

    CERN Document Server

    Böer, Karl W

    2018-01-01

    This handbook gives a complete survey of the important topics and results in semiconductor physics. It addresses every fundamental principle and most research topics and areas of application in the field of semiconductor physics. Comprehensive information is provided on crystalline bulk and low-dimensional as well as amporphous semiconductors, including optical, transport, and dynamic properties.

  3. Physicists observe subatomic quick-change artist

    CERN Multimedia

    Halber, Deborah

    2006-01-01

    Physicists have announced the observation of a subatomic particle known as the Bs (pronounced "B sub s") meson switching between matter and antimatter states at a mind-boggling 3 trillion times per second (1 page)

  4. More Sci- than Fi, Physicists Create Antimatter

    CERN Multimedia

    Overbye, Dennis

    2002-01-01

    Physicists working in Europe announced yesterday that they had passed through nature's looking glass and had created atoms made of antimatter, or antiatoms, opening up the possibility of experiments in a realm once reserved for science fiction writers (5 pages)

  5. Physicist swaps protons for profit strategies

    CERN Document Server

    Starck, Peter

    2006-01-01

    "A german particle physicist has decided to try his hand as a hedge fund manager and is confident that his award-winning algorithm will mean he hits his return target within weeks of launch." (1/2 page)

  6. Study of long-range orders of hard-core bosons coupled to cooperative normal modes in two-dimensional lattices

    Science.gov (United States)

    Ghosh, A.; Yarlagadda, S.

    2017-09-01

    Understanding the microscopic mechanism of coexisting long-range orders (such as lattice supersolidity) in strongly correlated systems is a subject of immense interest. We study the possible manifestations of long-range orders, including lattice-supersolid phases with differently broken symmetry, in a two-dimensional square lattice system of hard-core bosons (HCBs) coupled to archetypal cooperative/coherent normal-mode distortions such as those in perovskites. At strong HCB-phonon coupling, using a duality transformation to map the strong-coupling problem to a weak-coupling one, we obtain an effective Hamiltonian involving nearest-neighbor, next-nearest-neighbor, and next-to-next-nearest-neighbor hoppings and repulsions. Using stochastic series expansion quantum Monte Carlo, we construct the phase diagram of the system. As coupling strength is increased, we find that the system undergoes a first-order quantum phase transition from a superfluid to a checkerboard solid at half-filling and from a superfluid to a diagonal striped solid [with crystalline ordering wave vector Q ⃗=(2 π /3 ,2 π /3 ) or (2 π /3 ,4 π /3 )] at one-third filling without showing any evidence of supersolidity. On tuning the system away from these commensurate fillings, checkerboard supersolid is generated near half-filling whereas a rare diagonal striped supersolid is realized near one-third filling. Interestingly, there is an asymmetry in the extent of supersolidity about one-third filling. Within our framework, we also provide an explanation for the observed checkerboard and stripe formations in La2 -xSrxNiO4 at x =1 /2 and x =1 /3 .

  7. Research on an uplink carrier sense multiple access algorithm of large indoor visible light communication networks based on an optical hard core point process.

    Science.gov (United States)

    Nan, Zhufen; Chi, Xuefen

    2016-12-20

    The IEEE 802.15.7 protocol suggests that it could coordinate the channel access process based on the competitive method of carrier sensing. However, the directionality of light and randomness of diffuse reflection would give rise to a serious imperfect carrier sense (ICS) problem [e.g., hidden node (HN) problem and exposed node (EN) problem], which brings great challenges in realizing the optical carrier sense multiple access (CSMA) mechanism. In this paper, the carrier sense process implemented by diffuse reflection light is modeled as the choice of independent sets. We establish an ICS model with the presence of ENs and HNs for the multi-point to multi-point visible light communication (VLC) uplink communications system. Considering the severe optical ICS problem, an optical hard core point process (OHCPP) is developed, which characterizes the optical CSMA for the indoor VLC uplink communications system. Due to the limited coverage of the transmitted optical signal, in our OHCPP, the ENs within the transmitters' carrier sense region could be retained provided that they could not corrupt the ongoing communications. Moreover, because of the directionality of both light emitting diode (LED) transmitters and receivers, theoretical analysis of the HN problem becomes difficult. In this paper, we derive the closed-form expression for approximating the outage probability and transmission capacity of VLC networks with the presence of HNs and ENs. Simulation results validate the analysis and also show the existence of an optimal physical carrier-sensing threshold that maximizes the transmission capacity for a given emission angle of LED.

  8. Meeting "real" physicists in the flesh

    CERN Multimedia

    CERN Bulletin

    2010-01-01

    CERN physicists don't wear white coats (at least not very often); they don't all wear glasses and they don't concoct dangerous potions. They are often even women. These are some of the discoveries made by children from local schools taking part in the "Draw me a physicist" project. Franck Martin, an ATLAS physicist, answers questions from children from the Satigny-Village school.   20 school-classes from the Swiss communes of Meyrin, Satigny and Vernier and from the Pays de Gex in France have been taking part in this project, which involved the children making an initial drawing and writing a "dictionary-style" definition of a physicist in their classrooms, and then visiting CERN during the week of March 15th. The Swiss children were also treated to a show put on by the Physicscope group. During their visit to CERN they were able to see the laboratories and experiments for real and get an idea of what a physicist's job involves by interviewing a real male and...

  9. Particle physicists want to expand open access

    CERN Multimedia

    Kaiser, Jocelyn

    2006-01-01

    "Particle physicists have come up with a novel way to promote free, immediate access to journal articles. Led by CERN, the gian lab near Geneva, Switzerland, they want to raise at least $6 million a year to begin buying open access to all published papers in their field." (1 page)

  10. Physicists tackles questions of tiny dimensions

    CERN Multimedia

    Moran, Barbara

    2003-01-01

    Today's physicists have a dilemna: they are using two separate theories to describe the universe. General relativity, which describes gravity, works for large objects like planets. Quantum mechanics, which involves the other forces, works for tiny objects like atoms. Unfortunately, the two theories don't match up.

  11. Particle physicists join battle against cancer

    CERN Multimedia

    Cartlidge, Edwin

    2005-01-01

    Technologies originally developed for experiments in particle physcis are being used to diagnose and treat cancer. About 130 physicists and healthcare proessionals met in London recently to discuss "The future of medical imaging and radiotherapy"; a major theme at the meeting was how technology from particle physics could be used to diagnose and treat cancer (1/2 page)

  12. Introductory fluid mechanics for physicists and mathematicians

    CERN Document Server

    Pert, Geoffrey J

    2013-01-01

    This textbook presents essential methodology for physicists of the theory and applications of fluid mechanics within a single volume.  Building steadily through a syllabus, it will be relevant to almost all undergraduate physics degrees which include an option on hydrodynamics, or a course in which hydrodynamics figures prominently.

  13. SLAC physicists develop test for string theory

    CERN Multimedia

    Yajnik, Juhi

    2006-01-01

    "Under certain conditions, string theory solves many of the questions wracking the minds of physicists, but until recently it had one major flaw - it could not be tested. SLAC (Stanford Linear Accelerator Center) scientists have found a way to test this revolutionary theory, which posits that there are 10 or 11 dimensions in our universe" (1 page)

  14. Particle physicists want to expand open access

    CERN Multimedia

    Kaiser, Jocelyn

    2006-01-01

    "Particle physicists have come up with a novel way to promote free, immediate access to journal articles. Led by CERN, the giant lab near Geneva, Switzerland, thay want to raise at lesat $6 million a year to begin buying open access to all published papers in their field." (1/2 page)

  15. Physicist challenges prevailing view of math

    CERN Multimedia

    Burton, H

    2004-01-01

    Article about Michael Berry, a renowned mathematical physicist from the University of Bristol in England. Rather than trying to discover profound mathematical relationships in the physical world, Prof. Berry looks to the real world for "applications" of mathematical relationships (1 page)

  16. Physics Climate as Experienced by LGBT+ Physicists

    Science.gov (United States)

    Long, Elena

    2012-02-01

    In 2009, Elena Long created the LGBT+ Physicists website (http://lgbtphysicists.x10hosting.com) as a warehouse for resources useful for sexual and gender minorities working in physics. This resource has grown to include networking resources, lists of LGBT-friendly universities and localities, recommendations for enacting positive change in physics communities, and out-reach to other STEM-oriented LGBT organizations. This has been possible in large part by the dynamic community of LGBT+ physicists and allies looking to make physics more welcoming towards our community. In 2011, Elena used hir position as Member at Large on the executive committee of the Forum of Graduate Student Affairs (FGSA) to conduct a climate survey that included, among other things, the first serious look at LGBT+ demographics in physics. The survey focused particularly on issues of language heard and harassment experienced by physicists and was broken down into categories based on race, physical and mental ability, gender, and sexuality. Furthermore, it examined the outcomes of experienced harassment and the reasons for when harassment was not reported. Due to the nature of the study, overlapping demographics, especially ``multiple minorities,'' were also explored. This talk will give a brief history of the LGBT+ Physicists resource as well as an overview of the FGSA study.

  17. Directory and survey of particle physicists

    International Nuclear Information System (INIS)

    1997-04-01

    In order to develop a clearer understanding of the demographics of the U.S. particle physics workforce, the US Department of Energy, the National Science Foundation, and the Division of Particles and Fields of the American Physical Society commissioned a survey and census of particle physicists employed in the United States. This survey and census were conducted in 1995, with an update of the census in April 1997. The agencies and the scientific community were represented for the 1995 efforts by Dr. Robert Woods (DOE), Dr. William Chinowsky (NSF), and Prof. Uriel Nauenberg (DPF); for the current census, by Dr. Robert Diebold (DOE), Dr. Marvin Goldberg (NSF), and Dr. Patricia Rankin (NSF). The survey/census were carried out with the assistance of the Particle Data Group at Lawrence Berkeley National Laboratory. In order to obtain an accurate study of the current workforce and of future needs, we requested that all HEP physicists fill out and return the 1995 survey. There were 2494 respondents. For the 1997 census, a representative of each university and laboratory was asked to provide information on all persons at that institution who spend at least 50% of their research time on particle physics. In some cases this includes accelerator physicists. The total number of physicists in the 1997 census is 3492 from 155 institutions in the United States. The full survey questionnaires are shown. The primary one was addressed to individual particle physicists, while the secondary one was addressed to principal investigators and sought information about people leaving the field. There are many possible tables and plots from this survey, with a variety of correlations. Those chosen are representative of a cross-section of the demographic results. It should be emphasized that this survey was a snapshot in time, and does not have the same capabilities as would a series of surveys that are periodic in time. Care should be taken in interpreting the results of the tables and plots

  18. Directory and survey of particle physicists

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    In order to develop a clearer understanding of the demographics of the U.S. particle physics workforce, the US Department of Energy, the National Science Foundation, and the Division of Particles and Fields of the American Physical Society commissioned a survey and census of particle physicists employed in the United States. This survey and census were conducted in 1995, with an update of the census in April 1997. The agencies and the scientific community were represented for the 1995 efforts by Dr. Robert Woods (DOE), Dr. William Chinowsky (NSF), and Prof. Uriel Nauenberg (DPF); for the current census, by Dr. Robert Diebold (DOE), Dr. Marvin Goldberg (NSF), and Dr. Patricia Rankin (NSF). The survey/census were carried out with the assistance of the Particle Data Group at Lawrence Berkeley National Laboratory. In order to obtain an accurate study of the current workforce and of future needs, we requested that all HEP physicists fill out and return the 1995 survey. There were 2494 respondents. For the 1997 census, a representative of each university and laboratory was asked to provide information on all persons at that institution who spend at least 50% of their research time on particle physics. In some cases this includes accelerator physicists. The total number of physicists in the 1997 census is 3492 from 155 institutions in the United States. The full survey questionnaires are shown. The primary one was addressed to individual particle physicists, while the secondary one was addressed to principal investigators and sought information about people leaving the field. There are many possible tables and plots from this survey, with a variety of correlations. Those chosen are representative of a cross-section of the demographic results. It should be emphasized that this survey was a snapshot in time, and does not have the same capabilities as would a series of surveys that are periodic in time. Care should be taken in interpreting the results of the tables and plots.

  19. Semiconductor Manufacturing equipment introduction

    International Nuclear Information System (INIS)

    Im, Jong Sun

    2001-02-01

    This book deals with semiconductor manufacturing equipment. It is comprised of nine chapters, which are manufacturing process of semiconductor device, history of semiconductor manufacturing equipment, kinds and role of semiconductor manufacturing equipment, construction and method of semiconductor manufacturing equipment, introduction of various semiconductor manufacturing equipment, spots of semiconductor manufacturing, technical elements of semiconductor manufacturing equipment, road map of technology of semiconductor manufacturing equipment and semiconductor manufacturing equipment in the 21st century.

  20. Spectroscopic analysis of optoelectronic semiconductors

    CERN Document Server

    Jimenez, Juan

    2016-01-01

    This book deals with standard spectroscopic techniques which can be used to analyze semiconductor samples or devices, in both, bulk, micrometer and submicrometer scale. The book aims helping experimental physicists and engineers to choose the right analytical spectroscopic technique in order to get specific information about their specific demands. For this purpose, the techniques including technical details such as apparatus and probed sample region are described. More important, also the expected outcome from experiments is provided. This involves also the link to theory, that is not subject of this book, and the link to current experimental results in the literature which are presented in a review-like style. Many special spectroscopic techniques are introduced and their relationship to the standard techniques is revealed. Thus the book works also as a type of guide or reference book for people researching in optical spectroscopy of semiconductors.

  1. Semiconductor spintronics

    CERN Document Server

    Xia, Jianbai; Chang, Kai

    2012-01-01

    Semiconductor Spintronics, as an emerging research discipline and an important advanced field in physics, has developed quickly and obtained fruitful results in recent decades. This volume is the first monograph summarizing the physical foundation and the experimental results obtained in this field. With the culmination of the authors' extensive working experiences, this book presents the developing history of semiconductor spintronics, its basic concepts and theories, experimental results, and the prospected future development. This unique book intends to provide a systematic and modern foundation for semiconductor spintronics aimed at researchers, professors, post-doctorates, and graduate students, and to help them master the overall knowledge of spintronics.

  2. Fermi: a physicist in the upheaval

    International Nuclear Information System (INIS)

    Maria, M. de

    2002-01-01

    This book summarizes the life, works and complex personality of the Italian physicist Enrico Fermi (1901-1954) whose myth is linked with the political upheaval of the 2. world war: the youth of an autodidact, the theorician and the quantum mechanics, his invention of a quantum statistics, the weak interaction theory, his works on artificial radioactivity, the end of the Fermi team and his exile in the USA, the secrete researches at the university of Columbia and the birth of the first atomic 'pile' (December 2, 1942), the building of Los Alamos center and the Alamogordo explosion test, the disagreements among the physicists of the Manhattan project and the position of Fermi, Fermi's contribution in the H-bomb construction, the creation of the physics school of Chicago, the Oppenheimer spying affair. (J.S.)

  3. The ethics of physicists in questions

    CERN Multimedia

    2000-01-01

    Four CERN physicists, Peggie Rimmer, Ugo Amaldi, Alain Blondel, and Jean-Marie Le Goff, answered questions from 150 college students last Monday during a debate on the theme of the ethics of physics. Organized by CERN and the Department of public instruction of the Canton of Geneva, the meeting followed a reading by the students of the play Die Physiker, by Friedrich Dürrenmatt, which raises the problem of political exploitation of discoveries made during the second world war. The Minister of Education of the Canton de Genève, Mrs Martine Brunschwig-Graf, took part in the debate. The questions posed by students were not lacking in pertinence : Should a physicist reveal a discovery that is dangerous in his opinion ? Who are responsible, those who make the discoveries or those who use them ?

  4. Radiation oncology a physicist's-eye view

    CERN Document Server

    Goitein, Michael

    2007-01-01

    Radiation Oncology: A Physicist's-Eye View was written for both physicists and medical oncologists with the aim of helping them approach the use of radiation in the treatment of cancer with understanding, confidence, and imagination. The book will let practitioners in one field understand the problems of, and find solutions for, practitioners in the other. It will help them to know "why" certain approaches are fruitful while, at the same time, encouraging them to ask the question "Why not?" in the face of assertions that some proposal of theirs is impractical, unreasonable, or impossible. Unlike a textbook, formal and complete developments of the topics are not among the goals. Instead, the reader will develop a foundation for understanding what the author has found to be matters of importance in radiation oncology during over thirty years of experience. Presentations cover, in largely non-technical language, the principal physical and biological aspects of radiation treatment and address practical clinical c...

  5. Development of the Future Physicists of Florida

    Science.gov (United States)

    Wade, A.; Weatherford, C.; Cottle, P.; Fannin, S.; Roberts, W.; Fauerbach, M.; Ponti, L.; Sear, J.

    2013-03-01

    We present the development of the ``Future Physicists of Florida'' (FPF) comprised of Florida university physics professors, middle and high school science teachers, and backed by the Florida Legislature. Our purpose is to address the lack of incoming college freshmen ready and willing to become physics majors. We will discuss the building of FPF and the development of a pipeline for middle and high school students predicted to produce the optimal number of bachelor's degrees in STEM. We will also discuss our use of community-building activities to educate the students, and their parents and teachers about the educational value of taking physics before going to college and potential careers in physics, to entertain them with fun physics related activities in order to peak their interest in physics, and to ultimately inspire the students to become physicists.

  6. The Status of Women Physicists in Pakistan

    Science.gov (United States)

    Hasnain, Aziz Fatima; Islam, Jabeen

    2009-04-01

    A significant number of women physicists work in high-ranking positions in the universities and research institutes of Pakistan; however, the number of women is much lower compared with men. We surveyed these women about the challenges they faced in the workplace and the pace of their progress and scientific work in a male-dominant society. We also surveyed girls' attitudes toward studying physics at the graduate and undergraduate levels.

  7. Feedback between Accelerator Physicists and magnet builders

    International Nuclear Information System (INIS)

    Peggs, S.

    1995-01-01

    Our task is not to record history but to change it. (K. Marx (paraphrased)) How should Accelerator Physicists set magnet error specifications? In a crude social model, they place tolerance limits on undesirable nonlinearities and errors (higher order harmonics, component alignments, etc.). The Magnet Division then goes away for a suitably lengthy period of time, and comes back with a working magnet prototype that is reproduced in industry. A better solution is to set no specifications. Accelerator Physicists begin by evaluating expected values of harmonics, generated by the Magnet Division, before and during prototype construction. Damaging harmonics are traded off against innocuous harmonics as the prototype design evolves, lagging one generation behind the evolution of expected harmonics. Finally, the real harmonics are quickly evaluated during early industrial production, allowing a final round of performance trade-offs, using contingency scenarios prepared earlier. This solution assumes a close relationship and rapid feedback between the Accelerator Physicists and the magnet builders. What follows is one perspective of the way that rapid feedback was used to 'change history' (improve linear and dynamic aperture) at RHIC, to great benefit

  8. Small ripple shakes a roomful of physicists

    CERN Multimedia

    2011-01-01

    After the exciting results announced by CERN physicists at the EPS conference, the CERN Quantum Diaries blog gave an insightful recap of the news. Here's what blogger, Pauline Gagnon, reported...   The CMS collaboration combined results for the Higgs boson search covering a possible Higgs in the region from 110 to 600 GeV. This Friday afternoon, the 750 physicists attending the European Physics Society meeting in Grenoble, France, were pleasantly surprised. The audience was waiting with some anticipation to see the first important set of results from the two large LHC experiments, ATLAS and CMS on the search for the Higgs boson. In fact, for the past two days, results had been shown from both experiments as well as from the Tevatron experiments in various individual channels. But today, the latest combined results from each experiment were shown in public for the first time. Of course, all physicists belonging either to the CMS or ATLAS experiment had had a chance t...

  9. Semiconductor spintronics

    International Nuclear Information System (INIS)

    Fabian, J.; Abiague, A.M.; Ertler, Ch.; Stano, P.; Zutic, I.

    2007-01-01

    Spintronics refers commonly to phenomena in which the spin of electrons in a solid state environment plays the determining role. In a more narrow sense spintronics is an emerging research field of electronics: spintronics devices are based on a spin control of electronics, or on an electrical and optical control of spin of magnetism. While metal spintronics has already found its niche in the computer industry - giant magnetoresistance systems are used as hard disk read heads - semiconductor spintronics is vet demonstrate its full potential. This review presents selected themes of semiconductor spintronics, introducing important concepts in spin transport, spin transport, spin injection. Silsbee-Johnson spin-charge coupling, and spin-dependent tunneling, as well as spin relaxation and spin dynamics. The most fundamental spin-dependent interaction in nonmagnetic semiconductors is spin-orbit coupling. Depending on the crystal symmetries of the material, as well as on the structural properties of semiconductor based heterostructures, the spin-orbit coupling takes on different functional forms, giving a nice playground of effective spin-orbit Hamiltonians. The effective Hamiltonians for the most relevant classes of materials and heterostructures are derived here from realistic electronic band structure descriptions. Most semiconductor device systems are still theoretical concepts, waiting for experimental demonstrations. A review of selected proposed, and a few demonstrated devices is presented, with detailed description of two important classes: magnetic resonant tunnel structures and bipolar magnetic diodes and transistors. In view of the importance of ferromagnetic semiconductor material, a brief discussion of diluted magnetic semiconductors is included. In most cases the presentation is of tutorial style, introducing the essential theoretical formalism at an accessible level, with case-study-like illustrations of actual experimental results, as well as with brief

  10. Brief, Embedded, Spontaneous Metacognitive Talk Indicates Thinking Like a Physicist

    Science.gov (United States)

    Sayre, Eleanor C.; Irving, Paul W.

    2015-01-01

    Instructors and researchers think "thinking like a physicist" is important for students' professional development. However, precise definitions and observational markers remain elusive. We reinterpret popular beliefs inventories in physics to indicate what physicists think thinking like a physicist entails. Through discourse analysis of…

  11. Semiconductor statistics

    CERN Document Server

    Blakemore, J S

    1962-01-01

    Semiconductor Statistics presents statistics aimed at complementing existing books on the relationships between carrier densities and transport effects. The book is divided into two parts. Part I provides introductory material on the electron theory of solids, and then discusses carrier statistics for semiconductors in thermal equilibrium. Of course a solid cannot be in true thermodynamic equilibrium if any electrical current is passed; but when currents are reasonably small the distribution function is but little perturbed, and the carrier distribution for such a """"quasi-equilibrium"""" co

  12. Mathematical methods for physicists a comprehensive guide

    CERN Document Server

    Arfken, George B; Harris, Frank E

    2012-01-01

    Now in its 7th edition, Mathematical Methods for Physicists continues to provide all the mathematical methods that aspiring scientists and engineers are likely to encounter as students and beginning researchers. This bestselling text provides mathematical relations and their proofs essential to the study of physics and related fields. While retaining the key features of the 6th edition, the new edition provides a more careful balance of explanation, theory, and examples. Taking a problem-solving-skills approach to incorporating theorems with applications, the book's improved focus w

  13. The Experiences of an Entrepreneurial Physicist

    Science.gov (United States)

    Kermani, Moe

    2012-10-01

    The majority of pre- and post-graduate training in physics is focused on the acquisition of hard skills necessary to pursue academic research within a specific discipline of the broader field. Often many physics graduates view a career transition from academia to the private sector with much consternation. In this presentation, Moe Kermani will share his experience in making the transition and discuss how elements of post graduate training in physics provide a good foundation for success as an entrepreneur. This presentation is primarily aimed at young physicists and graduate students that are considering a transition from the academic sector to the world of technology startups.

  14. Physicists make the most of antimatter

    International Nuclear Information System (INIS)

    Kalmus, Peter

    1987-01-01

    The paper concerns the detection and creation of antimatter. The concept of antimatter was first suggested by Schuster in 1898, was predicted by Dirac in the 1930's and discovered in an accelerator experiment in California in the 1950's. So far, physicists have found no evidence of large amounts of antimatter in nature. However, the creation of artificial antimatter in the laboratory is a possibility. The facilities at CERN should enable the making of antimatter, by using the antiproton beam from LEAR, to make antihydrogen. (UK)

  15. Semiconductor Detectors

    International Nuclear Information System (INIS)

    Cortina, E.

    2007-01-01

    Particle detectors based on semiconductor materials are among the few devices used for particle detection that are available to the public at large. In fact we are surrounded by them in our daily lives: they are used in photoelectric cells for opening doors, in digital photographic and video camera, and in bar code readers at supermarket cash registers. (Author)

  16. Building 887: An Aladdin's Cave for Physicists

    CERN Multimedia

    2001-01-01

    Building 887 on the Prévessin site is home to numerous experiments bringing together physicists and engineers from around the world. Its diversity makes the huge building a replica of CERN in miniature. The Installation unit of the SL EA group in front of the support structure for the ATLAS muon chambers. From left to right, seated: Pierre Gimenez, Yves Bonnet, Yves Naveau, Alain Pinget, Christian Becquet, Camille Adenot; standing: Philippe Guillot, Thierry Reynes, Monserrat Zurita-Perez, Claude Ferrari et Denis Gacon. The big wheel to be used for the ATLAS muon chambers (see below) is much the most spectacular installation currently occupying Building 887. But it is far from being the only attraction. Push open the heavy doors of this immense hall and it is a bit like entering a physicists' Aladdin's cave. The building, 55 metres wide and 300 metres long, is a treasure trove of engineering and technology, a CERN in miniature, housing dozens of collaborations from all over the world. With its 150...

  17. What physicists should know about finance

    Science.gov (United States)

    Schmidt, Anatoly B.

    2005-05-01

    There has been growing interest in Econophysics, i.e. analysis and modeling of financial time series using the theoretical Physics concepts (scaling, fractals, chaos). Besides the scientific stimuli, this interest is backed by perception that the financial industry is a viable alternative for those physicists who are not able or are not willing to pursue an academic career. However, the times when any Ph.D. in Physics had a chance to find a job on the Wall Street are gone (if they ever existed). Indeed, not every physicist wields the stochastic calculus, non-normal statistical distributions, and the methods of time series analysis. Moreover, now that many universities offer courses in mathematical finance, the applicants for quantitative positions in finance are expected to know such concepts as option pricing, portfolio management, and risk measurement. Here I describe a synthetic course based on my book [1] that outlines both worlds: Econophysics and Mathematical Finance. The course may be offered as elective for senior undergraduate or graduate Physics majors.

  18. Semiconductor sensors

    International Nuclear Information System (INIS)

    Hartmann, Frank

    2011-01-01

    Semiconductor sensors have been around since the 1950s and today, every high energy physics experiment has one in its repertoire. In Lepton as well as Hadron colliders, silicon vertex and tracking detectors led to the most amazing physics and will continue doing so in the future. This contribution tries to depict the history of these devices exemplarily without being able to honor all important developments and installations. The current understanding of radiation damage mechanisms and recent R and D topics demonstrating the future challenges and possible technical solutions for the SLHC detectors are presented. Consequently semiconductor sensor candidates for an LHC upgrade and a future linear collider are also briefly introduced. The work presented here is a collage of the work of many individual silicon experts spread over several collaborations across the world.

  19. Semiconductor Optics

    CERN Document Server

    Klingshirn, Claus F

    2012-01-01

    This updated and enlarged new edition of Semiconductor Optics provides an introduction to and an overview of semiconductor optics from the IR through the visible to the UV, including linear and nonlinear optical properties, dynamics, magneto and electrooptics, high-excitation effects and laser processes, some applications, experimental techniques and group theory. The mathematics is kept as elementary as possible, sufficient for an intuitive understanding of the experimental results and techniques treated. The subjects covered extend from physics to materials science and optoelectronics. Significantly updated chapters add coverage of current topics such as electron hole plasma, Bose condensation of excitons and meta materials. Over 120 problems, chapter introductions and a detailed index make it the key textbook for graduate students in physics. The mathematics is kept as elementary as possible, sufficient for an intuitive understanding of the experimental results and techniques treated. The subjects covered ...

  20. Synthesis of the IRSN report on arrangements proposed by AREVA, the CEA and the ILL about the implementation of a 'hard core' for installations related to the fuel cycle and for research reactors falling within batch 1

    International Nuclear Information System (INIS)

    2013-01-01

    After additional safety assessments performed by operators of French nuclear installations, the ASN ask them to implement a 'hard core' of material and organisational arrangements to prevent any severe accident or its propagation, to limit massive releases within a scenario of accident which could not have been controlled, and to allow the operator to ensure its assigned missions in crisis management, to present an organisation and means of crisis management which would remain operational in case of extreme aggressions, and to foresee transient arrangements before the implementation of the crisis management hard core. This report proposes a synthesis of the assessment performed by the IRSN on these issues. It addresses issues on which hard cores are defined (earthquakes, flooding, other climatic aggressions, effects induced by an extreme aggression), requirements associated with material arrangements of hard cores. The content of these hard cores is then discussed for AREVA installations (La Hague, MELOX, Romans-sur-Isere, Tricastin), CEA installations and the high flow reactor of the Laue Langevin Institute. Measures concerning crisis management and, for AREVA, the taking of human and organisational factors into account by these operators are also discussed

  1. Semiconductor annealing

    International Nuclear Information System (INIS)

    Young, J.M.; Scovell, P.D.

    1982-01-01

    A process for annealing crystal damage in ion implanted semiconductor devices in which the device is rapidly heated to a temperature between 450 and 900 0 C and allowed to cool. It has been found that such heating of the device to these relatively low temperatures results in rapid annealing. In one application the device may be heated on a graphite element mounted between electrodes in an inert atmosphere in a chamber. (author)

  2. Paths to Licensure: Things Physicists Should Know

    Science.gov (United States)

    Stewart, Gay; Stewart, John

    2016-03-01

    The path to licensure can be quite complicated, and can thwart a physics department's efforts to produce more and better prepared high school physics teachers. Each state has different pathways to licensure. Acronyms like CAEP and SPA are not within the normal physicist's vocabulary. Some understanding of this topic can allow physics faculty advisers to help our students so that fewer are derailed on their path to the classroom, or take a path that will leave them less well prepared if they do find themselves there. Examples of different approaches that work within state licensure systems from two different states will be presented. Physics teacher preparation efforts in both Arkansas and West Virginia have been supported in part by the Physics Teacher Education Coalition (PhysTEC).

  3. ALICE physicists receive 2014 Lise Meitner Prize

    CERN Multimedia

    Katarina Anthony

    2014-01-01

    On Wednesday, 3 September, four ALICE physicists were presented with the European Physical Society's 2014 Lise Meitner Prize for their outstanding contributions to nuclear physics (see here).   ALICE collaboration members Johanna Stachel (Heidelberg University, Germany), Peter Braun-Munzinger (GSI, Germany), Paolo Giubellino (INFN Turin, Italy, and CERN) and Jürgen Schukraft (CERN) were presented with their awards at a private ceremony held in the Globe of Science and Innovation. In addition to members of the ALICE collaboration, the ceremony was attended by members of the CERN Management including the Director-General, Rolf Heuer, as well as the EPS Nuclear Physics Board Chair, Douglas MacGregor, and the EPS Lise Meitner Prize Committee Chair, Victor Zamfir. For more information, please see "EPS honours CERN's heavy-ion researchers".  From left to right: Douglas MacGregor (EPS); Prize recipients Jürgen Schukraft,&a...

  4. A course in mathematical methods for physicists

    CERN Document Server

    Herman, Russell L

    2014-01-01

    Based on the author’s junior-level undergraduate course, this introductory textbook is designed for a course in mathematical physics. Focusing on the physics of oscillations and waves, A Course in Mathematical Methods for Physicists helps students understand the mathematical techniques needed for their future studies in physics. It takes a bottom-up approach that emphasizes physical applications of the mathematics. The book offers: •A quick review of mathematical prerequisites, proceeding to applications of differential equations and linear algebra •Classroom-tested explanations of complex and Fourier analysis for trigonometric and special functions •Coverage of vector analysis and curvilinear coordinates for solving higher dimensional problems •Sections on nonlinear dynamics, variational calculus, numerical solutions of differential equations, and Green's functions

  5. C++ FOR PARTICLE PHYSICISTS By Paul Kunz

    CERN Document Server

    TECHNICAL TRAINING; Tel. 74460

    2001-01-01

    Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on March 5 to 9. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page : http://www.cern.ch/Training/ENSTEC/P9798/Software/cpppp_e.htm Team Visitors should ask their Group Leader to send an e-mail to the DTO of EP Division, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent.

  6. C++ FOR PARTICLE PHYSICISTS by Paul Kunz

    CERN Document Server

    Technical Training; Tel. 74460

    2001-01-01

    Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on March 5 to 9. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page : http://www.cern.ch/Training/ENSTEC/P9798/Software/cpppp_e.htm Team Visitors should ask their Group Leader to send an e-mail to the DTO of EP Division, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent.

  7. Improving the workplace environment for female physicists

    Science.gov (United States)

    Butcher, Gillian

    2013-03-01

    The ideal workplace is one in which women and men can work to their potential and are respected and recognized for their contribution. But what are the conditions that would create this environment, and how can we achieve this? This paper highlights some of the best practices, discussed in a single-session workshop, to improve the workplace environment for female (and male) physicists. While there are many actions that can be taken at the personal, local, and even national level, it is necessary to understand when the issues have broader societal implications. Likewise, working toward the ideal environment should not lead us to ignore the necessity of training and assisting women to work effectively in the existing environment.

  8. Academic Training: Practical Statistics for Particle Physicists

    CERN Multimedia

    2006-01-01

    2006-2007 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 9, 10, 11, 12, 13 October from 11:00 to 12:00 - Main Auditorium, bldg. 500, TH Auditorium, bldg 4, 3rd floor, on 13 October Practical Statistics for Particle Physicists L. LYONS, University of Oxford, GB Lecture 1: Learning to love the errror matrix Introductory remarks. Conditional probability. Statistical and systematic errors. Combining results Binomial, Poisson and 1-D Gaussian 2-D Gaussian and the error matrix. Understanding the covariance. Using the error matrix. Estimating the error matrix. Combining correlated measurements Lecture 2: Parameter determination by likelihood: Do's and don'ts Introduction to likelihood. Error estimate. Simple examples: (1) Breit Wigner (2) Lifetime binned and unbinned likelihood several parameters extended maximum likelihood. Common misapprehensions: Normalisation delta(lnL) = 1/2 rule and coverage Integrating the likelihood Unbinned L_max as goodness of fit Punzi effect Lecture 3: Chi-squared and hypothesis test...

  9. Tensor calculus for engineers and physicists

    CERN Document Server

    de Souza Sánchez Filho, Emil

    2016-01-01

    This textbook provides a rigorous approach to tensor manifolds in several aspects relevant for Engineers and Physicists working in industry or academia. With a thorough, comprehensive, and unified presentation, this book offers insights into several topics of tensor analysis, which covers all aspects of N dimensional spaces. The main purpose of this book is to give a self-contained yet simple, correct and comprehensive mathematical explanation of tensor calculus for undergraduate and graduate students and for professionals. In addition to many worked problems, this book features a selection of examples, solved step by step. Although no emphasis is placed on special and particular problems of Engineering or Physics, the text covers the fundamentals of these fields of science. The book makes a brief introduction into the basic concept of the tensorial formalism so as to allow the reader to make a quick and easy review of the essential topics that enable having the grounds for the subsequent themes, without need...

  10. Gustav-Hertz-Prize for CERN Physicist

    CERN Multimedia

    2004-01-01

    Klaus Blaum, of GSI Darmstadt and project leader of the ISOLTRAP experiment at CERN, will receive the 2004 Gustav-Hertz-Prize for his outstanding work on the mass determination of unstable atomic nuclei. Blaum extended the measuring capability of the ISOLTRAP experiment at the ISOLDE facility, which studies short-lived isotopes, by installing a source of carbon clusters. Using these carbon clusters as mass reference allows researchers to obtain higher-precision and absolute atomic mass measurements which are important to understand the weak interaction and the synthesis of chemical elements. The Gustav-Hertz-Prize is awarded to outstanding young physicists and is endowed with 7500 euro. It will be awarded at the Spring Conference of the German Physical Society in Munich on 24 March.

  11. International young physicists' tournament problems & solutions 2014

    CERN Document Server

    Gao, Wenli

    2016-01-01

    International Young Physicists' Tournament (Iypt), is one of the most prestigious international physics contests among high school students. This book is based on the solutions of 2014 Iypt problems. The authors are undergraduate students who participated in the Cupt (Chinese Undergraduate Physics Tournament). It is intended as a college level solution to the challenging open-ended problems. It provides original, quantitative solutions in fulfilling seemingly impossible tasks. This book is not limited to the tasks required by the problems and it is not confined to the models and methods in present literatures. Many of the articles include modification and extension to existing models in references, or derivation and computation based on fundamental physics. This book provides quantitative solutions to practical problems in everyday life. This is a good reference book for undergraduates, advanced high-school students, physics educators and curious public interested in the intriguing phenomena in daily life.

  12. Technical Training: C++ for Particle Physicists

    CERN Multimedia

    Monique Duval

    2004-01-01

    Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on 15 - 19 November. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page: Team Visitors should ask their Group Leader to send an e-mail to the DTO of PH Department, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent. ENSEIGNEMENT TECHNIQUE TECHNICAL TRAINING Monique Duval 74924 technical.training@cern.ch

  13. Technical Tarining: C++ for Particle Physicists

    CERN Multimedia

    Monique Duval

    2005-01-01

    Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on 7-11 March. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page : http://cern.ch/TechnicalTraining/ENSTEC/p2002/Software/cpppp_e.asp Team Visitors should ask their Group Leader to send an e-mail to the DTO of PH Department, M. Burri, referring to the ‘C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent. ENSEIGNEMENT TECHNIQUE TECHNICAL TRAINING Monique Duval 74924 technical.training@cern.ch

  14. Technical Training: C++ for Particle Physicists

    CERN Multimedia

    Monique Duval

    2005-01-01

    Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on 7-11 March. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page : http://cern.ch/TechnicalTraining/ENSTEC/p2002/Software/cpppp_e.asp Team Visitors should ask their Group Leader to send an e-mail to the DTO of PH Department, M. Burri, referring to the ‘C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent. ENSEIGNEMENT TECHNIQUE TECHNICAL TRAINING Monique Duval 74924 technical.training@cern.ch

  15. Technical Training: C++ for Particle Physicists

    CERN Multimedia

    Monique Duval

    2004-01-01

    Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on 15 - 19 November. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page. Team Visitors should ask their Group Leader to send an e-mail to the DTO of PH Department, M. Burri, referring to the 'C++ for Particle Physicists' course and giving their name, CERN ID number, the Team account number to which the course fee should be charged, and VERY IMPORTANTLY an email address to which an invitation to the course can be sent. ENSEIGNEMENT TECHNIQUE TECHNICAL TRAINING Monique Duval 74924 technical.training@cern.ch

  16. Bird of passage recollections of a physicist

    CERN Document Server

    1985-01-01

    Here is the intensely personal and often humorous autobiography of one of the most distinguished theoretical physicists of his generation, Sir Rudolf Peierls. Born in Germany in 1907, Peierls was indeed a bird of passage," whose career of fifty-five years took him to leading centers of physics--including Munich, Leipzig, Zurich, Copenhagen, Cambridge, Manchester, Oxford, and J. Robert Oppenheimer''s Los Alamos. Peierls was a major participant in the revolutionary development of quantum mechanics in the 1920s and 1930s, working with some of the pioneers and, as he puts it, "some of the great characters" in this field. Originally published in 1988. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of- print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Libr...

  17. School for Young High Energy Physicists

    CERN Document Server

    Evans, M E

    2003-01-01

    Forty-seven experimental particle physicists attended the 2002 Summer School, held, as usual, at The Cosener's House in Abingdon during September. The weather was glorious allowing a number of tutorials and impromptu seminars to take place in the lovely gardens. The lectures were of a high standard and were delivered and received enthusiastically, providing material for lively discussions in tutorials and elsewhere. The students each gave a ten-minute seminar and the general quality of the talks was impressive and the time keeping excellent. The activities described ranged from front-line physics analysis to preparations for the next generation of machines and detectors, and gave a clear indication of the breadth of particle physics activities in the UK

  18. Probabilistic interpretation of data a physicist's approach

    CERN Document Server

    Miller, Guthrie

    2013-01-01

    This book is a physicists approach to interpretation of data using Markov Chain Monte Carlo (MCMC). The concepts are derived from first principles using a style of mathematics that quickly elucidates the basic ideas, sometimes with the aid of examples. Probabilistic data interpretation is a straightforward problem involving conditional probability. A prior probability distribution is essential, and examples are given. In this small book (200 pages) the reader is led from the most basic concepts of mathematical probability all the way to parallel processing algorithms for Markov Chain Monte Carlo. Fortran source code (for eigenvalue analysis of finite discrete Markov Chains, for MCMC, and for nonlinear least squares) is included with the supplementary material for this book (available online).

  19. Semiconductors put spin in spintronics

    International Nuclear Information System (INIS)

    Weiss, Dieter

    2000-01-01

    Electrons and holes, which carry the current in semiconductor devices, are quantum-mechanical objects characterized by a set of quantum numbers - the band index, the wave-vector (which is closely related to the electron or hole velocity) and spin. The spin, however, is one of the strangest properties of particles. In simple terms, we can think of the spin as an internal rotation of the electron, but it has no classical counterpart. The spin is connected to a quantized magnetic moment and hence acts as a microscopic magnet. Thus the electron spin can adopt one of two directions (''up'' or ''down'') in a magnetic field. The spin plays no role in conventional electronics and the current in any semiconductor device is made up of a mixture of electrons with randomly oriented spins. However, a new range of electronic devices that transport the spin of the electrons, in addition to their charge, is being developed. But the biggest obstacle to making practical ''spin electronic'' or ''spintronic'' devices so far has been finding a way of injecting spin-polarized electrons or holes into the semiconductor and then detecting them. Recently a team of physicists from the University of Wuerzburg in Germany, and also a collaboration of researchers from Tohoku University in Japan and the University of California at Santa Barbara, have found a way round these problems using either semi-magnetic or ferromagnetic semiconductors as ''spin aligners'' (R Fiederling et al. 1999 Nature 402 787; Y Ohno et al. 1999 Nature 402 790). In this article the author presents the latest breakthrough in spintronics research. (UK)

  20. Semiconductor annealing

    International Nuclear Information System (INIS)

    Young, J.M.; Scovell, P.D.

    1981-01-01

    A process for annealing crystal damage in ion implanted semiconductor devices is described in which the device is rapidly heated to a temperature between 450 and 600 0 C and allowed to cool. It has been found that such heating of the device to these relatively low temperatures results in rapid annealing. In one application the device may be heated on a graphite element mounted between electrodes in an inert atmosphere in a chamber. The process may be enhanced by the application of optical radiation from a Xenon lamp. (author)

  1. Great Physicists - The Life and Times of Leading Physicists from Galileo to Hawking

    International Nuclear Information System (INIS)

    Cropper, William H

    2002-01-01

    The author, a former American chemistry professor, has organized his book into nine parts with 29 chapters, covering, in a fairly historical sequence and systematic conceptual progression, all fundamentals of today's physics: i.e., mechanics, thermodynamics, electromagnetism, statistical mechanics, relativity, quantum mechanics, nuclear physics, particle physics, astronomy-astrophysics-cosmology. Obviously, the 20th century (when about 90% of professional physicists of all time worked) assumes with five topics the dominant role in this enterprise. For each topic, a small number (ranging from one to eight) of leading personalities is selected and the biographies of these 29 physicists, including two women (Marie Curie and Lise Meitner), are presented in some detail together with their achievements in the particular topic. Important relevant contributions of other scholars to each topic are also discussed. In addition, Cropper provides each of the topics with a short 'historical synopsis' justifying his selection of key persons. One may argue that concentrating on leading physicists constitutes an old-fashioned approach to displaying the history and contents of fundamental topics in physics. However, the mixture of biographies and explanation of leading contributions given here will certainly serve for a larger public, not just professional physicists and scientists, as a guide through the exciting development of physical ideas and discoveries. In general, the presentation of the material is quite satisfactory (with only few slips, e.g., in the Meitner story, where the author follows too closely a new biography) and gives the essence of the great advances in physics since the 15th century. One notices perhaps the limitation of the author in cases where no biography in English is available - this would also explain the omission of some of the main contributors to atomic and particle physics, such as Arnold Sommerfeld and Hideki Yukawa, or that French or Russian

  2. BOOK REVIEW: Great Physicists - The Life and Times of Leading Physicists from Galileo to Hawking

    Science.gov (United States)

    Cropper, William H.

    2002-11-01

    The author, a former American chemistry professor, has organized his book into nine parts with 29 chapters, covering, in a fairly historical sequence and systemtic conceptual progression, all fundamentals of today's physics: i.e., mechanics, thermodynamics, electromagnetism, statistical mechanics, relativity, quantum mechanics, nuclear physics, particle physics, astronomy-astrophysics-cosmology. Obviously, the 20th century (when about 90% of professional physicists of all time worked) assumes with five topics the dominant role in this enterprise. For each topic, a small number (ranging from one to eight) of leading personalities is selected and the biographies of these 29 physicists, including two women (Marie Curie and Lise Meitner), are presented in some detail together with their achievements in the particular topic. Important relevant contributions of other scholars to each topic are also discussed. In addition, Cropper provides each of the topics with a short 'historical synopsis' justifying his selection of key persons. One may argue that concentrating on leading physicists constitutes an old-fashioned approach to displaying the history and contents of fundamental topics in physics. However, the mixture of biographies and explanation of leading contributions given here will certainly serve for a larger public, not just professional physicists and scientists, as a guide through the exciting development of physical ideas and discoveries. In general, the presentation of the material is quite satisfactory (with only few slips, e.g., in the Meitner story, where the author follows too closely a new biography) and gives the essence of the great advances in physics since the 15th century. One notices perhaps the limitation of the author in cases where no biography in English is available - this would also explain the omission of some of the main contributors to atomic and particle physics, such as Arnold Sommerfeld and Hideki Yukawa, or that French or Russian readers

  3. Universities prepare as physicists plan to pop protons

    CERN Multimedia

    2007-01-01

    "The world's largest science experiment, a physics experiment designed to determine the nature of matter, will produce a mountain of data. And because the world's physicists cannot move to the mountain, an army of computer research scientists is preparing to move the mountain to the physicists." (3 pages)

  4. Magnetic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Bihler, Christoph

    2009-04-15

    In this thesis we investigated in detail the properties of Ga{sub 1-x}Mn{sub x}As, Ga{sub 1-x}Mn{sub x}P, and Ga{sub 1-x}Mn{sub x}N dilute magnetic semiconductor thin films with a focus on the magnetic anisotropy and the changes of their properties upon hydrogenation. We applied two complementary spectroscopic techniques to address the position of H in magnetic semiconductors: (i) Electron paramagnetic resonance, which provides direct information on the symmetry of the crystal field of the Mn{sup 2+} atoms and (ii) x-ray absorption fine structure analysis which allows to probe the local crystallographic neighborhood of the absorbing Mn atom via analysing the fine structure at the Mn K absorption edge. Finally, we discussed the obstacles that have to be overcome to achieve Curie temperatures above the current maximum in Ga{sub 1-x}Mn{sub x}As of 185 K. Here, we outlined in detail the generic problem of the formation of precipitates at the example of Ge:MN. (orig.)

  5. Academic Training: Cosmology for particle physicists

    CERN Multimedia

    Françoise Benz

    2005-01-01

    2004-2005 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 9, 10, 11, 12 & 13 May from 11.00 to 12.00 hrs - Main Auditorium, bldg. 500 on 9, 10, 12 and 13 May, Council Chamber, bldg. 503, on 11 May Cosmology for particle physicists S. CARROLL / Enrico Fermi Institute, Univ. of Chicago, USA The past few years have seen dramatic breakthroughs and spectacular and puzzling discoveries in astrophysics and cosmology. We know much about the universe, but understand very little. Open questions include the nature of the dark matter and dark energy, the origin of the matter/antimatter asymmetry, the possibility of inflation, and the role of string theory and extra dimensions in the early universe. All of these issues impact strongly on, and will be heavily influenced by, upcoming experiments in particle physics. I will give an overview of current questions at the overlap of cosmology and particle physics, and discuss some theoretical and experimental questions likely to be important in the near future. ENSEIG...

  6. Academic Training: Cosmology for particle physicists

    CERN Multimedia

    Françoise Benz

    2005-01-01

    2004-2005 ACADEMIC TRAINING PROGRAMMELECTURE SERIES9, 10, 11, 12 & 13 Mayfrom 11.00 to 12.00 hrs - Main Auditorium, bldg. 500 on 9, 10, 12 and 13 May, Council Chamber, bldg. 503, on 11 MayCosmology for particle physicistsS. CARROLL / Enrico Fermi Institute, Univ. of Chicago, USAThe past few years have seen dramatic breakthroughs and spectacular and puzzling discoveries in astrophysics and cosmology. We know much about the universe, but understand very little. Open questions include the nature of the dark matter and dark energy, the origin of the matter/antimatter asymmetry, the possibility of inflation, and the role of string theory and extra dimensions in the early universe. All of these issues impact strongly on, and will be heavily influenced by, upcoming experiments in particle physics. I will give an overview of current questions at the overlap of cosmology and particle physics, and discuss some theoretical and experimental questions likely to be important in the near future.ENSEIGNEMENT ACADEMIQUEAC...

  7. Academic Training: Cosmology for particle physicists

    CERN Multimedia

    Françoise Benz

    2005-01-01

    2004-2005 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 9, 10, 11, 12 & 13 May from 11.00 to 12.00 hrs - Main Auditorium, bldg. 500 on 9, 10, 12 and 13 May, Council Chamber, bldg. 503, on 11 May Cosmology for particle physicists S. CARROLL / Enrico Fermi Institute, Univ. of Chicago, USA The past few years have seen dramatic breakthroughs and spectacular and puzzling discoveries in astrophysics and cosmology. We know much about the universe, but understand very little. Open questions include the nature of the dark matter and dark energy, the origin of the matter/antimatter asymmetry, the possibility of inflation, and the role of string theory and extra dimensions in the early universe. All of these issues impact strongly on, and will be heavily influenced by, upcoming experiments in particle physics. I will give an overview of current questions at the overlap of cosmology and particle physics, and discuss some theoretical and experimental questions likely to be important in the near future. ENSEIGNEME...

  8. Lasers take physicists back to school

    CERN Multimedia

    Katarina Anthony

    2012-01-01

    This week saw the First International School on Laser Applications at Accelerators held in GANIL (France). Organised by the LA3NET project – of which CERN is a partner – the school was a singular opportunity for accelerator and laser physicists to meet and discuss the future of the merging areas.   As an EU-funded training network, LA3NET has brought together 27 partner institutes to train early stage researchers in the field of laser applications. Though the network kickedoff only a few months ago, it has already filled 15 of its 17 fellow positions, including three in CERN’s BE and EN Departments. The five-day International School on Laser Applications at Accelerators was the first big event organised by LA3NET, and united participants from both inside and outside the project. “This was the first time a school had linked laser and accelerator physics at such a fundamental level,” says Carsten P. Welsch, a former CERN fellow who now coordinates t...

  9. Why are there so few female physicists?

    CERN Multimedia

    Marianne Johansen

    Physics has always had a relatively low proportion of female students and researchers. In the EU there are on average 33% female PhD-graduates in the physical sciences, while the percentage of female professors amounts to 9% [1]. At CERN the proportion is even less with only 6.6 % of the research staff being women [2]. The fact that there is no proportional relationship between the number of PhD-graduates and professors also suggests women are less likely to succeed in an academic career than men [1]. A typical ATLAS plenary meeting. More laptops than women... Is the low representation of women in physics a problem, do we actually need more female physicists? In my view this question has to be answered from three perspectives, the perspective of society, the perspective of science and the perspective of women. The perspective of society Starting from the viewpoint of society, several issues can be raised. Firstly, physics is a field of innovation. Many technological advancements having a huge imp...

  10. Technical Training: C++ for Particle Physicists

    CERN Multimedia

    2004-01-01

    If you wish to participate in one of the following courses, please discuss with your supervisor and apply electronically directly from the course description pages that can be found on the Web at: http://www.cern.ch/Training/ or fill in an "application for training" form available from your Divisional Secretariat or from your DTO (Divisional Training Officer). Applications will be accepted in the order of their receipt. TECHNICAL TRAINING Monique Duval tel. 74924 technical.training@cern.ch Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on 8 - 12 March. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page : http://cern.ch/TechnicalTraining/ENSTEC/p2002/Software/cpppp_e.asp Team Visitors should ask their Group Leader to send an e-mail to the DTO of PH Department, M. Burri, referring to the ‘C++ for Particle Physicists' ...

  11. Technical Training: C++ for Particle Physicists

    CERN Multimedia

    2004-01-01

    If you wish to participate in one of the following courses, please discuss with your supervisor and apply electronically directly from the course description pages that can be found on the Web at: http://www.cern.ch/Training/ or fill in an "application for training" form available from your Divisional Secretariat or from your DTO (Divisional Training Officer). Applications will be accepted in the order of their receipt. TECHNICAL TRAINING Monique Duval tel. 74924 technical.training@cern.ch Please note that Paul Kunz will be giving his very popular and highly recommended C++ course again on 8 - 12 March. The course costs 200 CHF, and advance registration is required. People with CERN EDH accounts can apply electronically directly from the Web course description page: http://cern.ch/TechnicalTraining/ENSTEC/p2002/Software/cpppp_e.asp Team Visitors should ask their Group Leader to send an e-mail to the DTO of PH Department, M. Burri, referring to the ‘C++ for Particle Physicists' c...

  12. Semiconductor Laser Measurements Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Semiconductor Laser Measurements Laboratory is equipped to investigate and characterize the lasing properties of semiconductor diode lasers. Lasing features such...

  13. 32nd International Conference on the Physics of Semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Chelikowsky, James [Univ. of Texas, Austin, TX (United States)

    2016-10-17

    The International Conference on the Physics of Semiconductors (ICPS) continues a series of biennial conferences that began in the 1950's. ICPS is the premier meeting for reporting all aspects of semiconductor physics including electronic, structural, optical, magnetic and transport properties with an emphasis on new materials and their applications. The meeting will reflect the state of art in the semiconductor physics field and will serve as a forum where scholars, researchers, and specialists can interact to discuss future research directions and technological advancements. The conference typically draws 1,000 international physicists, scientists, and students. This is one of the largest science meetings on semiconductors and related materials to be held in the United States.

  14. A physicist's views on energy problems

    International Nuclear Information System (INIS)

    Revol, Ch.J.P.

    2003-01-01

    The energy problem is one of the most serious challenges facing our civilization. The issue is not whether there are sufficient energy resources in the short- or medium-term, even though world consumption is already considerable, but rather how can we satisfy the world's current and future energy requirements without compromising the planet's ecological balance and how can we ensure an equitable distribution of an acceptable level of energy resources between all countries, including developing countries? The problem has now become a worldwide one with consequences that are also world-wide. The developed countries have lost control of the Earth's ecological future. In 1990 the developing countries consumed only a quarter of the world's energy resources. By 2020 they will already be consuming 60 %. New environmental) friendly technologies will have to be invented to produce sufficient energy at competitive prices. It is not just in the interests of the developed countries to help developing countries to acquire these new technologies, it is also their moral duty to do so. Any injunction to the developing countries not to burn coal and oil as we have done to date would be indefensible. Nuclear energy appears to be one of the possible ways of combating global warming since it produces no CO 2 and is currently the only source or energy capable of meeting demand for several centuries at least. This is the general background to the proposal of Carlo Rubbia and his team of CERN physicists for a new way of exploiting nuclear fission energy which addresses the question: can one imagine fission-based nuclear energy that would be acceptable to our society in other words, an ecological source of nuclear energy? (author)

  15. Lithuanian female physicists: Reality and plans for the future

    Science.gov (United States)

    Šatkovskienė, Dalia; Giriunienė, Ramutė; Ruželė, Živilė; Rutkunienė, Živilė

    2013-03-01

    Changes in the issue of women in physics in Lithuanian in the three years since the 3rd IUPAP International Conference on Women in Physics are discussed on the basis of statistics as well as an exploratory study recently conducted among women physicists. The situation has changed slowly since 2008. However, the study shows that women physicists more clearly understand the inequities and the need for changes, including an active European Union mainstreaming policy targeted to ensure gender equality in the sciences, which gives hope for accelerating changes. Continued plans for improving women physicists' situation in Lithuania are discussed.

  16. Mário Schenberg: Physicist, politician and art critic

    International Nuclear Information System (INIS)

    Guzzo, M. M.; Reggiani, N.

    2015-01-01

    Mário Schenberg is considered one of the greatest theoretical physicists of Brazil. He worked in different fields of physics including thermodynamics, quantum mechanics, statistical mechanics, general relativity, astrophysics and mathematics. He was assistant of the Ukrainian naturalized Italian physicist Gleb Wataghin and worked with prestigious physicists like as the Brazilians José Leite Lopes and César Lattes, the Russian-born American George Gamow and the Indian astrophysicist Subrahmanyan Chandrasekhar. Besides, he was also an active politician and critic of art

  17. Liability from the view of the medical physicist

    International Nuclear Information System (INIS)

    Shalek, R.J.

    1980-01-01

    The negligent performance of professional duties is the most probable type of legal action against a medical physicist. A mistake resulting from ignorance or inadvertence is an example; an error in professional judgement is not negligence if an ordinary, prudent physicist in the same situation would have made the same decision. A physicist or any hospital employee has a duty to protect his employer from liability even to the extent of reporting to the hospital medical practices which could harm the patient. Suggestions for reducing legal risk include recommendations for professional knowledge, record keeping and outside verification of important elements of operating systems

  18. Growth of crystalline semiconductor materials on crystal surfaces

    CERN Document Server

    Aleksandrov, L

    2013-01-01

    Written for physicists, chemists, and engineers specialising in crystal and film growth, semiconductor electronics, and various applications of thin films, this book reviews promising scientific and engineering trends in thin films and thin-films materials science. The first part discusses the physical characteristics of the processes occurring during the deposition and growth of films, the principal methods of obtaining semiconductor films and of reparing substrate surfaces on which crystalline films are grown, and the main applications of films. The second part contains data on epitaxial i

  19. Semiconductor laser shearing interferometer

    International Nuclear Information System (INIS)

    Ming Hai; Li Ming; Chen Nong; Xie Jiaping

    1988-03-01

    The application of semiconductor laser on grating shearing interferometry is studied experimentally in the present paper. The method measuring the coherence of semiconductor laser beam by ion etching double frequency grating is proposed. The experimental result of lens aberration with semiconductor laser shearing interferometer is given. Talbot shearing interferometry of semiconductor laser is also described. (author). 2 refs, 9 figs

  20. French physicist's brother denies links to Al Qaeda

    CERN Multimedia

    Overbye, Dennis

    2009-01-01

    "Days after the French authorities placed a physicist working in Switzerland under formal investigation in a terror case, a portrait of the man and his work has begun to emerge from interviews with officials and his lawyer"

  1. Physicists set new record for network data transfer

    CERN Multimedia

    2007-01-01

    "An international team of physicists, computer scientists, and network engineers joined forces to set new records for sustained data transfer between storage systems durint the SuperComputing 2006 (SC06) Bandwidth Challenge (BWC). (3 pages)

  2. From falling bodies to radiowaves: classical physicists and their discoveries

    International Nuclear Information System (INIS)

    Segre, E.

    1984-01-01

    This chronicle of physics and physicists traces the development of scientific thought from the works of the founding fathers - Galileo, Huggens and Newton - to the more recent discoveries of Maxwell, Boltzmann, and Gibbs

  3. Clinical training of medical physicists. IAEA experience in Asia

    International Nuclear Information System (INIS)

    McLean, D.

    2013-01-01

    Medical physicists make a major contribution to the safe and effective diagnosis and treatment of patients with cancer and other illnesses. The medical physicist's responsibilities include the major areas of dosimetry, treatment planning, quality assurance, image quality, optimization, equipment management, research, teaching, and radiation safety. With the increasing complexity of technological application to medicine the competence of trained physicists is critical to good patient care, with counter examples, sadly evident in the literature. The International Atomic Energy Agency (IAEA), in conjunction with international experts, including from Japan, has developed clinical training programmes that have been successfully implemented on a pilot basis in a number of countries in Asia. A new project is to begin in 2014 which will focus increasingly on the use of electronic teaching material and experiences, to assist medical physicists in clinical training increasingly in more remote locations in Asia. (author)

  4. Rice Physicist to direct $40M LHC Program

    CERN Multimedia

    2006-01-01

    "Rice Universty announced that physicist B. Paul Padley has been chosen to lead the scientific operations for one of the particle detector systems at the European Organization for Nuclear Research's Large Hadron Collider (LHC)."

  5. Education and training of medical physicists in radiology

    International Nuclear Information System (INIS)

    Todorov, V.; Vassileva, J.

    2006-01-01

    Full text: Medical radiology is chronologically the first and widest field of work of medical physicists. Therefore the education and training of medical radiological physicists is of big importance for both diagnostics and therapy. The education of medical radiological physicists in Bulgaria is organized in two levels: university and postgraduate, which is a good achievement of Bulgarian educational system. University education is in the framework of the M. Sc. program in Medical physics with a prevalent training in medical radiological physics. Three universities in the country have been carrying out this education since more than ten years. Postgraduate education covers specialties Medical Radiological Physics and Radiation Hygiene. It is organized by the Medical University but the training is opened also to specialists outside the health care system. The interests in both levels of education and training in Medical Physics is increasing with about 40 trainees in last years. The university and postgraduate education has good quality in theory but still inadequate in practical aspects. The continuous training and qualification of medical physicists has also difficulties; the main reasons are insufficient technical and financial resources as well as the lack of interest of the staff of the training centers. The responsibilities for education and training of medical physicists in radiology should be shared between physicists and physicians in the country

  6. Improving Deterrence of Hard-Core Cartels

    OpenAIRE

    Mariana Tavares de Araujo

    2010-01-01

    Holding perpetrators accountable and tailoring the optimal mix of sanctions through a combination of administrative and criminal penalties are two core elements of Brazil’s anti-cartel enforcement. Mariana Tavares de Araujo (SDE, Brazil)

  7. Semiconductor nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Marstein Erik Stensrud

    2003-07-01

    This thesis presents a study of two material systems containing semiconductor nanocrystals, namely porous silicon (PSi) films and germanium (Ge) nanocrystals embedded in silicon dioxide (SiO2) films. The PSi films were made by anodic etching of silicon (Si) substrates in an electrolyte containing hydrofluoric acid. The PSi films were doped with erbium (Er) using two different doping methods. electrochemical doping and doping by immersing the PSi films in a solution containing Er. The resulting Er concentration profiles were investigated using scanning electron microscopy (SEN1) combined with energy dispersive X-ray analysis (EDS). The main subject of the work on PSi presented in this thesis was investigating and comparing these two doping methods. Ge nanocrystals were made by implanting Ge ions into Si02 films that were subsequently annealed. However. nanocrystal formation occurred only for certain sets of processing parameters. The dependence of the microstructure of the Ge implanted Si02 films on the processing parameters were therefore investigated. A range of methods were employed for these investigations, including transmission electron microscopy (TEM) combined with EDS, X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS). The observed structures, ranging from Ge nanocrystals to voids with diameters of several tens of nanometers and Ge rich Si02 films without any nanocrystals is described. A model explaining the void formation is also presented. For certain sets of processing parameters. An accumulation of Ge at the Si-Si02 interface was observed. The effect of this accumulation on the electrical properties of MOS structures made from Ge implanted SiO2 films was investigated using CV-measurements. (Author)

  8. Fundamentals of semiconductor devices

    CERN Document Server

    Lindmayer, Joseph

    1965-01-01

    Semiconductor properties ; semiconductor junctions or diodes ; transistor fundamentals ; inhomogeneous impurity distributions, drift or graded-base transistors ; high-frequency properties of transistors ; band structure of semiconductors ; high current densities and mechanisms of carrier transport ; transistor transient response and recombination processes ; surfaces, field-effect transistors, and composite junctions ; additional semiconductor characteristics ; additional semiconductor devices and microcircuits ; more metal, insulator, and semiconductor combinations for devices ; four-pole parameters and configuration rotation ; four-poles of combined networks and devices ; equivalent circuits ; the error function and its properties ; Fermi-Dirac statistics ; useful physical constants.

  9. The Status of African American Physicists within the DOE Laboratories

    Science.gov (United States)

    Jackson, Keith

    2005-03-01

    In May 2002 there was a backpage article published in American Physical Society Newsletter by the President of the National Society of Black Physicists (NSBP). This article showed that of the 3372 professional physicists employed at the DOE national labs, only 11 are African American, which on a percentage basis is 4 times less than the total availability of Ph.D. African American physicists in the labor force. NSBP want to provide an update of the interaction between National Society of Black Physicists (NSBP) and the department of Energy in particular the Office of Science on the issue of employment of African American Physicists in scientific and technical. You might ask the following question: Why should the current generation of African American Physicists be concerned about their underepresentation on the scientific staffs of the DOE National Laboratories? The answer to this question may vary from person to person, but I would like to propose the following: The National Laboratories are the largest providers of career opportunities in Physics in the United States. There is a general view in the community; African Americans are not getting a return on their national investment in the DOE National Labs. Failure to engage with HBCU’s through their user facilities causes a training or skills deficit when it comes to preparing students to participate at the forefront of physics research. By rebuffing interactions with HBCU¹s, as many the laboratories have done, the national laboratories are in effect refusing to transfer scientific knowledge to the stakeholders in the African American community. The update will contain some additional information about NSBP proposals to solve the problem of underepresentation of African American and Hispanic physicists within the National Laboratories and how the Office of Science has response these proposals.

  10. TU-F-BRD-01: Biomedical Informatics for Medical Physicists

    International Nuclear Information System (INIS)

    Phillips, M; Kalet, I; McNutt, T; Smith, W

    2014-01-01

    Biomedical informatics encompasses a very large domain of knowledge and applications. This broad and loosely defined field can make it difficult to navigate. Physicists often are called upon to provide informatics services and/or to take part in projects involving principles of the field. The purpose of the presentations in this symposium is to help medical physicists gain some knowledge about the breadth of the field and how, in the current clinical and research environment, they can participate and contribute. Three talks have been designed to give an overview from the perspective of physicists and to provide a more in-depth discussion in two areas. One of the primary purposes, and the main subject of the first talk, is to help physicists achieve a perspective about the range of the topics and concepts that fall under the heading of 'informatics'. The approach is to de-mystify topics and jargon and to help physicists find resources in the field should they need them. The other talks explore two areas of biomedical informatics in more depth. The goal is to highlight two domains of intense current interest--databases and models--in enough depth into current approaches so that an adequate background for independent inquiry is achieved. These two areas will serve as good examples of how physicists, using informatics principles, can contribute to oncology practice and research. Learning Objectives: To understand how the principles of biomedical informatics are used by medical physicists. To put the relevant informatics concepts in perspective with regard to biomedicine in general. To use clinical database design as an example of biomedical informatics. To provide a solid background into the problems and issues of the design and use of data and databases in radiation oncology. To use modeling in the service of decision support systems as an example of modeling methods and data use. To provide a background into how uncertainty in our data and knowledge can be

  11. Clinical Training of Medical Physicists Specializing in Nuclear Medicine

    International Nuclear Information System (INIS)

    2011-01-01

    The application of radiation in human health, for both diagnosis and treatment of disease, is an important component of the work of the IAEA. The responsibility for the increasingly technical aspects of this work is undertaken by the medical physicist. To ensure good practice in this vital area, structured clinical training programmes are required to complement academic learning. This publication is intended to be a guide to the practical implementation of such a programme for nuclear medicine. There is a general and growing awareness that radiation medicine is increasingly dependent on well trained medical physicists who are based in a clinical setting. However an analysis of the availability of medical physicists indicates a large shortfall of qualified and capable professionals. This is particularly evident in developing countries. While strategies to increase educational opportunities are critical to such countries, the need for guidance on structured clinical training was recognized by the members of the Regional Cooperative Agreement for Research, Development and Training related to Nuclear Science and Technology (RCA) for the Asia-Pacific region. Consequently, a technical cooperation regional project (RAS6038) under the RCA programme was formulated to address this need in this region by developing suitable material and establishing its viability. Development of a clinical training guide for medical physicists specialising in nuclear medicine was started in 2009 with the appointment of a core drafting committee of regional and international experts. The publication drew on the experience of clinical training in Australia, Croatia and Sweden and was moderated by physicists working in the Asian region. The present publication follows the approach of earlier IAEA publications in the Training Course Series, specifically Nos 37 and 47, Clinical Training of Medical Physicists Specializing in Radiation Oncology and Clinical Training of Medical Physicists

  12. Accreditation of physicist in radiotherapy-past, present and future

    International Nuclear Information System (INIS)

    Howlett, S.

    2010-01-01

    Full text: Accreditation of medical physicists for clinical radiotherapy practice was commenced by the ACPSEM in 1988 by a group of experienced physicists interested in setting a benchmark of international standard by which to assess practising radiotherapy physicists. It is a voluntary, peer based examination process and leads to the award of Accreditation in Radiotherapy Equipment Commissioning and Quality Assurance (ARECQA). The responsible body within the ACPSEM is the Radiation Oncology Accreditation Panel (ROAP) under the umbrella of the Professional Standards Board(PSB). Over 130 physicists in Australia and New Zealand have been awarded ARECQA and it has been recognised by the radiotherapy professions and government bodies as a desirable and sometimes required, standard of qualification. With the implementation of the Training, Education and Accreditation Program (TEAP) by ACPSEM in 2003, a new Accreditation in Radiation Oncology Medical Physics (AROMP) was established in 2005. ARECQA will cease taking applications from experienced physicists on December 31st 2012 and only the AROMP pathway will be available. An external review of TEAP funded by the Commonwealth Government Department of Health and Ageing (DoHA), which is not yet publicly released, will have implications for AROMP in the future. This talk will review the development and progress of accreditation in radiation oncology medical physics in Australia and New Zealand, its place in the delivery of quality patient care, the relationship to ACPSEM registration, the current situation and future directions. (author)

  13. Solid spectroscopy: semiconductors

    International Nuclear Information System (INIS)

    Silva, C.E.T.G. da

    1983-01-01

    Photoemission as technique of study of the semiconductor electronic structure is shortly discussed. Homogeneous and heterogeneous semiconductors, where volume and surface electronic structure, core levels and O and H chemisorption in GaAs, Schottky barrier are treated, respectively. Amorphous semiconductors are also discussed. (L.C.) [pt

  14. Train medical physicist-urgent need for advanced radiotherapy

    International Nuclear Information System (INIS)

    Hareyama, Masato; Teshima, Teruki; Yamamoto, Tokihiro; Haga, Akihiro; Nakagawa, Keiichi; Uesaka, Mitsuru

    2008-01-01

    A Japanese advanced charged particle therapy for cancer that places fewer physical burdens on patients is leading the world and stereotactic radiotherapy and intensity-modulated radiotherapy (IMRT) have been implemented also as a high precision radiotherapy. For the further advancement and dissemination of the therapy, training and qualification of medical physicists has become more needed. Cancer professional train course plan has been performed at many universities in Japan partly to train medical physicists. This special issue consists of seven relevant articles from experts of academia. Medical physicists have been qualified by the Japan Radiological Society, but should have national qualification such as to carry out the R and D of therapy equipment. This has been supported by many academia such as the Japanese Society for Therapeutic Radiology and Oncology (JASTRO) but not by the Japan Association of Radiological Technologists (JART). (T. Tanaka)

  15. A CERN physicist receives the Gian Carlo Wick Medal

    CERN Multimedia

    2007-01-01

    T.D. Lee, Chairman of the Gian Carlo Wick Medal selection committee, André Martin, the 2007 recipient, and Antonino Zichichi, President of the World Federation of Scientists (WFS)(Copyright : WFS) The 2007 Gian Carlo Wick Gold Medal was presented to the CERN theoretical physicist André Martin in Erice (Italy) on 20 August. The prize is awarded each year by the WFS (World Federation of Scientists), whose president is Professor Antonino Zichichi, to a theoretical physicist for his outstanding contributions to particle physics. The selection committee is composed of eminent physicists and is chaired by the Nobel Physics Prize Laureate, T.D. Lee. André Martin was awarded the Medal in recognition of his work on the total cross-section for interactions between two particles and his contributions to the understanding of heavy quark-antiquark (or quarkonium) systems. In 1965, André Martin established a theoretical basis for the so-call...

  16. What physicists should learn about finance (if they want to)

    Science.gov (United States)

    Schmidt, Anatoly

    2006-03-01

    There has been growing interest among physicists to Econophysics, i.e. analysis and modeling of financial and economic processes using the concepts of theoretical Physics. There has been also perception that the financial industry is a viable alternative for those physicists who are not able or are not willing to pursue career in their major field. However in our times, the Wall Street expects from applicants for quantitative positions not only the knowledge of the stochastic calculus and the methods of time series analysis but also of such concepts as option pricing, portfolio management, and risk measurement. Here I describe a synthetic course based on my book ``Quantitative Finance for Physicists'' (Elsevier, 2004) that outlines both worlds: Econophysics and Mathematical Finance. This course may be offered as elective for senior undergraduate or graduate Physics majors.

  17. Great Physicists - The Life and Times of Leading Physicists from Galileo to Hawking

    Science.gov (United States)

    Cropper, William H.

    2004-09-01

    Here is a lively history of modern physics, as seen through the lives of thirty men and women from the pantheon of physics. William H. Cropper vividly portrays the life and accomplishments of such giants as Galileo and Isaac Newton, Marie Curie and Ernest Rutherford, Albert Einstein and Niels Bohr, right up to contemporary figures such as Richard Feynman, Murray Gell-Mann, and Stephen Hawking. We meet scientists--all geniuses--who could be gregarious, aloof, unpretentious, friendly, dogged, imperious, generous to colleagues or contentious rivals. As Cropper captures their personalities, he also offers vivid portraits of their great moments of discovery, their bitter feuds, their relations with family and friends, their religious beliefs and education. In addition, Cropper has grouped these biographies by discipline--mechanics, thermodynamics, particle physics, and others--each section beginning with a historical overview. Thus in the section on quantum mechanics, readers can see how the work of Max Planck influenced Niels Bohr, and how Bohr in turn influenced Werner Heisenberg. Our understanding of the physical world has increased dramatically in the last four centuries. With Great Physicists , readers can retrace the footsteps of the men and women who led the way.

  18. Nonlinear Spatio-Temporal Dynamics and Chaos in Semiconductors

    Science.gov (United States)

    Schöll, Eckehard

    2005-08-01

    Nonlinear transport phenomena are an increasingly important aspect of modern semiconductor research. This volume deals with complex nonlinear dynamics, pattern formation, and chaotic behavior in such systems. It bridges the gap between two well-established fields: the theory of dynamic systems and nonlinear charge transport in semiconductors. This unified approach helps reveal important electronic transport instabilities. The initial chapters lay a general framework for the theoretical description of nonlinear self-organized spatio-temporal patterns, such as current filaments, field domains, fronts, and analysis of their stability. Later chapters consider important model systems in detail: impact ionization induced impurity breakdown, Hall instabilities, superlattices, and low-dimensional structures. State-of-the-art results include chaos control, spatio-temporal chaos, multistability, pattern selection, activator-inhibitor kinetics, and global coupling, linking fundamental issues to electronic device applications. This book will be of great value to semiconductor physicists and nonlinear scientists alike.

  19. Clinical Training of Medical Physicists Specializing in Diagnostic Radiology

    International Nuclear Information System (INIS)

    2010-01-01

    The application of radiation in human health, for both diagnosis and treatment of disease, is an important component of the work of the IAEA. The responsibility for the increasing technical aspects of this work is undertaken by the medical physicist. To ensure good practice in this vital area, structured clinical training programmes are required to complement academic learning. This publication is intended to be a guide to the practical implementation of such a programme for diagnostic radiology. There is a general and growing awareness that radiation medicine is increasingly dependent on well trained medical physicists based in the clinical setting. However, an analysis of the availability of medical physicists indicates a large shortfall of qualified and capable professionals. This is particularly evident in developing countries. While strategies to increase academic educational opportunities are critical to such countries, the need for guidance on structured clinical training was recognized by the members of the Regional Cooperative Agreement (RCA) for Research, Development and Training related to Nuclear Sciences for Asia and the Pacific. Consequently, a technical cooperation regional project (RAS6038) under the RCA programme was formulated to address this need in the Asia-Pacific region by developing suitable material and establishing its viability. Development of a clinical training guide for medical physicists specializing in diagnostic radiology started in 2007 with the appointment of a core drafting committee of regional and international experts. The publication drew on the experiences of clinical training programmes in Australia and New Zealand, the UK and the USA, and was moderated by physicists working in the Asian region. This publication follows the approach of the IAEA publication Training Course Series No. 37, Clinical Training of Medical Physicists specializing in Radiation Oncology. This approach to clinical training has been successfully tested

  20. Towards a Uniform European Education for Medical Physicists

    International Nuclear Information System (INIS)

    Christofides, S.

    2008-01-01

    The European Federation of Organisations in Medical Physics (EFOMP) mission and objectives are briefly presented. The most attention is given to the education and training activities of the EFOMP. Revised EFOMP recommendations on Education, Training and CPD of Medical Physicists and Policy Statements are listed. In order for Medical Physics to be recognised by the European Union as a profession some future activities like Bologna Declaration process, continuous professional development, European Network for Medical Physics training Schools, actions for the harmonisation of the Education and Training of the Medical Physicist in Europe in accordance with EU Directive 2005/36/EC and EU Recommendation 2008/C 111/01 are also discussed

  1. A day with the women physicists of Pakistan

    Science.gov (United States)

    Hasnain, Aziz Fatima; Islam, Aquila; Ali, Asima; Qureshi, Riffat Mehmood; Qamar, Anisa

    2015-12-01

    The Working Group on Women in Physics successfully organized a national-level meeting of women physicists at the National Centre for Physics, Quaid-e-Azam University, to discuss the agenda for the 5th IUPAP International Conference on Women in Physics. This report describes the outcome of the meeting and the status of female physicists in Pakistan. It also includes a comparative study of the enrollment of women in undergraduate and graduate programs in physics, along with a brief description of factors that create hurdles for female students opting for higher education in this field.

  2. Tasks of physicists and graduated engineers in diagnostic radiology

    International Nuclear Information System (INIS)

    Angerstein, W.

    1987-01-01

    The tasks of physicists and engineers in diagnostic radiology are compiled and trends of development are discussed. Specific duties can be selected from these tasks for each department and physicist individually. An attempt is made to characterize the specific tasks of medical physics. The most important tasks are concerning subjects of (1) investment planning, (2) quality control and quality assurance, (3) service and maintenance, (4) radiation protection and electrical safety, (5) development, testing and adaption of equipment, (6) assistance in running the radiologic department, (7) research, (8) pre- and postgraduate training, (9) educational training, (10) miscellaneous. (author)

  3. Time and ageing: a physicist's look at gerontology

    NARCIS (Netherlands)

    Uffink, J.

    2000-01-01

    To enter, as a physicist, into the field of gerontology brings along certain dangers. I will presumably fall into pitfalls of misunderstanding or step on some other booby traps which those who are familiar with the terrain have learned to avoid. This danger is probably even greater since the

  4. Physicists see golden needle in a micro-cosmic haystack

    CERN Multimedia

    2004-01-01

    An international team of physicists examining an extremely rare form of subatomic particle decay has discovered evidence for the highly sought process, which could be an indication of new forces beyond those incorporated in the Standard Model of particle physics (1 page)

  5. Face to Face Tinker, Builder, Physicist, and Teacher !

    Indian Academy of Sciences (India)

    to science, highlighting the factors and circumstances that guided them in making the career choice to be a scientist. Tinker, Builder, Physicist, and .... Did you feel its influence on your environment in physics? MF: Stanford did want to bring ...

  6. Technical Training Seminar: Physicists in the world of finance

    CERN Multimedia

    Davide Vitè

    2006-01-01

    Monday 27 February TECHNICAL TRAINING SEMINAR from 14:00 to 16:00, Council Chamber (bldg. 503) Physicists in the world of finance Oliver Cooke, Zhengyun Hu / LEHMAN BROTHERS (UK) Two PhD physicists will talk about their experiences of working in investment banking, describing what investment banks do and the jobs which attract physicists and engineers. They will introduce the derivatives markets, and explain the need for advanced modelling. In particular, they will present the many modelling techniques used, including Monte Carlo simulation, solving PDEs, stochastic calculus and data analysis. They will describe a typical day for a physicist in the world of finance, and present a case study in which they will show how they used an idea from physics to solve a finance problem. After a PhD and CERN fellowship on OPAL in the 1990s, Oliver Cooke moved to finance. He was initially a mathematical modeller of derivatives, and now is an exotic derivatives trader at Lehman Brothers in London. He will be j...

  7. Review the Physicists show EVERYTHING happens at the same time

    DEFF Research Database (Denmark)

    javadi, Hossein; Forouzbakhsh, Farshid

    2016-01-01

    Physicist Max Tegmark claims flow of time is illusion. EVERYTHING happens at the same time, Max Tegmark said. [1] To understand how this theory is consistent with the truth, it should be compared with physical previous theories and experiences. The theory is backed up Einstein’s theory...

  8. Review the Physicists show EVERYTHING happens at the same time

    OpenAIRE

    javadi, Hossein; Forouzbakhsh, Farshid

    2016-01-01

    Physicist Max Tegmark claims flow of time is illusion. EVERYTHING happens at the same time, Max Tegmark said. [1] To understand how this theory is consistent with the truth, it should be compared with physical previous theories and experiences. The theory is backed up Einstein’s theory of relativity, Max Tegmark said. [1

  9. German lab unveils plan to build physicists' next collider

    CERN Multimedia

    Abott, A

    2001-01-01

    An international team of physicists are to propose the construction of a major collider. 'TESLA' - the 'Tera electron volt Energy Superconducting Linear Accelerator' will be a linear electron-positron collider based on superconducting resonators. It will be based at DESY and cost around three billion US dollars (2 pages).

  10. Proceedings of the 2. Brazilian Congress of Physicists on Medicine

    International Nuclear Information System (INIS)

    1987-01-01

    The works of the 2. Brazilian Congress of Physicists on Medicine are presented, including course of 'Tomography by Nuclear Magnetic Resonance' and 'New Techniques in the Physics of X Ray Diagnostic' and topics about radiotherapy, radiodiagnostic and dosimetry. (C.G.C.) [pt

  11. Education and training of hospital physicists in Sweden

    International Nuclear Information System (INIS)

    Walstam, R.

    1974-01-01

    The Swedish programme for educating hospital physicists differs from many others by introducing radiation physics at the undergraduate level and requiring an extensive in-service training. In view of the rapid growth of the profession this is considered valuable. The present educational capacity has caused noticeable competition and it is generally necessary to have much higher qualifications than the minimum requirements. (JIW)

  12. "Angels & Demons" May Help Physicists Explain What Matters

    Science.gov (United States)

    Basken, Paul

    2009-01-01

    It's not every day that scientific researchers need to defend themselves against charges of destroying humanity. And yet a group of several dozen physicists associated with the Large Hadron Collider may be getting pretty good at it--and, at the same time, actively engaging in public education and debate in ways that university scientists have…

  13. Proceedings of the school for young high energy physicists

    International Nuclear Information System (INIS)

    McCubbin, N.A.

    1988-01-01

    The paper concerns the Proceedings of the 'School for Young High Energy Physicists', which was held at the Rutherford Appleton Laboratory, Sept. 1987. The lectures were presented in four courses, and were intended to give experimentalists a grounding in Relativistic Quantum Field Theory. The four lectures courses were each selected for INIS and indexed separately. (U.K.)

  14. ENSDF: a nuclear structure data bank for nuclear physicists

    International Nuclear Information System (INIS)

    Blachot, J.

    1987-02-01

    Data Banks have tremendously grown these last years. All the nuclear Structure information are now in the ENSDF. This file is used for the Nuclear Data Sheets publication. The part which contains only Adopted Data could be used as a Data Bank for Nuclear Physicists. Examples of retrevial are given [fr

  15. Physics, Physicists and Revolutionary Capabilities for the Intelligence Community

    Science.gov (United States)

    Porter, Lisa

    2009-05-01

    Over the past several decades, physicists have made seminal contributions to technological capabilities that have enabled the U.S. intelligence community to provide unexpected and unparalleled information to our nation's decision makers and help dispel the cloud of uncertainty they face in dealing with crises and challenges around the world. As we look to the future, we recognize that the ever-quickening pace of changes in the world and the threats we must confront demand continued innovation and improvement in the capabilities needed to provide the information on which our leaders depend. This talk will focus on some of the major technological challenges that the intelligence community faces in the coming years, and the many ways that physicists can help to overcome those challenges. The potential impact of physicists on the future capabilities of the US intelligence community is huge. In addition to the more obvious and direct impact through research in areas ranging from novel sensors to quantum information science, the unique approach physicists bring to a problem can also have an indirect but important effect by influencing how challenges in areas ranging from cybersecurity to advanced analytics are approached and solved. Several examples will be given.

  16. Education and Training of Medical Physicists in Europe

    Directory of Open Access Journals (Sweden)

    P. A. Kaplanis

    2008-01-01

    Full Text Available Introduction: Medical Physicist, as a professional who works in a hospital environment, is a member of a wide clinical team which is responsible for the correct diagnosis and the therapeutic methods applied using radiation. The role of a Medical Physicist is multifold and consists of the estimation of the dose received by patients and personnel, the quality control of radiological equipment, the studies for shielding requirements and the training of several health professionals (doctors, medical physicists, radiologists, technicians, nurses. All the above are prerequisites in order to receive the professional license to act as Medical Physicist.Aim-Research Inquires: The aim of European Union (EU via European Federation of Medical Physics (EFOMP is to apply a common policy among the EU countries in the area of Education and Training in Medical Physics within the context of the current developments in the European Higher Education Area arising from “The Bologna Declaration”. A short-term perspective is the free movement of professionals within EU, via the assurance of knowledge and skills uniformity. A necessary preliminary stage is the collection, classification and further process of relevant information at the European level.Methods-Techniques: To achieve the above in an efficient way EFOMP prepared a questionnaire and sent it to the National Organisation for Medical Physics of each country member of EFOMP (NMO. 23 out of 34 country members responded. The main parts (3 in total of this questionnaire and some typical questions were:Part A: Medical Physics Education•Which degree is required? Is this a university degree? How many years of studies does it represent?•Is there a nationally approved education programme and, if yes, then by whom?•Where do the education and training take place (University, Hospital, or both of them? Are these centers accredited and who gives the accreditation?Part B: Qualified / Specialist Medical Physicist

  17. Compound Semiconductor Radiation Detector

    International Nuclear Information System (INIS)

    Kim, Y. K.; Park, S. H.; Lee, W. G.; Ha, J. H.

    2005-01-01

    In 1945, Van Heerden measured α, β and γ radiations with the cooled AgCl crystal. It was the first radiation measurement using the compound semiconductor detector. Since then the compound semiconductor has been extensively studied as radiation detector. Generally the radiation detector can be divided into the gas detector, the scintillator and the semiconductor detector. The semiconductor detector has good points comparing to other radiation detectors. Since the density of the semiconductor detector is higher than that of the gas detector, the semiconductor detector can be made with the compact size to measure the high energy radiation. In the scintillator, the radiation is measured with the two-step process. That is, the radiation is converted into the photons, which are changed into electrons by a photo-detector, inside the scintillator. However in the semiconductor radiation detector, the radiation is measured only with the one-step process. The electron-hole pairs are generated from the radiation interaction inside the semiconductor detector, and these electrons and charged ions are directly collected to get the signal. The energy resolution of the semiconductor detector is generally better than that of the scintillator. At present, the commonly used semiconductors as the radiation detector are Si and Ge. However, these semiconductor detectors have weak points. That is, one needs thick material to measure the high energy radiation because of the relatively low atomic number of the composite material. In Ge case, the dark current of the detector is large at room temperature because of the small band-gap energy. Recently the compound semiconductor detectors have been extensively studied to overcome these problems. In this paper, we will briefly summarize the recent research topics about the compound semiconductor detector. We will introduce the research activities of our group, too

  18. Clinical Training of Medical Physicists Specializing in Radiation Oncology

    International Nuclear Information System (INIS)

    2009-01-01

    The application of radiation in human health, for both diagnosis and treatment of disease, is an important component of the work of the IAEA. The responsibility for the increasing technical aspects of this work is undertaken by the medical physicist. To ensure good practice in this vital area structured clinical training programmes are required to complement academic learning. This publication is intended to be a guide to the practical implementation of such a programme for radiation therapy. There is a general and growing awareness that radiation medicine is increasingly dependant on well trained medical physicists that are based in the clinical setting. However an analysis of the availability of medical physicists indicates a large shortfall of qualified and capable professionals. This is particularly evident in developing countries. While strategies to increase academic educational opportunities are critical to such countries, the need for guidance on structured clinical training was recognised by the members of the Regional Cooperative Agreement (RCA) for research, development and training related to nuclear sciences for Asia and the Pacific. Consequently a technical cooperation regional project (RAS6038) under the RCA programme was formulated to address this need in the Asia Pacific region by developing suitable material and establishing its viability. Development of a clinical training guide for medical physicists specialising in radiation therapy was started in 2005 with the appointment of a core drafting committee of regional and international experts. Since 2005 the IAEA has convened two additional consultant group meetings including additional experts to prepare the present publication. The publication drew heavily, particularly in the initial stages, from the experience and documents of the Clinical Training Programme for Radiation Oncology Medical Physicists as developed by the Australasian College of Physical Scientists and Engineers in Medicine. Their

  19. The role of the health physicist in nuclear security.

    Science.gov (United States)

    Waller, Edward J; van Maanen, Jim

    2015-04-01

    Health physics is a recognized safety function in the holistic context of the protection of workers, members of the public, and the environment against the hazardous effects of ionizing radiation, often generically designated as radiation protection. The role of the health physicist as protector dates back to the Manhattan Project. Nuclear security is the prevention and detection of, and response to, criminal or intentional unauthorized acts involving or directed at nuclear material, other radioactive material, associated facilities, or associated activities. Its importance has become more visible and pronounced in the post 9/11 environment, and it has a shared purpose with health physics in the context of protection of workers, members of the public, and the environment. However, the duties and responsibilities of the health physicist in the nuclear security domain are neither clearly defined nor recognized, while a fundamental understanding of nuclear phenomena in general, nuclear or other radioactive material specifically, and the potential hazards related to them is required for threat assessment, protection, and risk management. Furthermore, given the unique skills and attributes of professional health physicists, it is argued that the role of the health physicist should encompass all aspects of nuclear security, ranging from input in the development to implementation and execution of an efficient and effective nuclear security regime. As such, health physicists should transcend their current typical role as consultants in nuclear security issues and become fully integrated and recognized experts in the nuclear security domain and decision making process. Issues regarding the security clearances of health physics personnel and the possibility of insider threats must be addressed in the same manner as for other trusted individuals; however, the net gain from recognizing and integrating health physics expertise in all levels of a nuclear security regime far

  20. Semiconductor apparatus and method of fabrication for a semiconductor apparatus

    NARCIS (Netherlands)

    2010-01-01

    The invention relates to a semiconductor apparatus (1) and a method of fabrication for a semiconductor apparatus (1), wherein the semiconductor apparatus (1) comprises a semiconductor layer (2) and a passivation layer (3), arranged on a surface of the semiconductor layer (2), for passivating the

  1. Contacts to semiconductors

    International Nuclear Information System (INIS)

    Tove, P.A.

    1975-08-01

    Contacts to semiconductors play an important role in most semiconductor devices. These devices range from microelectronics to power components, from high-sensitivity light or radiation detectors to light-emitting of microwave-generating components. Silicon is the dominating material but compound semiconductors are increasing in importance. The following survey is an attempt to classify contact properties and the physical mechanisms involved, as well as fabrication methods and methods of investigation. The main interest is in metal-semiconductor type contacts where a few basic concepts are dealt with in some detail. (Auth.)

  2. Semiconductor Electrical Measurements Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Semiconductor Electrical Measurements Laboratory is a research laboratory which complements the Optical Measurements Laboratory. The laboratory provides for Hall...

  3. Niels Bohr. Physicist and philospher of the atomic era

    International Nuclear Information System (INIS)

    Fischer, Ernst Peter

    2012-01-01

    The physicist and Nobel-prize carrier Niels Bohr (1885-1962) changed by his research our view to the world. By his atomic model for the first time the stability of matter could be explained, but simultaneously the atomic physics and nuclear technique based on this made our world so dangerous as never before. In an impressive portrait Ernst Peter Fischer describes the life and action of this fascinating man, his great physical finding, as well as his political engagement.

  4. Uncertain CERN cash means UK physicists face grant freeze.

    CERN Document Server

    1996-01-01

    Britain's funding agency Particle Physics and Astronomy Research Council is uncertain about its ability to cover membership costs to the European Laboratory for Particle Physics (CERN). This has resulted in suspension of research grants to university physicists and astronomers. Funding will be available only for genuine hardship, and for major national and international astronomical projects that have already been sanctioned. The new four-year rolling grants to university-based particle physics group is withheld.

  5. Physicists and Economic Growth: Preparing the Next Generation

    Science.gov (United States)

    Arion, Douglas

    2012-02-01

    For many years it has been recognized that many physicists are ``hidden'' -- deep in the industrial world or holding positions not named ``physicist.'' In parallel with this phenomenon is the recognition that many new and innovative product ideas are, in fact, generated by physicists. There are many more ideas that could be brought to market to the benefit of both society and the inventor, but physicists don't often see themselves as the innovators and inventors that they actually are. A number of education programs have arisen to try to address this issue and to engender a greater entrepreneurial spirit in the scientific community. The ScienceWorks program at Carthage College was one of the first to do so, and has for nearly twenty years prepared undergraduate science majors to understand and practice innovation and value creation. Other programs, such as professional masters degrees, also serve to bridge the technical and business universes. As it is no doubt easier to teach a scientist the world of business than it is to teach a businessperson the world of physics, providing educational experiences in innovation and commercialization to physics students can have tremendous economic impact, and will also better prepare them for whatever career direction they may ultimately pursue, even if it is the traditional tenure-track university position. This talk will discuss education programs that have been effective at preparing physics students for the professional work environment, and some of the positive outcomes that have resulted. Also discussed will be the variety of opportunities and resources that exist for faculty and students to develop the skills, knowledge and abilities to recognize and successfully commercialize innovations.

  6. OBITUARY: Sir William Mitchell Physicist and enthusiast for science

    CERN Multimedia

    Cowley, R

    2002-01-01

    "William Mitchell was successively head of Physics at Reading and Oxford universities, and Chairman of the Science and Engineering Research Council from 1985 to 1990. He is largely responsible for the excellent neutron and X-ray facilities that are available for research by scientists in the UK. He was one of the first to realise that these uniquely powerful facilities would be essential tools not only for physicists but also for chemists, biologists, materials scientists and engineers" (1 page).

  7. The duty health physicist program at Byron Nuclear Power Station

    International Nuclear Information System (INIS)

    Goldsmith, D.G.; Carey, T.R.

    1987-01-01

    The Duty Health Physicist Program at Byron Station was established to deal with routine health physics tasks and provide an interface between frontline and upper radiation-chemistry management. The program consists of a weekly rotation of selected members of the health physics staff into the duty health physicist position to handle the assigned duty tasks. The tasks include, but are not limited to, daily isotopic and air sample review, effluent release package review, maximum permissible concentration calculations, dose approvals, as-low-as-reasonably-achievable action review of pending jobs, and general availability to answer questions and address problems in health-physics-related areas of plant operation. The daily attendance of the duty health physicist at the radiation-chemistry and station plan-of-the-day meetings has increased the overall presence and visibility of the health physics program to upper station management and other station departments. Since its inception in July of 1985, the Duty Health Physics Program has been a major contributor to the observed 50% reduction in reportable personnel errors in the radiation-chemistry department (based on personnel-error-related deviation reports and license event reports generated on the radiation-chemistry department at Byron Station). Although difficulty to quantify, other important benefits of this program are also discussed in this paper

  8. Semiconductors data handbook

    CERN Document Server

    Madelung, Otfried

    2004-01-01

    This volume Semiconductors: Data Handbook contains frequently used data from the corresponding larger Landolt-Börnstein handbooks in a low price book for the individual scientist working in the laboratory. The Handbook contain important information about a large number of semiconductors

  9. Semiconductor radiation detection systems

    CERN Document Server

    2010-01-01

    Covers research in semiconductor detector and integrated circuit design in the context of medical imaging using ionizing radiation. This book explores other applications of semiconductor radiation detection systems in security applications such as luggage scanning, dirty bomb detection and border control.

  10. Spin physics in semiconductors

    CERN Document Server

    Dyakonov, Mikhail I

    2008-01-01

    This book describes beautiful optical and transport phenomena related to the electron and nuclear spins in semiconductors with emphasis on a clear presentation of the physics involved. Recent results on quantum wells and quantum dots are reviewed. The book is intended for students and researchers in the fields of semiconductor physics and nanoelectronics.

  11. Between Industry and Academia: A Physicist's Experiences at The Aerospace Corporation

    Science.gov (United States)

    Camparo, James

    2005-03-01

    The Aerospace Corporation is a nonprofit company whose purposes are exclusively scientific: to provide research, development, and advisory services for space programs that serve the national interest, primarily the Air Force's Space and Missile Systems Center and the National Reconnaissance Office. The corporation's laboratory has a staff of about 150 scientists who conduct research in fields ranging from Space Sciences to Material Sciences and from Analytical Chemistry to Atomic Physics. As a consequence, Aerospace stands midway between an industrial research laboratory, focused on product development, and academic/national laboratories focused on basic science. Drawing from Dr. Camparo's personal experiences, the presentation will discuss advantages and disadvantages of a career at Aerospace, including the role of publishing in peer-reviewed journals and the impact of work on family life. Additionally, the presentation will consider the balance between basic physics, applied physics, and engineering in the work at Aerospace. Since joining Aerospace in 1981, Dr. Camparo has worked as an atomic physicist specializing in the area of atomic clocks, and has had the opportunity to experiment and publish on a broad range of research topics including: the stochastic-field/atom interaction, radiation effects on semiconductor materials, and stellar scintillation.

  12. Compound Semiconductor Radiation Detectors

    CERN Document Server

    Owens, Alan

    2012-01-01

    Although elemental semiconductors such as silicon and germanium are standard for energy dispersive spectroscopy in the laboratory, their use for an increasing range of applications is becoming marginalized by their physical limitations, namely the need for ancillary cooling, their modest stopping powers, and radiation intolerance. Compound semiconductors, on the other hand, encompass such a wide range of physical and electronic properties that they have become viable competitors in a number of applications. Compound Semiconductor Radiation Detectors is a consolidated source of information on all aspects of the use of compound semiconductors for radiation detection and measurement. Serious Competitors to Germanium and Silicon Radiation Detectors Wide-gap compound semiconductors offer the ability to operate in a range of hostile thermal and radiation environments while still maintaining sub-keV spectral resolution at X-ray wavelengths. Narrow-gap materials offer the potential of exceeding the spectral resolutio...

  13. Terahertz semiconductor nonlinear optics

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Hvam, Jørn Märcher; Hoffmann, Matthias

    2013-01-01

    In this proceedings we describe our recent results on semiconductor nonlinear optics, investigated using single-cycle THz pulses. We demonstrate the nonlinear absorption and self-phase modulation of strong-field THz pulses in doped semiconductors, using n-GaAs as a model system. The THz...... nonlinearity in doped semiconductors originates from the near-instantaneous heating of free electrons in the ponderomotive potential created by electric field of the THz pulse, leading to ultrafast increase of electron effective mass by intervalley scattering. Modification of effective mass in turn leads...... to a decrease of plasma frequency in semiconductor and produces a substantial modification of THz-range material dielectric function, described by the Drude model. As a result, the nonlinearity of both absorption coefficient and refractive index of the semiconductor is observed. In particular we demonstrate...

  14. Organic semiconductor crystals.

    Science.gov (United States)

    Wang, Chengliang; Dong, Huanli; Jiang, Lang; Hu, Wenping

    2018-01-22

    Organic semiconductors have attracted a lot of attention since the discovery of highly doped conductive polymers, due to the potential application in field-effect transistors (OFETs), light-emitting diodes (OLEDs) and photovoltaic cells (OPVs). Single crystals of organic semiconductors are particularly intriguing because they are free of grain boundaries and have long-range periodic order as well as minimal traps and defects. Hence, organic semiconductor crystals provide a powerful tool for revealing the intrinsic properties, examining the structure-property relationships, demonstrating the important factors for high performance devices and uncovering fundamental physics in organic semiconductors. This review provides a comprehensive overview of the molecular packing, morphology and charge transport features of organic semiconductor crystals, the control of crystallization for achieving high quality crystals and the device physics in the three main applications. We hope that this comprehensive summary can give a clear picture of the state-of-art status and guide future work in this area.

  15. The current status of education and career paths of students after completion of medical physicist programs in Japan: a survey by the Japanese Board for Medical Physicist Qualification.

    Science.gov (United States)

    Kadoya, Noriyuki; Karasawa, Kumiko; Sumida, Iori; Arimura, Hidetaka; Yamada, Syogo

    2015-07-01

    To standardize educational programs and clinical training for medical physics students, the Japanese Board for Medical Physicist Qualification (JBMP) began to accredit master's, doctorate, and residency programs for medical physicists in 2012. At present, 16 universities accredited by the JBMP offer 22 courses. In this study, we aimed to survey the current status of educational programs and career paths of students after completion of the medical physicist program in Japan. A questionnaire was sent in August 2014 to 32 universities offering medical physicist programs. The questionnaire was created and organized by the educational course certification committee of the JBMP and comprised two sections: the first collected information about the university attended, and the second collected information about characteristics and career paths of students after completion of medical physicist programs from 2008 to 2014. Thirty universities (16 accredited and 14 non-accredited) completed the survey (response rate 94 %). A total of 209, 40, and 3 students graduated from the master's, doctorate, and residency programs, respectively. Undergraduates entered the medical physicist program constantly, indicating an interest in medical physics among undergraduates. A large percentage of the students held a bachelor's degree in radiological technology (master's program 94 %; doctorate program 70 %); graduates obtained a national radiological technologist license. Regarding career paths, although the number of the graduates who work as medical physicist remains low, 7 % with a master's degree and 50 % with a doctorate degree worked as medical physicists. Our results could be helpful for improving the medical physicist program in Japan.

  16. Defects in semiconductors

    International Nuclear Information System (INIS)

    Pimentel, C.A.F.

    1983-01-01

    Some problems openned in the study of defects in semiconductors are presented. In particular, a review is made of the more important problems in Si monocrystals of basic and technological interest: microdefects and the presence of oxigen and carbon. The techniques usually utilized in the semiconductor material characterization are emphatized according its potentialities. Some applications of x-ray techniques in the epitaxial shell characterization in heterostructures, importants in electronic optics, are shown. The increase in the efficiency of these defect analysis methods in semiconductor materials with the use of synchrotron x-ray sources is shown. (L.C.) [pt

  17. Introduction to Semiconductor Devices

    Science.gov (United States)

    Brennan, Kevin F.

    2005-03-01

    This volume offers a solid foundation for understanding the most important devices used in the hottest areas of electronic engineering today, from semiconductor fundamentals to state-of-the-art semiconductor devices in the telecommunications and computing industries. Kevin Brennan describes future approaches to computing hardware and RF power amplifiers, and explains how emerging trends and system demands of computing and telecommunications systems influence the choice, design and operation of semiconductor devices. In addition, he covers MODFETs and MOSFETs, short channel effects, and the challenges faced by continuing miniaturization. His book is both an excellent senior/graduate text and a valuable reference for practicing engineers and researchers.

  18. Spin physics in semiconductors

    CERN Document Server

    2017-01-01

    This book offers an extensive introduction to the extremely rich and intriguing field of spin-related phenomena in semiconductors. In this second edition, all chapters have been updated to include the latest experimental and theoretical research. Furthermore, it covers the entire field: bulk semiconductors, two-dimensional semiconductor structures, quantum dots, optical and electric effects, spin-related effects, electron-nuclei spin interactions, Spin Hall effect, spin torques, etc. Thanks to its self-contained style, the book is ideally suited for graduate students and researchers new to the field.

  19. Physics of semiconductor lasers

    CERN Document Server

    Mroziewicz, B; Nakwaski, W

    2013-01-01

    Written for readers who have some background in solid state physics but do not necessarily possess any knowledge of semiconductor lasers, this book provides a comprehensive and concise account of fundamental semiconductor laser physics, technology and properties. The principles of operation of these lasers are therefore discussed in detail with the interrelations between their design and optical, electrical and thermal properties. The relative merits of a large number of laser structures and their parameters are described to acquaint the reader with the various aspects of the semiconductor l

  20. Semiconductors bonds and bands

    CERN Document Server

    Ferry, David K

    2013-01-01

    As we settle into this second decade of the twenty-first century, it is evident that the advances in micro-electronics have truly revolutionized our day-to-day lifestyle. The technology is built upon semiconductors, materials in which the band gap has been engineered for special values suitable to the particular application. This book, written specifically for a one semester course for graduate students, provides a thorough understanding of the key solid state physics of semiconductors. It describes how quantum mechanics gives semiconductors unique properties that enabled the micro-electronics revolution, and sustain the ever-growing importance of this revolution.

  1. Defects in semiconductors

    CERN Document Server

    Romano, Lucia; Jagadish, Chennupati

    2015-01-01

    This volume, number 91 in the Semiconductor and Semimetals series, focuses on defects in semiconductors. Defects in semiconductors help to explain several phenomena, from diffusion to getter, and to draw theories on materials' behavior in response to electrical or mechanical fields. The volume includes chapters focusing specifically on electron and proton irradiation of silicon, point defects in zinc oxide and gallium nitride, ion implantation defects and shallow junctions in silicon and germanium, and much more. It will help support students and scientists in their experimental and theoret

  2. Solid state physics and physicists of the post war Latvia

    International Nuclear Information System (INIS)

    Zakis, J.

    2003-01-01

    In Latvia during the so-called post war period (1944-1991) fields that promoted the research activities were nuclear research and semiconductor electronics. Being considered as classified the researches in these fields were separated from the universities and transferred to the institutes of recently founded Latvian Academy of Sciences. The institutes related to the so-called sector management ministries performed the most of research in semiconductor physics. Research activities at the University of Latvia were mainly in the basic solid state physics (ionic crystals, Ferro ceramics). Despite of being controlled research activities in solid-state physics in Latvia were on relatively high level recognized both nationally and internationally

  3. Doing physics how physicists take hold of the world

    CERN Document Server

    Krieger, Martin H

    2012-01-01

    Doing Physics makes concepts of physics easier to grasp by relating them to everyday knowledge. Addressing some of the models and metaphors that physicists use to explain the physical world, Martin H. Krieger describes the conceptual world of physics by means of analogies to economics, anthropology, theater, carpentry, mechanisms such as clockworks, and machine tool design. The interaction of elementary particles or chemical species, for example, can be related to the theory of kinship-who can marry whom is like what can interact with what. Likewise, the description of physical situations i

  4. Labor Market Trends for Health Physicists through 2005

    International Nuclear Information System (INIS)

    1997-10-01

    This report reviews past, current, and projected future labor market trends for health physicists through 2005. Information is provided on degrees granted, available supply of new graduates, employment, job openings for new graduates, and salaries. Job openings for new graduates are compared to the available supply of new graduates to assess relative job opportunities in the health physics labor market. The report is divided into three sections: trends during 1983-1993, trends during the mid-1990s, and projected trends for 1997 through 2005

  5. Beller Lecture: Dialogue Across Divides - Physicists and the Iran Dossier

    Science.gov (United States)

    Neuneck, Götz

    For over a decade, the nuclear activities of the Islamic Republic of Iran have been at the center of international concerns and subsequent track II talks. NGOs, think tanks and analysts played a role to help to find technical solutions in a highly political setting. The talk will give an overview about the role of physicists to understand the Iranian sensitive nuclear fuel-cycle and to prepare the ground for the JCPOA. Furthermore, the experience of the work of the Pugwash Conferences on Science and World Affairs will be elaborated.

  6. Julian Schwinger the physicist, the teacher, and the man

    CERN Document Server

    1996-01-01

    In the post-quantum-mechanics era, few physicists, if any, have matched Julian Schwinger in contributions to and influence on the development of physics. A deep and provocative thinker, Schwinger left his indelible mark on all areas of theoretical physics; an eloquent lecturer and immensely successful mentor, he was gentle, intensely private, and known for being "modest about everything except his physics". This book is a collection of talks in memory of him by some of his contemporaries and his former students: A Klein, F Dyson, B DeWitt, W Kohn, D Saxon, P C Martin, K Johnson, S Deser, R Fin

  7. Snowmass 2013 Young Physicists Science and Career Survey Report

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, J. [Fermilab; Asaadi, J. [Syracuse U.; Carls, B. [Fermilab; Cotta, R. [UC, Irvine; Guenette, R. [Yale U.; Kiburg, B. [Fermilab; Kobach, A. [Northwestern U.; Lippincott, H. [Fermilab; Littlejohn, B. [Cincinnati U.; Love, J. [Argonne; Penning, B. [Fermilab; Santos, M. Soares [Fermilab; Strauss, T. [thomas.strauss@lhep.unibe.ch; Szelc, A. [Yale U.; Worcester, E. [Brookhaven; Yu, F. [Fermilab

    2013-07-30

    From April to July 2013 the Snowmass Young Physicists (SYP) administered an online survey collecting the opinions and concerns of the High Energy Physics (HEP) community. The aim of this survey is to provide input into the long term planning meeting known as the Community Summer Study (CSS), or Snowmass on the Mississippi. In total, 1112 respondents took part in the survey including 74 people who had received their training within HEP and have since left for non-academic jobs. This paper presents a summary of the survey results including demographic, career outlook, planned experiments and non-academic career path information collected.

  8. A Physicist in Business: Opportunities, Pitfalls, and Lifestyle.

    Science.gov (United States)

    Woollam, John

    2007-03-01

    A traditional education in physics does not normally include business classes or dealing with opportunities to start a company, yet scientists often now start and run small companies. Physicists are mainly interested in technology. However, other factors quickly dominate chances for business success. These include finance, accounting, cash flow analysis, recruiting, interviewing, personnel issues, marketing, investments, retirement plans, patents and other not always so fun activities. Technical decisions are often strongly influenced by company finances and market-analysis. This talk discusses how to recognize opportunity, how to minimize chances for failure, and lifestyle changes one needs to be aware of before entrepreneurship involvement.

  9. Proceedings of the School for Young High Energy Physicists

    International Nuclear Information System (INIS)

    Barlow, R.J.

    1992-01-01

    The 1991 School for Young High Energy Physicists was attended by 44 first year graduate students - probably the largest number since it was started in 1972. It took place in September, at the Cosener's House, Abingdon, and was organised and funded by Rutherford Appleton Laboratory. Published here are the lectures that were given in the mornings. These were supplemented and reinforced by the work in the afternoons, which were devoted to problems and tutorials. At the end of the intensive two week course the students emerged exhausted, but with a thorough grounding in the Standard Model of Elementary Particle Physics, on which most of them are performing their experimental work. (Author)

  10. A physicists guide to The Los Alamos Primer

    International Nuclear Information System (INIS)

    Reed, B Cameron

    2016-01-01

    In April 1943, a group of scientists at the newly established Los Alamos Laboratory were given a series of lectures by Robert Serber on what was then known of the physics and engineering issues involved in developing fission bombs. Serber’s lectures were recorded in a 24 page report titled The Los Alamos Primer , which was subsequently declassified and published in book form. This paper describes the background to the Primer and analyzes the physics contained in its 22 sections. The motivation for this paper is to provide a firm foundation of the background and contents of the Primer for physicists interested in the Manhattan Project and nuclear weapons. (invited comment)

  11. Managing Inflections in Life and Career: Tale from a Physicist

    Science.gov (United States)

    Bhattacharya, Santanu

    2010-03-01

    By training, a physicist possesses one of the rarest qualities ever imparted in an educational degree program, namely, the ability to take on complex problems, divide them into ``solvable'' parts, derive solutions and put them back as insightful outputs. Dr Bhattacharya, CEO of Salorix, a research, analytics and consulting firm, explains how he has used these skills learned at the graduate school to build a career as a scientist, management consultant and entrepreneur. He will also speak about how the real-life skillsets of understanding and dealing with ``Inflections'', self discovery and introspection can be a great tool for managing one's life and career progression.

  12. Physicists set new record for network data transfer

    CERN Multimedia

    2006-01-01

    "An internatinal team of physicists, computer scientists, and network engineers led by the California Institute of Technology, CERN and the University of Michigan and partners at the University of Florida and Vanderbilt, as well as participants from Brazil (Rio de Janeiro State University, UERJ, and the State Universities of Sao Paulo, USP and UNESP) and Korea (Kyungpook National University, KISTI) joined forces to set new records for sustained data transfer between storage systems during the SuperComputing 2006 (SC06) Bandwidth Challenge (BWC)." (2 pages)

  13. Breast anatomy, physiology and pathology for the physicist

    International Nuclear Information System (INIS)

    Watson, A.B.

    1996-01-01

    Increased awareness of the importance of early breast cancer detection has spurred improvements in mammographic imaging systems and has lead to an ever-increasing role for the medical physicist. This talk will review the anatomy, physiology and pathology of the breast and discuss from a clinician's viewpoint, the proper technical and processing factors required to produce a quality mammographic study. Correct breast positioning for the MLO and CC views, adequate compression, elimination fo motion artifacts, appropriate film density and other important factors that contribute to an optimal diagnostic mammogram will also be examined. (author)

  14. Semiconductor micro cavities: half light, half matter

    International Nuclear Information System (INIS)

    Baumberg, Jeremy J.

    2003-01-01

    Quantum wells sandwiched tightly between two mirrors can be used to make a new type of laser that can amplify light more than any other known material. What do you get if you cross light with matter? It is a question that fascinates today's researchers in quantum optoelectronics, who want to see how far the physical states of the world can be intertwined. Although we have a good understanding of the quantum ingredients of optics and solids - photons and atoms - it turns out that assembling these building blocks in deliberately unfamiliar ways can lead to what is new and often quite unexpected behaviour. Consider 'quantum wells', which form the basis of modern semiconductor lasers. First developed in the 1980s, they lie at the heart of optical-communication and optical-storage technologies such as DVD players and they now have a global market of over 10bn British Pounds. Quantum wells consist of a thin sheet of crystalline semiconductor sandwiched between two sheets of another semiconductor. The outer layers squash the wavefunctions of electrons within the central sheet, increasing the electrons' energy and their interaction with light. Engineers can control the colour of the light emitted by the laser simply by adjusting the energy levels within the central sheet, which acts as a potential well. But this bug-sized playground for electrons has not just had technological ramifications. It has also spawned an enormous variety of new physics, including the quantum Hall effect, which can be used as a fundamental standard for measuring the ratio between the charge on the electron and the Planck constant. Over the last ten years researchers have also become increasingly keen to incorporate quantum wells into what are known as 'semiconductor micro cavities'. Physicists have found that these painstakingly layered materials can be used to create new quantum states that resemble superfluids and can be used in interferometric quantum devices. In the March issue of Physics

  15. Biggest semiconductor installed

    CERN Multimedia

    2008-01-01

    Scientists and technicians at the European Laboratory for Particle Physics, commonly known by its French acronym CERN (Centre Europen pour la Recherche Nuclaire), have completed the installation of the largest semiconductor silicon detector.

  16. Compact semiconductor lasers

    CERN Document Server

    Yu, Siyuan; Lourtioz, Jean-Michel

    2014-01-01

    This book brings together in a single volume a unique contribution by the top experts around the world in the field of compact semiconductor lasers to provide a comprehensive description and analysis of the current status as well as future directions in the field of micro- and nano-scale semiconductor lasers. It is organized according to the various forms of micro- or nano-laser cavity configurations with each chapter discussing key technical issues, including semiconductor carrier recombination processes and optical gain dynamics, photonic confinement behavior and output coupling mechanisms, carrier transport considerations relevant to the injection process, and emission mode control. Required reading for those working in and researching the area of semiconductors lasers and micro-electronics.

  17. Radiation effects in semiconductors

    CERN Document Server

    2011-01-01

    There is a need to understand and combat potential radiation damage problems in semiconductor devices and circuits. Written by international experts, this book explains the effects of radiation on semiconductor devices, radiation detectors, and electronic devices and components. These contributors explore emerging applications, detector technologies, circuit design techniques, new materials, and innovative system approaches. The text focuses on how the technology is being used rather than the mathematical foundations behind it. It covers CMOS radiation-tolerant circuit implementations, CMOS pr

  18. Market survey of semiconductors

    International Nuclear Information System (INIS)

    Mackintosh, I.M.; Diegel, D.; Brown, A.; Brinker, C.S. den

    1977-06-01

    Examination of technology and product trends over the range of current and future products in integrated circuits and optoelectronic displays. Analysis and forecast of major economic influences that affect the production costs of integrated circuits and optoelectronic displays. Forecast of the applications and markets for integrated circuits up to 1985 in West Europe, the USA and Japan. Historic development of the semiconductor industry and the prevailing tendencies - factors which influence success in the semiconductor industry. (orig.) [de

  19. Electronic properties of semiconductor heterostructures

    International Nuclear Information System (INIS)

    Einevoll, G.T.

    1991-02-01

    Ten papers on the electronic properties of semiconductors and semiconductor heterostructures constitute the backbone of this thesis. Four papers address the form and validity of the single-band effective mass approximation for semiconductor heterostructures. In four other papers properties of acceptor states in bulk semiconductors and semiconductor heterostructures are studied using the novel effective bond-orbital model. The last two papers deal with localized excitions. 122 refs

  20. Physicists polish one model while looking to the next

    International Nuclear Information System (INIS)

    Hellemans, A.

    1995-01-01

    High-energy physicists' current explanation for the behavior of subatomic particles and forces, known as the Standard Model, is doing just fine. That was the take-home message for the 800 delegates who gathered here from 27 July to 2 August for the international Europhysics Conference on High-Energy Physics. open-quotes Mainly this was a conference of consolidation, steady progress, many very beautiful and detailed results,close quotes Christopher Llewellyn Smith, director general of CERN, the European particle physics laboratory, told Science. But while a multitude of presentations described ever more accurate tests and confirmations of the model, physicists also discussed hints that a whole new range of phenomena beyond the Standard Model is lurking just above the energies of current accelerators-and within range of the next generation of experiments. Other topics covered in this meeting report include the practical side of detecting and recording events in future particle accelerators and some new information on the elusive neutrino

  1. High energy physicists and graduate students: 1981 census

    International Nuclear Information System (INIS)

    1982-02-01

    This listing of physicists and students associated with the US high energy physics program has been compiled in the Division of High Energy Physics of the Office of Energy Research of the US Department of Energy. This listing has been obtained by asking the research groups, laboratories, and other agencies involved to update previous information. This volume is in two parts. The first part is an alphabetical listing and includes only the name, rank, and institution of high energy physicists and graduate students. The second part of the volume is arranged by institution. Within each institution, the faculty (or permanent staff) and the graduate students are presented in separate alphabetical lists. For each person the entry indicates their birthdate, the year and institution of their highest degree, their rank and institutional affiliation with starting dates, up to three items selected from a list of research specialties, and their sources of federal support. For the graduate students, there is also indicated an estimated date for their degree. Where appropriate, a person is listed at more than one institution. Except as noted in the headings, the information is intended to indicate the situation as of January 1, 1981

  2. High energy physicists and graduate students. 1978 census

    Energy Technology Data Exchange (ETDEWEB)

    None

    1978-11-01

    This listing of physicists and students associated with the U.S. high-energy physics program was obtained by asking the research groups, laboratories, and other agencies involved to update previous information. The first part of this volume is an alphabetical listing and includes only the name, rank, and institution of high-energy physicists and graduate students. The second part of the volume is arranged by institution. Within each institution, the faculty (or permanent staff) and the graduate students are presented in separate alphabetical lists. For each person the entry indicates the year and institution of highest degree, rank and institutional affiliation with starting dates, up to three items selected from a list of research specialties, and sources of federal support. For the graduate students, there is also indicated an estimated date for their degree. Where appropriate, a person is listed at more than one institution. Except as noted in the headings, the information is intended to indicate the situation as of January 1, 1978. (RWR)

  3. High energy physicists and graduate students. 1978 census

    International Nuclear Information System (INIS)

    1978-11-01

    This listing of physicists and students associated with the U.S. high-energy physics program was obtained by asking the research groups, laboratories, and other agencies involved to update previous information. The first part of this volume is an alphabetical listing and includes only the name, rank, and institution of high-energy physicists and graduate students. The second part of the volume is arranged by institution. Within each institution, the faculty (or permanent staff) and the graduate students are presented in separate alphabetical lists. For each person the entry indicates birthdate, the year and institution of highest degree, rank and institutional affiliation with starting dates, up to three items selected from a list of research specialties, and sources of federal support. For the graduate students, there is also indicated an estimated date for their degree. Where appropriate, a person is listed at more than one institution. Except as noted in the headings, the information is intended to indicate the situation as of January 1, 1978

  4. A Physicist's Journey In The Nuclear Power World

    Science.gov (United States)

    Starr, Chauncey

    2000-03-01

    As a participant in the development of civilian nuclear power plants for the past half century, the author presents some of his insights to its history that may be of interest to today's applied physicists. Nuclear power development has involved a mixture of creative vision, science, engineering, and unusual technical, economic, and social obstacles. Nuclear power programs were initiated during the euphoric era of public support for new science immediately following World War II -- a support that lasted almost two decades. Subsequently, nuclear power has had to face a complex mix of public concerns and criticism. The author's involvment in some of these circumstances will be anecdotally described. Although the physics of fission and its byproducts remains at the heart of all nuclear reactor designs, its embodiment in practical energy sources has been shaped by the limitations of engineering primarily and economics secondarily. Very influential has been the continuing interplay with the military's weapons and propulsion programs, and the government's political policies. In this respect, nuclear power's history provides a learning experience that may be applicable to some of the large scale demonstration projects that physicists pursue today.

  5. The Battle for Heavy Water Three physicists' heroic exploits

    CERN Multimedia

    2002-01-01

    Up until the end of the 1970s you could still catch a glimpse of his massive silhouette in the corridors of CERN. Lew Kowarksi, one of the pioneers of the Laboratory, was not only a great physicist; he was also a genuine hero of World War II. In 1940, along with Frédéric Joliot and Hans von Halban, Lew Kowarski managed to get the entire world supply of heavy water away to safety from the Nazis after a fantastic escape from occupied France. At the end of the war, the three physicists played themselves in a film about their adventures entitled 'la Bataille de l'eau lourde'. This film, which has been loaned to us by the French National Film Library, will be shown at CERN for the first time next Thursday. At the beginning of the war, heavy water (D20, two atoms of deuterium and one oxygen atom) was of strategic importance. In 1939 Frédéric Joliot, aided by Hans von Halban and Lew Kowarski, demonstrated the nuclear chain reaction and the moderator role that heavy water plays in it. A few weeks before the inv...

  6. Got Skills? On-the-Job Activities of Physicists

    Science.gov (United States)

    Ivie, Rachel

    2011-03-01

    It goes almost without saying that physics doctorates do a lot more than just physics research or teaching at their jobs. But what exactly do they do? First, I will share basic data showing where physics doctorates are employed. Then I will present data from two of AIP's surveys about the employment of physicists. The first set of data comes from our survey of physics PhDs one year after doctorate. We will consider how often physics doctorates do a variety of activities on the job, including management, technical writing, teamwork, design and development, programming, and advanced mathematics. The second set of data comes from AIP's new survey of PhDs in physics 10 to 13 years after graduation. Data for many of the same activities will be shown for physics doctorates who have been in the workplace about a decade. Depending on the type of job, most industrially employed physics doctorates do some type of physics at work, but they are also very likely to report managing projects, writing for technical audiences, working on a team, and collaborating with non-physicists, among many other activities. This examination of the types of activities physics doctorates perform in the workplace will provide insight on the non-scientific training that would benefit graduate students the most.

  7. You Don't Look Like a Physicist

    Science.gov (United States)

    Santos, Antonio Carlos Fontes

    2017-12-01

    "You don't look like a physicist!" "Sorry, this bus only goes to the university, Sir." "Where are you going, sir?" "So, you are a university professor? But a substitute one, aren't you?" "OK, you're a professor, but do you do research?" As a person of color teaching physics in Brazil, those are some comments that I usually hear. They are consequences of stereotypes, prejudices, and discrimination, which are related but different ideas. Stereotypes indicate expectations and beliefs about an individual or a group, prejudice denotes feelings, and discrimination expresses behaviors. People are likely to be astonished whenever a Black person says that he or she is a physicist. This paper aims to raise awareness of the underrepresentation of Black physics professors and researchers in Brazil and how the lack of quality high school physics education impacts Black and poor students in Brazil. Finally, some considerations on how physics education can assist minority students in overcoming social barriers that contribute to their underrepresentation are presented.

  8. Nuclear forces the making of the physicist Hans Bethe

    CERN Document Server

    Schweber, Silvan S

    2012-01-01

    On the fiftieth anniversary of Hiroshima, Nobel-winning physicist Hans Bethe called on his fellow scientists to stop working on weapons of mass destruction. What drove Bethe, the head of Theoretical Physics at Los Alamos during the Manhattan Project, to renounce the weaponry he had once worked so tirelessly to create? That is one of the questions answered by "Nuclear Forces", a riveting biography of Bethe's early life and development as both a scientist and a man of principle. As Silvan Schweber follows Bethe from his childhood in Germany, to laboratories in Italy and England, and on to Cornell University, he shows how these differing environments were reflected in the kind of physics Bethe produced. Many of the young quantum physicists in the 1930s, including Bethe, had Jewish roots, and Schweber considers how Liberal Judaism in Germany helps explain their remarkable contributions. A portrait emerges of a man whose strategy for staying on top of a deeply hierarchical field was to tackle only those problems h...

  9. Method of doping a semiconductor

    International Nuclear Information System (INIS)

    Yang, C.Y.; Rapp, R.A.

    1983-01-01

    A method is disclosed for doping semiconductor material. An interface is established between a solid electrolyte and a semiconductor to be doped. The electrolyte is chosen to be an ionic conductor of the selected impurity and the semiconductor material and electrolyte are jointly chosen so that any compound formed from the impurity and the semiconductor will have a free energy no lower than the electrolyte. A potential is then established across the interface so as to allow the impurity ions to diffuse into the semiconductor. In one embodiment the semiconductor and electrolyte may be heated so as to increase the diffusion coefficient

  10. Thirty year celebration of the contribution of nuclear medicine physicists in Australia

    International Nuclear Information System (INIS)

    Walker, B. M.

    2007-01-01

    Full text: The intention of this article is to describe the contributions of the many nuclear medicine physicists who in a large or small way have added to the ongoing development of nuclear medicine in Australia from the first years of the discipline in the late 1960s to the present time. Unlike our colleagues in radiation oncology physics, the nuclear medicine physicist fraternity has always been a very small group which unfortunately has not expanded greatly over the 30 years and beyond. This is emphasized in the survey by W.H.Round 1 which showed the bias towards older physicists being involved in the discipline. Because of the small numbers of nuclear medicine physicists in the public hospital system, mostly one or two per teaching hospital, most physicists are heavily involved in clinical duties to keep up the high standard of equipment and software performance required. Many nuclear medicine physicists also have the dual role of hospital radiation safety officers which is becoming more demanding as radiation legislation increases. For this reason much of the pure research has been confined to the hospitals with larger numbers of physicists. However a high proportion of nuclear medicine physicists across the country have contributed greatly to clinical research and development as part of their job. Unfortunately these cannot all be recognised in this article. Young physicists may not realise how much 'in house' research and development was carried out by physicists in the early years of nuclear medicine when equipment companies did not provide the software which is now available to purchase. Many of these innovative techniques and software, described in this article, are still in use today. Some of the 'big events' in the history of nuclear medicine in Australia in which physicists have played a leading role will also be highlighted. This will serve to emphasize how physicists have worked closely with clinicians and technologists in the ongoing development of

  11. Guerrilla science survival strategies of a Cuban physicist

    CERN Document Server

    Altshuler, Ernesto

    2017-01-01

    Full of drama, dedication, and humor, this book narrates the author’s often frustrating experiences working as an experimental physicist in Cuba after the disintegration of the so-called socialist block. Lacking finance and infrastructure, faced with makeshift equipment, unpredictable supplies, and unreliable IT, Altshuler tells how he and his students overcame numerous challenges to make novel and interesting contributions to several fields of science. Along the way, he explains the science - from studies of ant colonies to superconductivity - either qualitatively or quantitatively, but always at a level fully understandable to an undergraduate student of natural sciences or engineering. An even wider audience, however, may skip the technical sections without missing the essence. With numerous anecdotes, photographs and the author’s own delightful cartoons, the book tells a remarkable, and often amusing story of how successful science can be performed against all odds.

  12. The role of medical physicist in radiation protection

    International Nuclear Information System (INIS)

    Nusslin, F.

    2010-01-01

    Ionizing Radiation is applied in Radiation Therapy, Nuclear medicine and Diagnostic Radiology. Radiation Protection in Medical Application of Ionizing Radiation requires specific Professional Competence in all relevant details of the radiation source instrumentation / equipment clinical dosimetry application procedures quality assurance medical risk-benefit assessment. Application in general include Justification of practices (sufficient benefit to the exposed individuals) Limitation of doses to individuals (occupational / public exposure) Optimization of Protection (magnitude and likelihood of exposures, and the number of individuals exposed will be ALARA. Competence of persons is normally assessed by the State by having a formal mechanism for registration, accreditation or certification of medical physicists in the various specialties (e.g. diagnostic radiology, radiation therapy, nuclear medicine). The patient safety in the use of medical radiation will be increased through: Consistent education and certification of medical team members, whose qualifications are recognized nationally, and who follow consensus practice guidelines that meet established national accrediting standards

  13. Review of online educational resources for medical physicists.

    Science.gov (United States)

    Prisciandaro, Joann I

    2013-11-04

    Medical physicists are often involved in the didactic training of graduate students, residents (both physics and physicians), and technologists. As part of continuing medical education, we are also involved in maintenance of certification projects to assist in the education of our peers. As such, it is imperative that we remain current concerning available educational resources. Medical physics journals offer book reviews, allowing us an opportunity to learn about newly published books in the field. A similar means of communication is not currently available for online educational resources. This information is conveyed through informal means. This review presents a summary of online resources available to the medical physics community that may be useful for educational purposes.

  14. Proceedings of the school for young high energy physicists

    International Nuclear Information System (INIS)

    Barlow, R.J.

    1993-04-01

    The 1992 School for young High Energy Physicists took place from September 6-19, at the Cosener's House, Abingdon, and was attended by virtually all United Kingdom 1st year graduate students in the field of Experimental Particle Physics. It was organised and funded by the Rutherford Appleton Laboratory, whose assistance is very gratefully acknowledged. Published here are the lectures that were given in the mornings. These were supplemented and reinforced by the work in the afternoons, which were devoted to problems and tutorials. at the end of the intensive two week course the students emerged exhausted, but with a thorough grounding in the Standard Model of Elementary Particle Physics on which most of them are performing their experimental work. (author)

  15. An introduction to tensors and group theory for physicists

    CERN Document Server

    Jeevanjee, Nadir

    2011-01-01

    An Introduction to Tensors and Group Theory for Physicists provides both an intuitive and rigorous approach to tensors and groups and their role in theoretical physics and applied mathematics. A particular aim is to demystify tensors and provide a unified framework for understanding them in the context of classical and quantum physics. Connecting the component formalism prevalent in physics calculations with the abstract but more conceptual formulation found in many mathematical texts, the work will be a welcome addition to the literature on tensors and group theory. Part I of the text begins with linear algebraic foundations, follows with the modern component-free definition of tensors, and concludes with applications to classical and quantum physics through the use of tensor products. Part II introduces abstract groups along with matrix Lie groups and Lie algebras, then intertwines this material with that of Part I by introducing representation theory. Exercises and examples are provided throughout for go...

  16. Proceedings of the School for Young High Energy Physicists

    International Nuclear Information System (INIS)

    Sedgbeer, J.; Evans, M.E.

    2003-01-01

    Forty-seven experimental particle physicists attended the 2002 Summer School, held, as usual, at The Cosener's House in Abingdon during September. The weather was glorious allowing a number of tutorials and impromptu seminars to take place in the lovely gardens. The lectures were of a high standard and were delivered and received enthusiastically, providing material for lively discussions in tutorials and elsewhere. The students each gave a ten-minute seminar and the general quality of the talks was impressive and the time keeping excellent. The activities described ranged from front-line physics analysis to preparations for the next generation of machines and detectors, and gave a clear indication of the breadth of particle physics activities in the UK

  17. High energy physicists and graduate students. 1985 Census

    International Nuclear Information System (INIS)

    1985-10-01

    An alphabetical listing is given of high energy physicists and graduate students, providing the person's name, rank, and institution. Another listing gives the faculty (or permanent staff) and graduate students for each institution, listing for each person the date of birth, year and institution of highest degree, the rank and institutional affiliation with starting dates, up to three items selected from a list of research specialties, and their sources of federal support. For the graduate students, there is also indicated an estimated date for their degree. Where appropriate, a person may be listed at more than one institution. Except as noted, the information is intended to indicate the situation as of January 1, 1985

  18. Fundamentals of semiconductor lasers

    CERN Document Server

    Numai, Takahiro

    2015-01-01

    This book explains physics under the operating principles of semiconductor lasers in detail based on the experience of the author, dealing with the first manufacturing of phase-shifted DFB-LDs and recent research on transverse modes.   The book also bridges a wide gap between journal papers and textbooks, requiring only an undergraduate-level knowledge of electromagnetism and quantum mechanics, and helps readers to understand journal papers where definitions of some technical terms vary, depending on the paper. Two definitions of the photon density in the rate equations and two definitions of the phase-shift in the phase-shifted DFB-LD are explained, and differences in the calculated results are indicated, depending on the definitions.    Readers can understand the physics of semiconductor lasers and analytical tools for Fabry-Perot LDs, DFB-LDs, and VCSELs and will be stimulated to develop semiconductor lasers themselves.

  19. Coherent dynamics in semiconductors

    DEFF Research Database (Denmark)

    Hvam, Jørn Märcher

    1998-01-01

    enhanced in quantum confined lower-dimensional systems, where exciton and biexciton effects dominate the spectra even at room temperature. The coherent dynamics of excitons are at modest densities well described by the optical Bloch equations and a number of the dynamical effects known from atomic......Ultrafast nonlinear optical spectroscopy is used to study the coherent dynamics of optically excited electron-hole pairs in semiconductors. Coulomb interaction implies that the optical inter-band transitions are dominated, at least at low temperatures, by excitonic effects. They are further...... and molecular systems are found and studied in the exciton-biexciton system of semiconductors. At densities where strong exciton interactions, or many-body effects, become dominant, the semiconductor Bloch equations present a more rigorous treatment of the phenomena Ultrafast degenerate four-wave mixing is used...

  20. Hydrogen in semiconductors II

    CERN Document Server

    Nickel, Norbert H; Weber, Eicke R; Nickel, Norbert H

    1999-01-01

    Since its inception in 1966, the series of numbered volumes known as Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. The "Willardson and Beer" Series, as it is widely known, has succeeded in publishing numerous landmark volumes and chapters. Not only did many of these volumes make an impact at the time of their publication, but they continue to be well-cited years after their original release. Recently, Professor Eicke R. Weber of the University of California at Berkeley joined as a co-editor of the series. Professor Weber, a well-known expert in the field of semiconductor materials, will further contribute to continuing the series' tradition of publishing timely, highly relevant, and long-impacting volumes. Some of the recent volumes, such as Hydrogen in Semiconductors, Imperfections in III/V Materials, Epitaxial Microstructures, High-Speed Heterostructure Devices, Oxygen in Silicon, and others promise that this tradition ...

  1. Photoelectronic properties of semiconductors

    CERN Document Server

    Bube, Richard H

    1992-01-01

    The interaction between light and electrons in semiconductors forms the basis for many interesting and practically significant properties. This book examines the fundamental physics underlying this rich complexity of photoelectronic properties of semiconductors, and will familiarise the reader with the relatively simple models that are useful in describing these fundamentals. The basic physics is also illustrated with typical recent examples of experimental data and observations. Following introductory material on the basic concepts, the book moves on to consider a wide range of phenomena, including photoconductivity, recombination effects, photoelectronic methods of defect analysis, photoeffects at grain boundaries, amorphous semiconductors, photovoltaic effects and photoeffects in quantum wells and superlattices. The author is Professor of Materials Science and Electrical Engineering at Stanford University, and has taught this material for many years. He is an experienced author, his earlier books having fo...

  2. Superconductivity in doped semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Bustarret, E., E-mail: Etienne.bustarret@neel.cnrs.fr

    2015-07-15

    A historical survey of the main normal and superconducting state properties of several semiconductors doped into superconductivity is proposed. This class of materials includes selenides, tellurides, oxides and column-IV semiconductors. Most of the experimental data point to a weak coupling pairing mechanism, probably phonon-mediated in the case of diamond, but probably not in the case of strontium titanate, these being the most intensively studied materials over the last decade. Despite promising theoretical predictions based on a conventional mechanism, the occurrence of critical temperatures significantly higher than 10 K has not been yet verified. However, the class provides an enticing playground for testing theories and devices alike.

  3. Semiconductor opto-electronics

    CERN Document Server

    Moss, TS; Ellis, B

    1972-01-01

    Semiconductor Opto-Electronics focuses on opto-electronics, covering the basic physical phenomena and device behavior that arise from the interaction between electromagnetic radiation and electrons in a solid. The first nine chapters of this book are devoted to theoretical topics, discussing the interaction of electromagnetic waves with solids, dispersion theory and absorption processes, magneto-optical effects, and non-linear phenomena. Theories of photo-effects and photo-detectors are treated in detail, including the theories of radiation generation and the behavior of semiconductor lasers a

  4. Ternary chalcopyrite semiconductors

    CERN Document Server

    Shay, J L; Pamplin, B R

    2013-01-01

    Ternary Chalcopyrite Semiconductors: Growth, Electronic Properties, and Applications covers the developments of work in the I-III-VI2 and II-IV-V2 ternary chalcopyrite compounds. This book is composed of eight chapters that focus on the crystal growth, characterization, and applications of these compounds to optical communications systems. After briefly dealing with the status of ternary chalcopyrite compounds, this book goes on describing the crystal growth of II-IV-V2 and I-III-VI2 single crystals. Chapters 3 and 4 examine the energy band structure of these semiconductor compounds, illustrat

  5. Compound semiconductor device physics

    CERN Document Server

    Tiwari, Sandip

    2013-01-01

    This book provides one of the most rigorous treatments of compound semiconductor device physics yet published. A complete understanding of modern devices requires a working knowledge of low-dimensional physics, the use of statistical methods, and the use of one-, two-, and three-dimensional analytical and numerical analysis techniques. With its systematic and detailed**discussion of these topics, this book is ideal for both the researcher and the student. Although the emphasis of this text is on compound semiconductor devices, many of the principles discussed will also be useful to those inter

  6. Introductory semiconductor device physics

    CERN Document Server

    Parker, Greg

    2004-01-01

    ATOMS AND BONDINGThe Periodic TableIonic BondingCovalent BondingMetallic bondingvan der Waals BondingStart a DatabaseENERGY BANDS AND EFFECTIVE MASSSemiconductors, Insulators and MetalsSemiconductorsInsulatorsMetalsThe Concept of Effective MassCARRIER CONCENTRATIONS IN SEMICONDUCTORSDonors and AcceptorsFermi-LevelCarrier Concentration EquationsDonors and Acceptors Both PresentCONDUCTION IN SEMICONDUCTORSCarrier DriftCarrier MobilitySaturated Drift VelocityMobility Variation with TemperatureA Derivation of Ohm's LawDrift Current EquationsSemiconductor Band Diagrams with an Electric Field Presen

  7. Tunable radiation emitting semiconductor device

    NARCIS (Netherlands)

    2009-01-01

    A tunable radiation emitting semiconductor device includes at least one elongated structure at least partially fabricated from one or more semiconductor materials exhibiting a bandgap characteristic including one or more energy transitions whose energies correspond to photon energies of light

  8. Physical principles of semiconductor detectors

    International Nuclear Information System (INIS)

    Micek, S.L.

    1979-01-01

    The general properties of semiconductors with respect to the possibilities of their use as the ionization radiation detectors are discussed. Some chosen types of semiconductor junctions and their characteristics are briefly presented. There are also discussed the physical phenomena connected with the formation of barriers in various types of semiconductor counters. Finally, the basic properties of three main types of semiconductor detectors are given. (author)

  9. Metal semiconductor contacts and devices

    CERN Document Server

    Cohen, Simon S; Einspruch, Norman G

    1986-01-01

    VLSI Electronics Microstructure Science, Volume 13: Metal-Semiconductor Contacts and Devices presents the physics, technology, and applications of metal-semiconductor barriers in digital integrated circuits. The emphasis is placed on the interplay among the theory, processing, and characterization techniques in the development of practical metal-semiconductor contacts and devices.This volume contains chapters that are devoted to the discussion of the physics of metal-semiconductor interfaces and its basic phenomena; fabrication procedures; and interface characterization techniques, particularl

  10. Handbook of luminescent semiconductor materials

    CERN Document Server

    Bergman, Leah

    2011-01-01

    Photoluminescence spectroscopy is an important approach for examining the optical interactions in semiconductors and optical devices with the goal of gaining insight into material properties. With contributions from researchers at the forefront of this field, Handbook of Luminescent Semiconductor Materials explores the use of this technique to study semiconductor materials in a variety of applications, including solid-state lighting, solar energy conversion, optical devices, and biological imaging. After introducing basic semiconductor theory and photoluminescence principles, the book focuses

  11. MO-E-213-01: Increasing Role of Medical Physicist in Radiation Protection

    International Nuclear Information System (INIS)

    Rehani, M.

    2015-01-01

    The focus of work of medical physicists in 1980’s was on quality control and quality assurance. Radiation safety was important but was dominated by occupational radiation protection. A series of over exposures of patients in radiotherapy, nuclear medicine and observation of skin injuries among patients undergoing interventional procedures in 1990’s started creating the need for focus on patient protection. It gave medical physicists new directions to develop expertise in patient dosimetry and dose management. Publications creating awareness on cancer risks from CT in early part of the current century and over exposures in CT in 2008 brought radiation risks in public domain and created challenging situations for medical physicists. Increasing multiple exposures of individual patient and patient doses of few tens of mSv or exceeding 100 mSv are increasing the role of medical physicists. Expansion of usage of fluoroscopy in the hands of clinical professionals with hardly any training in radiation protection shall require further role for medical physicists. The increasing publications in journals, recent changes in Safety Standards, California law, all increase responsibilities of medical physicists in patient protection. Newer technological developments in dose efficiency and protective devices increase percentage of time devoted by medical physicists on radiation protection activities. Without radiation protection, the roles, responsibilities and day-to-day involvement of medical physicists in diagnostic radiology becomes questionable. In coming years either medical radiation protection may emerge as a specialty or medical physicists will have to keep major part of day-to-day work on radiation protection. Learning Objectives: To understand how radiation protection has been increasing its role in day-to-day activities of medical physicist To be aware about international safety Standards, national and State regulations that require higher attention to radiation

  12. MO-E-213-02: Medical Physicist Involvement in Implementing Patient Protection Standards

    International Nuclear Information System (INIS)

    Seibert, J.

    2015-01-01

    The focus of work of medical physicists in 1980’s was on quality control and quality assurance. Radiation safety was important but was dominated by occupational radiation protection. A series of over exposures of patients in radiotherapy, nuclear medicine and observation of skin injuries among patients undergoing interventional procedures in 1990’s started creating the need for focus on patient protection. It gave medical physicists new directions to develop expertise in patient dosimetry and dose management. Publications creating awareness on cancer risks from CT in early part of the current century and over exposures in CT in 2008 brought radiation risks in public domain and created challenging situations for medical physicists. Increasing multiple exposures of individual patient and patient doses of few tens of mSv or exceeding 100 mSv are increasing the role of medical physicists. Expansion of usage of fluoroscopy in the hands of clinical professionals with hardly any training in radiation protection shall require further role for medical physicists. The increasing publications in journals, recent changes in Safety Standards, California law, all increase responsibilities of medical physicists in patient protection. Newer technological developments in dose efficiency and protective devices increase percentage of time devoted by medical physicists on radiation protection activities. Without radiation protection, the roles, responsibilities and day-to-day involvement of medical physicists in diagnostic radiology becomes questionable. In coming years either medical radiation protection may emerge as a specialty or medical physicists will have to keep major part of day-to-day work on radiation protection. Learning Objectives: To understand how radiation protection has been increasing its role in day-to-day activities of medical physicist To be aware about international safety Standards, national and State regulations that require higher attention to radiation

  13. MO-E-213-02: Medical Physicist Involvement in Implementing Patient Protection Standards

    Energy Technology Data Exchange (ETDEWEB)

    Seibert, J. [UC Davis Medical Center (United States)

    2015-06-15

    The focus of work of medical physicists in 1980’s was on quality control and quality assurance. Radiation safety was important but was dominated by occupational radiation protection. A series of over exposures of patients in radiotherapy, nuclear medicine and observation of skin injuries among patients undergoing interventional procedures in 1990’s started creating the need for focus on patient protection. It gave medical physicists new directions to develop expertise in patient dosimetry and dose management. Publications creating awareness on cancer risks from CT in early part of the current century and over exposures in CT in 2008 brought radiation risks in public domain and created challenging situations for medical physicists. Increasing multiple exposures of individual patient and patient doses of few tens of mSv or exceeding 100 mSv are increasing the role of medical physicists. Expansion of usage of fluoroscopy in the hands of clinical professionals with hardly any training in radiation protection shall require further role for medical physicists. The increasing publications in journals, recent changes in Safety Standards, California law, all increase responsibilities of medical physicists in patient protection. Newer technological developments in dose efficiency and protective devices increase percentage of time devoted by medical physicists on radiation protection activities. Without radiation protection, the roles, responsibilities and day-to-day involvement of medical physicists in diagnostic radiology becomes questionable. In coming years either medical radiation protection may emerge as a specialty or medical physicists will have to keep major part of day-to-day work on radiation protection. Learning Objectives: To understand how radiation protection has been increasing its role in day-to-day activities of medical physicist To be aware about international safety Standards, national and State regulations that require higher attention to radiation

  14. MO-E-213-01: Increasing Role of Medical Physicist in Radiation Protection

    Energy Technology Data Exchange (ETDEWEB)

    Rehani, M. [Massachusetts General Hospital (United States)

    2015-06-15

    The focus of work of medical physicists in 1980’s was on quality control and quality assurance. Radiation safety was important but was dominated by occupational radiation protection. A series of over exposures of patients in radiotherapy, nuclear medicine and observation of skin injuries among patients undergoing interventional procedures in 1990’s started creating the need for focus on patient protection. It gave medical physicists new directions to develop expertise in patient dosimetry and dose management. Publications creating awareness on cancer risks from CT in early part of the current century and over exposures in CT in 2008 brought radiation risks in public domain and created challenging situations for medical physicists. Increasing multiple exposures of individual patient and patient doses of few tens of mSv or exceeding 100 mSv are increasing the role of medical physicists. Expansion of usage of fluoroscopy in the hands of clinical professionals with hardly any training in radiation protection shall require further role for medical physicists. The increasing publications in journals, recent changes in Safety Standards, California law, all increase responsibilities of medical physicists in patient protection. Newer technological developments in dose efficiency and protective devices increase percentage of time devoted by medical physicists on radiation protection activities. Without radiation protection, the roles, responsibilities and day-to-day involvement of medical physicists in diagnostic radiology becomes questionable. In coming years either medical radiation protection may emerge as a specialty or medical physicists will have to keep major part of day-to-day work on radiation protection. Learning Objectives: To understand how radiation protection has been increasing its role in day-to-day activities of medical physicist To be aware about international safety Standards, national and State regulations that require higher attention to radiation

  15. Depletion field focusing in semiconductors

    NARCIS (Netherlands)

    Prins, M.W.J.; Gelder, Van A.P.

    1996-01-01

    We calculate the three-dimensional depletion field profile in a semiconductor, for a planar semiconductor material with a spatially varying potential upon the surface, and for a tip-shaped semiconductor with a constant surface potential. The nonuniform electric field gives rise to focusing or

  16. Nonlinear Elasticity of Doped Semiconductors

    Science.gov (United States)

    2017-02-01

    AFRL-RY-WP-TR-2016-0206 NONLINEAR ELASTICITY OF DOPED SEMICONDUCTORS Mark Dykman and Kirill Moskovtsev Michigan State University...2016 4. TITLE AND SUBTITLE NONLINEAR ELASTICITY OF DOPED SEMICONDUCTORS 5a. CONTRACT NUMBER FA8650-16-1-7600 5b. GRANT NUMBER 5c. PROGRAM...vibration amplitude. 15. SUBJECT TERMS semiconductors , microresonators, microelectromechanical 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF

  17. Semi-conductor rectifiers

    International Nuclear Information System (INIS)

    1981-01-01

    A method is described for treating a semiconductor rectifier, comprising: heating the rectifier to a temperature in the range of 100 0 C to 500 0 C, irradiating the rectifier while maintaining its temperature within the said range, and then annealing the rectifier at a temperature of between 280 0 C and 350 0 C for between two and ten hours. (author)

  18. Semiconductor detector physics

    International Nuclear Information System (INIS)

    Equer, B.

    1987-01-01

    Comprehension of semiconductor detectors follows comprehension of some elements of solid state physics. They are recalled here, limited to the necessary physical principles, that is to say the conductivity. P-n and MIS junctions are discussed in view of their use in detection. Material and structure (MOS, p-n, multilayer, ..) are also reviewed [fr

  19. Is the "glass ceiling" a real problem for women physicists in Argentina?

    Science.gov (United States)

    Frechero, Marisa A.; Amador, Ana; Pastor, Antonio J. Ramirez; Tamarit, Francisco

    2015-12-01

    We evaluate the distribution of female physicists in the Argentinean workforce, analyzing the distribution of women at different levels of education and research using several indicators. Although important imbalances still occur, our findings are encouraging and the distribution of female physicists seems to be changing for the better.

  20. Particle accelerators installed in hospitals: the need for a program of training for medical physicists

    International Nuclear Information System (INIS)

    Brandan, M.E.

    1989-01-01

    This paper was presented at the session which closed the round table. The need for setting up a program of professional training directed by hospital physicists who have functioned for some time as medical physicists in the health centers of the country was proposed. (Author)

  1. The role of the biomedical physicist in the education of the healthcare professions: An EFOMP project

    NARCIS (Netherlands)

    Caruana, C.J.; Wasilewska-Radwanska, M.; Aurengo, A.; Dendy, P.P.; Karenauskaite, V.; Malisan, M.R.; Meijer, J.H.; Mornstein, V.; Rokita, E.; Vano, E.; Wucherer, M.

    2009-01-01

    The role of the biomedical physicist in the education of the healthcare professions has not yet been studied in a systematic manner. This article presents the first results of an EFOMP project aimed at researching and developing this important component of the role of the biomedical physicist. A

  2. Long the fixation of physicists worldwide, a tiny particle is found

    CERN Multimedia

    2006-01-01

    "After decades of intensive effort by both experimental and theoretical physicists worldwide, a tiny particle with no charge, a very low mass and a lifetime much shorter than a nanosecond, dubbed the "axion", has now been detected by the University at Buffalo physicist who first suggested its existence in a little-read paper as early as 194." (2 pages)

  3. MO-A-218-01: CT Protocol Review - Practical Tips for Imaging Physicists.

    Science.gov (United States)

    Pizzutiello, R

    2012-06-01

    In the 1980's and 90's, when every mammography department had a wet film processor and a sundial to keep the schedule, medical physicists performing mammography surveys were primarily focused on measuring machine performance and image quality. As our professional experience matured, medical physicists began to learn that they were uniquely qualified to help to recommend technique factors that would balance dose and image quality. Technique charts using different kVp, target-filter combinations and AEC modes gradually became common and patients benefitted from our input. With the revolutionary change in CT Scanner technology and utilization, medical physicists have begun to contribute their expertise to developing and improving CT protocols. This presentation will present practical challenges and offer some directions for the practicing medical physicist who desires to participate in this critical and emerging aspect of imaging physics practice: CT Protocol Review. © 2012 American Association of Physicists in Medicine.

  4. Physicists develop more powerful tools to combat cancer

    CERN Multimedia

    Antonella Del Rosso and Fabio Capello

    2012-01-01

    The tools physicists are currently sharing with doctors to defeat cancer are high-tech sensors for early detection and particles for use as sharp projectiles. The latest advances in medical physics and some of the most sophisticated devices for imaging, monitoring and treatment were presented at the ICTR-PHE 2012 conference. They will shape the future of advanced healthcare.   @font-face { font-family: "Cambria Math"; }@font-face { font-family: "Cambria"; }p.MsoNormal, li.MsoNormal, div.MsoNormal { margin: 0cm 0cm 0.0001pt; font-size: 12pt; font-family: Cambria; }p.MsoCommentText, li.MsoCommentText, div.MsoCommentText { margin: 0cm 0cm 0.0001pt; font-size: 10pt; font-family: Cambria; }span.MsoCommentReference { }a:link, span.MsoHyperlink { color: blue; text-decoration: underline; }a:visited, span.MsoHyperlinkFollowed { color: purple; text-decoration: underline; }span.CommentTextChar { }.MsoChpDefault { font-size: 10pt; font-family: Cambria; }div.WordSection1 { page: WordSection1; } So...

  5. Dark matter CMB constraints and likelihoods for poor particle physicists

    Energy Technology Data Exchange (ETDEWEB)

    Cline, James M.; Scott, Pat, E-mail: jcline@physics.mcgill.ca, E-mail: patscott@physics.mcgill.ca [Department of Physics, McGill University, 3600 rue University, Montréal, QC, H3A 2T8 (Canada)

    2013-03-01

    The cosmic microwave background provides constraints on the annihilation and decay of light dark matter at redshifts between 100 and 1000, the strength of which depends upon the fraction of energy ending up in the form of electrons and photons. The resulting constraints are usually presented for a limited selection of annihilation and decay channels. Here we provide constraints on the annihilation cross section and decay rate, at discrete values of the dark matter mass m{sub χ}, for all the annihilation and decay channels whose secondary spectra have been computed using PYTHIA in arXiv:1012.4515 (''PPPC 4 DM ID: a poor particle physicist cookbook for dark matter indirect detection''), namely e, μ, τ, V → e, V → μ, V → τ, u, d s, c, b, t, γ, g, W, Z and h. By interpolating in mass, these can be used to find the CMB constraints and likelihood functions from WMAP7 and Planck for a wide range of dark matter models, including those with annihilation or decay into a linear combination of different channels.

  6. Dark matter CMB constraints and likelihoods for poor particle physicists

    International Nuclear Information System (INIS)

    Cline, James M.; Scott, Pat

    2013-01-01

    The cosmic microwave background provides constraints on the annihilation and decay of light dark matter at redshifts between 100 and 1000, the strength of which depends upon the fraction of energy ending up in the form of electrons and photons. The resulting constraints are usually presented for a limited selection of annihilation and decay channels. Here we provide constraints on the annihilation cross section and decay rate, at discrete values of the dark matter mass m χ , for all the annihilation and decay channels whose secondary spectra have been computed using PYTHIA in arXiv:1012.4515 (''PPPC 4 DM ID: a poor particle physicist cookbook for dark matter indirect detection''), namely e, μ, τ, V → e, V → μ, V → τ, u, d s, c, b, t, γ, g, W, Z and h. By interpolating in mass, these can be used to find the CMB constraints and likelihood functions from WMAP7 and Planck for a wide range of dark matter models, including those with annihilation or decay into a linear combination of different channels

  7. The medical physicist in a nuclear medicine department

    International Nuclear Information System (INIS)

    Trujillo Z, F.E.; Gomez A, E.

    2007-01-01

    The diagnostic studies and therapeutic treatments carried out in a Nuclear Medicine department make use of radioactive material. For such a reason it becomes necessary to take a strict control in the reception, use and waste that are generated of the typical works inside the department. Also, work related with the quality control of the equipment dedicated to produce images and of those not image formers, need to carry out to guarantee its maximum performance; as well as quality of the diagnostic and of the therapy imparted in patients. Additionally its are needed to make originated works of the individual procedures to patient and of the acquisition of radioactive materials and removal of the waste or radioactive contaminations. Presently work the recommendations of the American College of Radiology (ACR), the European Federation of Organizations for Medical Physics (EFOMP) and of the Mexican Official Standards relating to the functions that should be observed in a Nuclear Medicine Department are exposed. The ACR and the EFOMP, conclude in their recommendations that the medical physicist fulfills with the suitable profile and likewise they describe in detail the actions and functions that he should supervise, to carry out, to document and to inform. (Author)

  8. A Physicist Role in Innovation within IBM Research

    Science.gov (United States)

    Gallagher, William

    2014-03-01

    The broad and deep insight a physicist brings to the goings on in a large technology company lead to many varied and exciting opportunities. Examples in my own career include contributions to important understanding of new breakthroughs (understanding the basic anisotropy of high temperature superconductivity), bringing vital physics understanding to ambitious engineering projects (basic switching and noise margins in digital Josephson junction technology), and initiating and growing large applied projects based on fundamental physics breakthroughs (magnetoresistive random access memory - MRAM). Success at such undertakings within a large enterprise involves a number of factors. Always seeking out the best expert advice and the best collaborators in unfamiliar technical areas as new ideas develop is enormously helpful and not at all difficult within a large innovative organization. While being imaginative and optimistic, one must also remain brutally honest about the potential value of new endeavors, the hurdles ahead, and the likelihood of success. Always, however, there is no substitute hard work. I can attest that the results of efforts along these directions within a technology company can be very exciting and satisfying, and the process along the way a whole lot of fun.

  9. Discovery Mondays - The particle physicist's best friend: electricity

    CERN Document Server

    2005-01-01

    One of CERN's electrical substations, at Prévessin. Electricity is one of CERN's closest allies. Without it, none of the physicists' extraordinary instruments would work. It is electricity that will guide and accelerate particles around the 27-km ring of the world's most powerful accelerator, the LHC. In the giant magnets inside the experiments electricity is also used to produce a magnetic field 200,000 times greater than the Earth's own magnetic field. Inside the detectors, the resulting magnetic force is used to bend the trajectories of the particles, allowing them to be identified and helping us gain a better understanding of what has happened at the heart of the collisions. Understanding how magnetic fields are produced inside the ATLAS experiment is one of several themes on the programme of the next Discovery Monday. And for a close-up view of operations, we'll also be taking you on a visit to the electricity substation at Meyrin. Come and meet CERN's best friend - electricity. Join us at the Micro...

  10. PET: the importance of physicists for the clinical arena

    CERN Multimedia

    2005-01-01

    David Townsend giving a seminar at CERN on 9 February. The past few years have seen significant advances in the development of instrumentation for Positron Emission Tomography (PET). The recent appearance of combined PET and Computed Tomography (CT) scanners that can simultaneously image both anatomy and function is of particular importance. This was the main subject of "Advances in PET imaging: from physics to physician", a seminar presented at CERN by David Townsend on Wednesday 9 February  and organized by the TT and PH groups. David Townsend, who started his career at CERN in the 1970s, is now Professor at the Department of Medicine, University of Tennessee Medical Center (Knoxville, TN). Recipient of the 2004 Clinical Scientist of the Year Award, he is an internationally renowned researcher and PET physicist, with over 25 years of experience in the field. His 1999 image of the year, an award from the Society of Nuclear Medicine in the US, was produced using a combined state-of-the art PET and a true d...

  11. Becoming a Physicist: How Identities and Practices Shape Physics Trajectories

    Science.gov (United States)

    Quan, Gina M.

    This dissertation studies the relationships and processes which shape students' participation within the discipline of physics. Studying this early disciplinary participation gives insight to how students are supported in or pushed out of physics, which is an important step in cultivating a diverse set of physics students. This research occurs within two learning environments that we co-developed: a physics camp for high school girls and a seminar for undergraduate physics majors to get started in physics research. Using situated learning theory, we conceptualized physics learning to be intertwined with participation in physics practices and identity development. This theoretical perspective draws our attention to relationships between students and the physics community. Specifically, we study how students come to engage in the practices of the community and who they are within the physics community. We find that students' interactions with faculty and peers impact the extent to which students engage in authentic physics practices. These interactions also impact the extent to which students develop identities as physicists. We present implications of these findings for the design of physics learning spaces. Understanding this process of how students become members of the physics community will provide valuable insights into fostering a diverse set of successful trajectories in physics.

  12. Single frequency semiconductor lasers

    CERN Document Server

    Fang, Zujie; Chen, Gaoting; Qu, Ronghui

    2017-01-01

    This book systematically introduces the single frequency semiconductor laser, which is widely used in many vital advanced technologies, such as the laser cooling of atoms and atomic clock, high-precision measurements and spectroscopy, coherent optical communications, and advanced optical sensors. It presents both the fundamentals and characteristics of semiconductor lasers, including basic F-P structure and monolithic integrated structures; interprets laser noises and their measurements; and explains mechanisms and technologies relating to the main aspects of single frequency lasers, including external cavity lasers, frequency stabilization technologies, frequency sweeping, optical phase locked loops, and so on. It paints a clear, physical picture of related technologies and reviews new developments in the field as well. It will be a useful reference to graduate students, researchers, and engineers in the field.

  13. Basic semiconductor physics

    CERN Document Server

    Hamaguchi, Chihiro

    2017-01-01

    This book presents a detailed description of basic semiconductor physics. The text covers a wide range of important phenomena in semiconductors, from the simple to the advanced. Four different methods of energy band calculations in the full band region are explained: local empirical pseudopotential, non-local pseudopotential, KP perturbation and tight-binding methods. The effective mass approximation and electron motion in a periodic potential, Boltzmann transport equation and deformation potentials used for analysis of transport properties are discussed. Further, the book examines experiments and theoretical analyses of cyclotron resonance in detail. Optical and transport properties, magneto-transport, two-dimensional electron gas transport (HEMT and MOSFET) and quantum transport are reviewed, while optical transition, electron-phonon interaction and electron mobility are also addressed. Energy and electronic structure of a quantum dot (artificial atom) are explained with the help of Slater determinants. The...

  14. Semiconductor physics an introduction

    CERN Document Server

    Seeger, Karlheinz

    1999-01-01

    Semiconductor Physics - An Introduction - is suitable for the senior undergraduate or new graduate student majoring in electrical engineering or physics. It will also be useful to solid-state scientists and device engineers involved in semiconductor design and technology. The text provides a lucid account of charge transport, energy transport and optical processes, and a detailed description of many devices. It includes sections on superlattices and quantum well structures, the effects of deep-level impurities on transport, the quantum Hall effect and the calculation of the influence of a magnetic field on the carrier distribution function. This 6th edition has been revised and corrected, and new sections have been added to different chapters.

  15. Three dimensional strained semiconductors

    Science.gov (United States)

    Voss, Lars; Conway, Adam; Nikolic, Rebecca J.; Leao, Cedric Rocha; Shao, Qinghui

    2016-11-08

    In one embodiment, an apparatus includes a three dimensional structure comprising a semiconductor material, and at least one thin film in contact with at least one exterior surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the three dimensional structure. In another embodiment, a method includes forming a three dimensional structure comprising a semiconductor material, and depositing at least one thin film on at least one surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the structure.

  16. Compound semiconductor device modelling

    CERN Document Server

    Miles, Robert

    1993-01-01

    Compound semiconductor devices form the foundation of solid-state microwave and optoelectronic technologies used in many modern communication systems. In common with their low frequency counterparts, these devices are often represented using equivalent circuit models, but it is often necessary to resort to physical models in order to gain insight into the detailed operation of compound semiconductor devices. Many of the earliest physical models were indeed developed to understand the 'unusual' phenomena which occur at high frequencies. Such was the case with the Gunn and IMPATI diodes, which led to an increased interest in using numerical simulation methods. Contemporary devices often have feature sizes so small that they no longer operate within the familiar traditional framework, and hot electron or even quantum­ mechanical models are required. The need for accurate and efficient models suitable for computer aided design has increased with the demand for a wider range of integrated devices for operation at...

  17. Optically coupled semiconductor device

    Energy Technology Data Exchange (ETDEWEB)

    Kumagaya, Naoki

    1988-11-18

    This invention concerns an optically coupled semiconductor device using the light as input signal and a MOS transistor for the output side in order to control on-off of the output side by the input signal which is insulated from the output. Concerning this sort of element, when a MOS transistor and a load resistance are planned to be accumulated on the same chip, a resistor and control of impurity concentration of the channel, etc. become necessary despite that the only formation of a simple P-N junction is enough, for a solar cell, hence cost reduction thereof cannot be done. In order to remove this defect, this invention offers an optically coupled semiconductor device featuring that two solar cells are connected in reverse parallel between the gate sources of the output MOS transistors and an operational light emitting element is individually set facing a respective solar cell. 4 figs.

  18. Doping of organic semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Luessem, B.; Riede, M.; Leo, K. [Institut fuer Angewandte Photophysik, TU Dresden (Germany)

    2013-01-15

    The understanding and applications of organic semiconductors have shown remarkable progress in recent years. This material class has been developed from being a lab curiosity to the basis of first successful products as small organic LED (OLED) displays; other areas of application such as OLED lighting and organic photovoltaics are on the verge of broad commercialization. Organic semiconductors are superior to inorganic ones for low-cost and large-area optoelectronics due to their flexibility, easy deposition, and broad variety, making tailor-made materials possible. However, electrical doping of organic semiconductors, i.e. the controlled adjustment of Fermi level that has been extremely important to the success of inorganic semiconductors, is still in its infancy. This review will discuss recent work on both fundamental principles and applications of doping, focused primarily to doping of evaporated organic layers with molecular dopants. Recently, both p- and n-type molecular dopants have been developed that lead to efficient and stable doping of organic thin films. Due to doping, the conductivity of the doped layers increases several orders of magnitude and allows for quasi-Ohmic contacts between organic layers and metal electrodes. Besides reducing voltage losses, doping thus also gives design freedom in terms of transport layer thickness and electrode choice. The use of doping in applications like OLEDs and organic solar cells is highlighted in this review. Overall, controlled molecular doping can be considered as key enabling technology for many different organic device types that can lead to significant improvements in efficiencies and lifetimes. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Images through semiconductors

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    Improved image processing techniques are constantly being developed for television and for scanners using X-rays or other radiation for industrial or medical applications, etc. As Erik Heijne of CERN explains here, particle physics too has its own special requirements for image processing. The increasing use of semiconductor techniques for handling measurements down to the level of a few microns provides another example of the close interplay between scientific research and technological development. (orig.).

  20. Muonium states in semiconductors

    International Nuclear Information System (INIS)

    Patterson, B.D.

    1987-01-01

    There is a brief summary of what is known about the muonium states isotropic, anisotropic and diamagnetic in diamond and zincblende semiconductors. The report deals with muonium spectroscopy, including the formation probabilities, hyperfine parameters and electronic g-factors of the states. The dynamics of the states is treated including a discussion of the transition from isotropic Mu to anisotropic Mu in diamond, temperature-dependent linewidthes in silicon and germanium and effects of daping and radiation damage

  1. Nonradiative recombination in semiconductors

    CERN Document Server

    Abakumov, VN; Yassievich, IN

    1991-01-01

    In recent years, great progress has been made in the understandingof recombination processes controlling the number of excessfree carriers in semiconductors under nonequilibrium conditions. As a result, it is now possible to give a comprehensivetheoretical description of these processes. The authors haveselected a number of experimental results which elucidate theunderlying physical problems and enable a test of theoreticalmodels. The following topics are dealt with: phenomenological theory ofrecombination, theoretical models of shallow and deep localizedstates, cascade model of carrier captu

  2. Doping of organic semiconductors

    International Nuclear Information System (INIS)

    Luessem, B.; Riede, M.; Leo, K.

    2013-01-01

    The understanding and applications of organic semiconductors have shown remarkable progress in recent years. This material class has been developed from being a lab curiosity to the basis of first successful products as small organic LED (OLED) displays; other areas of application such as OLED lighting and organic photovoltaics are on the verge of broad commercialization. Organic semiconductors are superior to inorganic ones for low-cost and large-area optoelectronics due to their flexibility, easy deposition, and broad variety, making tailor-made materials possible. However, electrical doping of organic semiconductors, i.e. the controlled adjustment of Fermi level that has been extremely important to the success of inorganic semiconductors, is still in its infancy. This review will discuss recent work on both fundamental principles and applications of doping, focused primarily to doping of evaporated organic layers with molecular dopants. Recently, both p- and n-type molecular dopants have been developed that lead to efficient and stable doping of organic thin films. Due to doping, the conductivity of the doped layers increases several orders of magnitude and allows for quasi-Ohmic contacts between organic layers and metal electrodes. Besides reducing voltage losses, doping thus also gives design freedom in terms of transport layer thickness and electrode choice. The use of doping in applications like OLEDs and organic solar cells is highlighted in this review. Overall, controlled molecular doping can be considered as key enabling technology for many different organic device types that can lead to significant improvements in efficiencies and lifetimes. (Copyright copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  3. Isotopically controlled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haller, Eugene E.

    2006-06-19

    The following article is an edited transcript based on the Turnbull Lecture given by Eugene E. Haller at the 2005 Materials Research Society Fall Meeting in Boston on November 29, 2005. The David Turnbull Lectureship is awarded to recognize the career of a scientist who has made outstanding contributions to understanding materials phenomena and properties through research, writing, and lecturing, as exemplified by the life work of David Turnbull. Haller was named the 2005 David Turnbull Lecturer for his 'pioneering achievements and leadership in establishing the field of isotopically engineered semiconductors; for outstanding contributions to materials growth, doping and diffusion; and for excellence in lecturing, writing, and fostering international collaborations'. The scientific interest, increased availability, and technological promise of highly enriched isotopes have led to a sharp rise in the number of experimental and theoretical studies with isotopically controlled semiconductor crystals. This article reviews results obtained with isotopically controlled semiconductor bulk and thin-film heterostructures. Isotopic composition affects several properties such as phonon energies, band structure, and lattice constant in subtle, but, for their physical understanding, significant ways. Large isotope-related effects are observed for thermal conductivity in local vibrational modes of impurities and after neutron transmutation doping. Spectacularly sharp photoluminescence lines have been observed in ultrapure, isotopically enriched silicon crystals. Isotope multilayer structures are especially well suited for simultaneous self- and dopant-diffusion studies. The absence of any chemical, mechanical, or electrical driving forces makes possible the study of an ideal random-walk problem. Isotopically controlled semiconductors may find applications in quantum computing, nanoscience, and spintronics.

  4. Survey of semiconductor physics

    CERN Document Server

    Böer, Karl W

    1992-01-01

    Any book that covers a large variety of subjects and is written by one author lacks by necessity the depth provided by an expert in his or her own field of specialization. This book is no exception. It has been written with the encouragement of my students and colleagues, who felt that an extensive card file I had accumulated over the years of teaching solid state and semiconductor physics would be helpful to more than just a few of us. This file, updated from time to time, contained lecture notes and other entries that were useful in my research and permitted me to give to my students a broader spectrum of information than is available in typical textbooks. When assembling this material into a book, I divided the top­ ics into material dealing with the homogeneous semiconductor, the subject of the previously published Volume 1, and the inhomoge­ neous semiconductor, the subject of this Volume 2. In order to keep the book to a manageable size, sections of tutorial character which can be used as text for a g...

  5. Semiconductor Ion Implanters

    International Nuclear Information System (INIS)

    MacKinnon, Barry A.; Ruffell, John P.

    2011-01-01

    In 1953 the Raytheon CK722 transistor was priced at $7.60. Based upon this, an Intel Xeon Quad Core processor containing 820,000,000 transistors should list at $6.2 billion! Particle accelerator technology plays an important part in the remarkable story of why that Intel product can be purchased today for a few hundred dollars. Most people of the mid twentieth century would be astonished at the ubiquity of semiconductors in the products we now buy and use every day. Though relatively expensive in the nineteen fifties they now exist in a wide range of items from high-end multicore microprocessors like the Intel product to disposable items containing 'only' hundreds or thousands like RFID chips and talking greeting cards. This historical development has been fueled by continuous advancement of the several individual technologies involved in the production of semiconductor devices including Ion Implantation and the charged particle beamlines at the heart of implant machines. In the course of its 40 year development, the worldwide implanter industry has reached annual sales levels around $2B, installed thousands of dedicated machines and directly employs thousands of workers. It represents in all these measures, as much and possibly more than any other industrial application of particle accelerator technology. This presentation discusses the history of implanter development. It touches on some of the people involved and on some of the developmental changes and challenges imposed as the requirements of the semiconductor industry evolved.

  6. The Physics of Semiconductors

    Science.gov (United States)

    Brennan, Kevin F.

    1999-02-01

    Modern fabrication techniques have made it possible to produce semiconductor devices whose dimensions are so small that quantum mechanical effects dominate their behavior. This book describes the key elements of quantum mechanics, statistical mechanics, and solid-state physics that are necessary in understanding these modern semiconductor devices. The author begins with a review of elementary quantum mechanics, and then describes more advanced topics, such as multiple quantum wells. He then disusses equilibrium and nonequilibrium statistical mechanics. Following this introduction, he provides a thorough treatment of solid-state physics, covering electron motion in periodic potentials, electron-phonon interaction, and recombination processes. The final four chapters deal exclusively with real devices, such as semiconductor lasers, photodiodes, flat panel displays, and MOSFETs. The book contains many homework exercises and is suitable as a textbook for electrical engineering, materials science, or physics students taking courses in solid-state device physics. It will also be a valuable reference for practicing engineers in optoelectronics and related areas.

  7. Physicists band together to support a new megaproject

    International Nuclear Information System (INIS)

    Flam, F.

    1993-01-01

    As the Superconducting Super Collider (SSC) flirts with death in the congressional budget process for a second year, another mammoth science project is coming to life. Just a few days after the House voted to kill the $10 billion particle accelerator last month, it approved next year's funding for a megaproject that is a little cheaper and a lot less familiar: a $2.7 billion nuclear reactor known as the Advanced Neutron Source (ANS), to be built at Tennessee's Oak Ridge National Laboratory as a national facility for probing materials with beams of neutrons. The project's success in the House is a sign that physicists can still make a case for big science-at least when the project has a broad scientific constituency and plausible links to national competitiveness. When the facility is completed in 2002, it will be the world's most powerful neutron source, delivering 10 times the flux of neutrons produced by its nearest competitor, at the Institute Lau-Langevin in Grenoble, France. For now, designs call for a reactor about one-tenth the size of a power reactor, says project director West. Fission in the reactor core will send out a steady stream of neutrons. Slowed by heavy water to little more than walking speed, the neutrons will be carried through guides that work like fiber optic cables-by reflecting the neutrons internally, like tennis balls ricocheting down a pipe-to experiments tens or hundreds of meters away. There the neutrons will probe the atomic-scale structure of materials in a way that depends on quantum mechanical quality. Like any subatomic particles, neutrons can be thought of as waves as well as particles. When they bombard matter, their wave nature comes into play. The slow neutrons from the ANS will have a wavelength about equal to the spacing between atoms in a typical solid, making the neutrons especially sensitive to atom-by-atom architecture

  8. A health and safety primer for the practicing health physicist

    International Nuclear Information System (INIS)

    Hylko, J.M.; Bradshaw, M.C.; Ross, L.E.; Brennan, M.J.; Pomatto, C.B.; Shelly, F.C.

    1996-01-01

    Environmental restoration (ER) is the process of removing a facility from service, the demolition of structures the identification and disposal of all hazardous and radioactive wastes, the decontamination of equipment and materials, and the restoration of a site for unrestricted use. The number of ER projects encompassing hazardous, industrial, and radiological conditions is expected to increase in response to various program requirements or mission changes. As a result, the practicing health physicist (HP) may have to address unique health and safety (H and S) issues beyond those of performing routine radiological activities. These unique H and S issues could include, but are not limited to the razing of buildings, the removal of radioactive materials and hazardous chemicals, below-grade excavation, confined space entry, storing flammable or combustible liquids, monitoring exposure to hazardous substances, contacting energized systems (e.g., electricity, hydraulics), noise abatement, the nullification of manufacturer warranties, and the operation and movement of heavy equipment. The purpose of this paper is to educate the practicing HP about these issues by reviewing specific regulations governing all H and S activities, and to provide an example of a site-specific H and S primer (e.g., Health and Safety Plan [HASP]). This primer advices the practicing HP about sound H and S principles, furnishes basic strategies for performing a hazard assessment/job safety analysis (HA/JSA) that can be applied to any ER project, and describes various engineering and administrative controls to mitigate hazardous exposures to ER personnel. In addition, 26 inspection checklist topics are available from the primary author to evaluate the adequacy of the engineering and administrative controls, or to necessitate the use of personal protective equipment (PPE) thereby mitigating the corresponding hazard. (author)

  9. TU-G-213AB-01: Organization and Productivity Strategies for Practicing Medical Physicists.

    Science.gov (United States)

    Jordan, D

    2012-06-01

    Medical physicists face numerous challenges that create stress in the professional workplace. The modern work environment contains multiple communications channels, such as email, smart phones, text and instant messaging, voice mail, pagers, and more. These media make it difficult to organize incoming information, set priorities, and move important work forward in the face of rapid change and the requirement to fulfill multiple responsibilities. Medical physicists in particular are likely to feel acute stress due to off-peak work hour requirements, varied responsibilities including clinical duties, research, teaching, and regulatory matters, and the complexity of supervising other staff members. Many medical physicists also work in multiple physical locations, adding complexity to the task of organizing information and resources. Another common difficulty is that medical physicists' responsibilities typically include some duties that render them subject to frequent and urgent interruption, such as emergency response coverage for radiation safety. The real challenges in the current medical physics work environment differ from those encountered while taking courses and conducting research, as well as from earlier periods when medical physicists faced fewer varied responsibilities, slower-paced change, or both. Today's practicing physicist can benefit greatly from developing a formal framework and skill set to manage their personal workflow. This greatly increases the individual's effectiveness and reduces feelings of stress, while improving the effectiveness of teams or groups in which they participate. In this session, participants will learn about a number of techniques and strategies to manage their own personal workflow. Examples familiar to the medical physicist will be provided to illustrate methods to capture, organize, and act on important information, to delegate effectively, and to handle inevitable interruptions. 1. Describe the use of a personal workflow

  10. Future trends in the supply and demand for radiation oncology physicists.

    Science.gov (United States)

    Mills, Michael D; Thornewill, Judah; Esterhay, Robert J

    2010-04-12

    Significant controversy surrounds the 2012 / 2014 decision announced by the Trustees of the American Board of Radiology (ABR) in October of 2007. According to the ABR, only medical physicists who are graduates of a Commission on Accreditation of Medical Physics Education Programs, Inc. (CAMPEP) accredited academic or residency program will be admitted for examination in the years 2012 and 2013. Only graduates of a CAMPEP accredited residency program will be admitted for examination beginning in the year 2014. An essential question facing the radiation oncology physics community is an estimation of supply and demand for medical physicists through the year 2020. To that end, a Demand & Supply dynamic model was created using STELLA software. Inputs into the model include: a) projected new cancer incidence and prevalence 1990-2020; b) AAPM member ages and retirement projections 1990-2020; c) number of ABR physics diplomates 1990-2009; d) number of patients per Qualified Medical Physicist from Abt Reports I (1995), II (2002) and III (2008); e) non-CAMPEP physicists trained 1990-2009 and projected through 2014; f) CAMPEP physicists trained 1993-2008 and projected through 2014; and g) working Qualified Medical Physicists in radiation oncology in the United States (1990-2007). The model indicates that the number of qualified medical physicists working in radiation oncology required to meet demand in 2020 will be 150-175 per year. Because there is some elasticity in the workforce, a portion of the work effort might be assumed by practicing medical physicists. However, the minimum number of new radiation oncology physicists (ROPs) required for the health of the profession is estimated to be 125 per year in 2020. The radiation oncology physics community should plan to build residency programs to support these numbers for the future of the profession.

  11. TU-E-211-01: Establishing Multidisciplinary Collaboration as a Medical Physicist.

    Science.gov (United States)

    Xing, L; Fraass, B; Ford, E; Chang, S

    2012-06-01

    Many medical physicists are scientists at heart and their career fulfillment includes a balance of clinical service and research development. Multidisciplinary collaboration is a great way for the medical physicists to advance science and technology of our fields and the fields of our collaborators. Cross-pollination among scientists of different fields has been the key for some of the most significant breakthroughs in science and medicine and produced some of the most rewarding experiences for the individuals involved. However, medical physicists face unique challenges in establishing multidisciplinary collaboration because our time and resources for research are often quite limited compared to basic scientists. Yet we medical physicists are uniquely positioned and have a tremendous opportunity to create/contribute to multidisciplinary research: our fields are already multidisciplinary in nature and hospital environment is problem rich. How do we establish and carry out research collaboration with scientists of other fields? How to balance research with your higher priority clinical service? How do you find the right multidisciplinary collaboration in your own environment? We will discuss the challenges, provide real exemplary solutions to the above questions, and offer advise to medical physicists who are interested in starting or improving their multidisciplinary collaboration. There are different kinds of multidisciplinary collaborations a medical physicist can create and participate at different involvement levels. Multidisciplinary collaboration is not for every medical physicist but for those who seek and devote time to it, the experience can be truly rewarding and the impact can be enormous. 1. Learn the types of multidisciplinary collaboration medical physicists can created/participated 2. Learn the approaches and strategies to develop collaborations with scientists and professional of other fields3. Understand the challenges and different approaches to

  12. Roles and Responsibilities, and Education and Training Requirements for Clinically Qualified Medical Physicists (Russian Edition)

    International Nuclear Information System (INIS)

    2014-01-01

    This publication addresses the shortfall of well trained and clinically qualified medical physicists working in radiation medicine. The roles, responsibilities and clinical training requirements of medical physicists have not always been well defined or well understood by health care professionals, health authorities and regulatory agencies. To fill this gap, this publication provides recommendations for the academic education and clinical training of clinically qualified medical physicists, including recommendations for their accreditation certification and registration, along with continuous professional development. The goal is to establish criteria that support the harmonization of education and clinical training worldwide

  13. Electrodes for Semiconductor Gas Sensors

    Science.gov (United States)

    Lee, Sung Pil

    2017-01-01

    The electrodes of semiconductor gas sensors are important in characterizing sensors based on their sensitivity, selectivity, reversibility, response time, and long-term stability. The types and materials of electrodes used for semiconductor gas sensors are analyzed. In addition, the effect of interfacial zones and surface states of electrode–semiconductor interfaces on their characteristics is studied. This study describes that the gas interaction mechanism of the electrode–semiconductor interfaces should take into account the interfacial zone, surface states, image force, and tunneling effect. PMID:28346349

  14. Development of semiconductor electronics

    International Nuclear Information System (INIS)

    Bardeen, John.

    1977-01-01

    In 1931, Wilson applied Block's theory about the energy bands for the motion of electrons in a crystal lattice to semiconductors and showed that conduction can take place in two different ways, by electrons and by holes. Not long afterwards Frenkel showed that these carriers can flow by diffusion in a concentration gradient as well as under the influence of an electric field and wrote down equations for the current flow. The third major contribution, in the late 1930's was the explanation of rectification at a metalsemiconductor contact by Mott and more completely by Schottky. In late 1947 the first transistor of the point contact type was invented by Brattin, Shockley and Bardeen. Then after single crystals of Ge were grown, the junction transistor was developed by the same group. The first silicon transistors appeared in 1954. Then an important step was discovery of the planar transistor by Hoenri in 1960 which led to development of integrated circuits by 1962. Many transistors are produced by batch processing on a slice of silicon. Then in 1965 Mos (Metal-Oxide Semiconductor) transistor and in 1968 LSI (Large Scale Intergration circuits) were developed. Aside from electronic circuits, there are many other applications of semiconductors, including junction power rectifiers, junction luminescence (including lasers), solar batteries, radiation detectors, microwave oscillators and charged-coupled devices for computer memories and devices. One of the latest developments is a microprocessor with thousands of transistors and associated circuitry on a single small chip of silicon. It can be programmed to provide a variety of circuit functions, thus it is not necessary to go through the great expense of LSI's for each desired function, but to use standard microprocessors and program to do the job

  15. Layered semiconductor neutron detectors

    Science.gov (United States)

    Mao, Samuel S; Perry, Dale L

    2013-12-10

    Room temperature operating solid state hand held neutron detectors integrate one or more relatively thin layers of a high neutron interaction cross-section element or materials with semiconductor detectors. The high neutron interaction cross-section element (e.g., Gd, B or Li) or materials comprising at least one high neutron interaction cross-section element can be in the form of unstructured layers or micro- or nano-structured arrays. Such architecture provides high efficiency neutron detector devices by capturing substantially more carriers produced from high energy .alpha.-particles or .gamma.-photons generated by neutron interaction.

  16. Basic properties of semiconductors

    CERN Document Server

    Landsberg, PT

    2013-01-01

    Since Volume 1 was published in 1982, the centres of interest in the basic physics of semiconductors have shifted. Volume 1 was called Band Theory and Transport Properties in the first edition, but the subject has broadened to such an extent that Basic Properties is now a more suitable title. Seven chapters have been rewritten by the original authors. However, twelve chapters are essentially new, with the bulk of this work being devoted to important current topics which give this volume an almost encyclopaedic form. The first three chapters discuss various aspects of modern band theory and the

  17. Electrowetting on semiconductors

    Science.gov (United States)

    Palma, Cesar; Deegan, Robert

    2015-01-01

    Applying a voltage difference between a conductor and a sessile droplet sitting on a thin dielectric film separating it from the conductor will cause the drop to spread. When the conductor is a good metal, the change of the drop's contact angle due to the voltage is given by the Young-Lippmann (YL) equation. Here, we report experiments with lightly doped, single crystal silicon as the conductive electrode. We derive a modified YL equation that includes effects due to the semiconductor and contact line pinning. We show that light induces a non-reversible wetting transition, and that our model agrees well with our experimental results.

  18. Semiconductor ionizino. radiation detectors

    International Nuclear Information System (INIS)

    1982-01-01

    Spectrometric semiconductor detectors of ionizing radiation with the electron-hole junction, based on silicon and germanium are presented. The following parameters are given for the individual types of germanium detectors: energy range of detected radiation, energy resolution given as full width at half maximum (FWHM) and full width at one tenth of maximum (FWTM) for 57 Co and 60 Co, detection sensitivity, optimal voltage, and electric capacitance at optimal voltage. For silicon detectors the value of FWHM for 239 Pu is given, the sensitive area and the depth of the sensitive area. (E.S.)

  19. Band structure of semiconductors

    CERN Document Server

    Tsidilkovski, I M

    2013-01-01

    Band Structure of Semiconductors provides a review of the theoretical and experimental methods of investigating band structure and an analysis of the results of the developments in this field. The book presents the problems, methods, and applications in the study of band structure. Topics on the computational methods of band structure; band structures of important semiconducting materials; behavior of an electron in a perturbed periodic field; effective masses and g-factors for the most commonly encountered band structures; and the treatment of cyclotron resonance, Shubnikov-de Haas oscillatio

  20. The Many Worlds of Leo Szilard: Physicist, Peacemaker, Provocateur

    Science.gov (United States)

    Lanouette, William

    2014-03-01

    Best known for being the first to conceive and patent the nuclear chain reaction in the 1930s, Leo Szilard should also be remembered for other insights in both physics and biology, and for historical initiatives to control the A-bomb he helped create. In physics, Szilard applied entropy to data in a seminal 1929 paper that laid the basis for ``information theory.'' Szilard co-designed an electromagnetic refrigerator pump with Einstein in the 1920s, in 1939 he co-designed the first nuclear reactor with Enrico Fermi, and he later thought up and named the nuclear ``breeder'' reactor. Biologist Francois Jacob called Szilard an ``intellectual bumblebee'' for the many novel ideas he shared, including one that earned Jacob and others the Nobel Prize. James D. Watson said that for intellectual stimulation he liked being around Szilard because ``Leo got excited about something before it was true.'' A political activist, Szilard proposed and drafted the 1939 letter Einstein sent to President Franklin Roosevelt that warned of German A-bomb work and led to the Manhattan Project - where Szilard was ``Chief Physicist.'' Yet Szilard then worked tirelessly to curb nuclear weapons, organizing a scientists' petition to President Truman and lobbying Congress for civilian control of the atom. Szilard loved dreaming up new institutions. He helped to create the Pugwash Conferences on Science and World Affairs, and founded the Council for a Livable World - the first political action committee for arms control. In biology, Szilard proposed the European Molecular Biology Organization modeled on CERN, and helped create the Salk Institute for Biological Studies, where he was one of the first fellows. Shy, witty, and eccentric, Szilard wrote a political satire in 1960 that predicted when the US-Soviet nuclear arms race would end in the late 1980s. Another satire, ``My Trial as a War Criminal'' about scientists' responsibilities for weapons of mass destruction, is credited with prompting

  1. Physicists get first glimpse of antimatter: Stuff of science fiction: Canadian among group making breakthrough

    CERN Multimedia

    Munro, M

    2002-01-01

    "A team of Canadian, U.S. and European physicists, working at the CERN physics facility in Geneva, is reporting in Physical Review Letters this week that it has created and probed atoms of antihydrogen" (1 page).

  2. Black Holes Physicists could soon be creating black holes in the Laboratory

    CERN Multimedia

    Carr, Bernard

    2005-01-01

    Ever sinc physicists invented particle accelerators, nearly 80 years ago, they have used them for such exotic tasks as splitting atoms, transmuting elements, producing antimatter and creating particles not previoulsy observed in nature (7 pages)

  3. The role of physicist in the medical use of radiation and radioisotopes

    International Nuclear Information System (INIS)

    Bose, A.; Eisenlohr, H.

    1977-01-01

    The role of physicists in fields of radiotherapy and radiobiology are brought out in detail. The importance of the physicists in dose measurements, design of equipment and calculations of doses etc. is pointed out. Their responsibility in radiation protection where constant vigilance is necessary and an effort to minimise the dose with maximum benefits to the patient should always be contemplated, is also stressed. (A.K.)

  4. Working with the medical equipment: the status of the medical physicist in Romania today

    International Nuclear Information System (INIS)

    Leanca, Valeria

    2008-01-01

    Full text: The presentation will emphasize on the following points: a) General Information; b) Medical Physics activities in the following fields; c) Role of the medical physicist; d) The National Government Organization and the implementation of the status of the medical physicist working in the hospitals in Romania; e) Organizational Structure; f) Purpose; g) Aims; h) Legislation of Medical Physics; i) Medical equipment in Romania (author)

  5. Single filament semiconductor laser

    International Nuclear Information System (INIS)

    Botez, D.

    1980-01-01

    A semiconductor laser comprising: a body of semiconductor material including a substrate having a surface and a pair of spaced, substantially parallel dove-tailed shaped grooves in said surface, said body having a pair of end surfaces between which said grooves extend, said end surfaces being reflective to light with at least one of said end surfaces being partially transparent to light a first epitaxial layer over said surface of the substrate and the surfaces of the grooves, said first epitaxial layer having a flat surface portion over the portion of the substrate surface between the grooves, a thin second epitaxial layer over said first epitaxial layer, a third epitaxial layer over said second epitaxial layer, said first and third epitaxial layers being of opposite conductivity types and the second epitaxial layer being the active recombination region of the laser with the light being generated therein in the vicinity of the portion which is over the flat surface portion of the first epitaxial layer, and a pair of contacts on said body with one contact being over said third epitaxial body and the other being on said substrate

  6. A Gendered Approach to Science Ethics for US and UK Physicists.

    Science.gov (United States)

    Ecklund, Elaine Howard; Di, Di

    2017-02-01

    Some research indicates that women professionals-when compared to men-may be more ethical in the workplace. Existing literature that discusses gender and ethics is confined to the for-profit business sector and primarily to a US context. In particular, there is little attention paid to gender and ethics in science professions in a global context. This represents a significant gap, as science is a rapidly growing and global professional sector, as well as one with ethically ambiguous areas. Adopting an international comparative perspective, this paper relies on 121 semi-structured interviews with US and UK academic physicists to examine how physicists perceive the impact of gender on science ethics. Findings indicate that some US and UK physicists believe that female scientists handle ethical issues within science in a feminine way whereas their male colleagues approach ethics in a masculine way. Some of these physicists further claim that these different approaches to science ethics lead to male and female scientists' different levels of competitiveness in academic physics. In both the US and the UK, there are "gender-blind" physicists, who do not think gender is related to professional ethics. Relying on physicists' nuanced descriptions this paper contributes to the current understanding of gender and science and engineering ethics.

  7. Electronic structure of semiconductor interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Herman, F

    1983-02-01

    The study of semiconductor interfaces is one of the most active and exciting areas of current semiconductor research. Because interfaces play a vital role in modern semiconductor technology (integrated circuits, heterojunction lasers, solar cells, infrared detectors, etc.), there is a strong incentive to understand interface properties at a fundamental level and advance existing technology thereby. At the same time, technological advances such as molecular beam epitaxy have paved the way for the fabrication of semiconductor heterojunctions and superlattices of novel design which exhibit unusual electronic, optical, and magnetic properties and offer unique opportunities for fundamental scientific research. A general perspective on this subject is offered treating such topics as the atomic and electronic structure of semiconductor surfaces and interfaces; oxidation and oxide layers; semiconductor heterojunctions and superlattices; rectifying metal-semiconductor contacts; and interface reactions. Recent progress is emphasized and some future directions are indicated. In addition, the role that large-scale scientific computation has played in furthering our theoretical understanding of semiconductor surfaces and interfaces is discussed. Finally, the nature of theoretical models, and the role they play in describing the physical world is considered.

  8. Quantum transport in semiconductor nanowires

    NARCIS (Netherlands)

    Van Dam, J.

    2006-01-01

    This thesis describes a series of experiments aimed at understanding the low-temperature electrical transport properties of semiconductor nanowires. The semiconductor nanowires (1-100 nm in diameter) are grown from nanoscale gold particles via a chemical process called vapor-liquid-solid (VLS)

  9. Progress in semiconductor drift detectors

    International Nuclear Information System (INIS)

    Rehak, P.; Walton, J.; Gatti, E.

    1985-01-01

    Progress in testing semiconductor drift detectors is reported. Generally better position and energy resolutions were obtained than resolutions published previously. The improvement is mostly due to new electronics better matched to different detectors. It is shown that semiconductor drift detectors are becoming versatile and reliable detectors for position and energy measurements

  10. Semiconductor materials and their properties

    NARCIS (Netherlands)

    Reinders, Angelina H.M.E.; Verlinden, Pierre; van Sark, Wilfried; Freundlich, Alexandre; Reinders, Angele; Verlinden, Pierre; van Sark, Wilfried; Freundlich, Alexandre

    2017-01-01

    Semiconductor materials are the basic materials which are used in photovoltaic (PV) devices. This chapter introduces solid-state physics and semiconductor properties that are relevant to photovoltaics without spending too much time on unnecessary information. Usually atoms in the group of

  11. Optical coherent control in semiconductors

    DEFF Research Database (Denmark)

    Østergaard, John Erland; Vadim, Lyssenko; Hvam, Jørn Märcher

    2001-01-01

    of quantum control including the recent applications to semiconductors and nanostructures. We study the influence of inhomogeneous broadening in semiconductors on CC results. Photoluminescence (PL) and the coherent emission in four-wave mixing (FWM) is recorded after resonant excitation with phase...

  12. Terahertz Nonlinear Optics in Semiconductors

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Hvam, Jørn Märcher; Hoffmann, Matthias C.

    2013-01-01

    We demonstrate the nonlinear optical effects – selfphase modulation and saturable absorption of a single-cycle THz pulse in a semiconductor. Resulting from THz-induced modulation of Drude plasma, these nonlinear optical effects, in particular, lead to self-shortening and nonlinear spectral...... breathing of a single-cycle THz pulse in a semiconductor....

  13. Electronic structure of semiconductor interfaces

    International Nuclear Information System (INIS)

    Herman, F.

    1983-01-01

    The study of semiconductor interfaces is one of the most active and exciting areas of current semiconductor research. Because interfaces play a vital role in modern semiconductor technology (integrated circuits, heterojunction lasers, solar cells, infrared detectors, etc.), there is a strong incentive to understand interface properties at a fundamental level and advance existing technology thereby. At the same time, technological advances such as molecular beam epitaxy have paved the way for the fabrication of semiconductor heterojunctions and superlattices of novel design which exhibit unusual electronic, optical, and magnetic properties and offer unique opportunities for fundamental scientific research. A general perspective on this subject is offered treating such topics as the atomic and electronic structure of semiconductor surfaces and interfaces; oxidation and oxide layers; semiconductor heterojunctions and superlattices; rectifying metal-semiconductor contacts; and interface reactions. Recent progress is emphasized and some future directions are indicated. In addition, the role that large-scale scientific computation has played in furthering our theoretical understanding of semiconductor surfaces and interfaces is discussed. Finally, the nature of theoretical models, and the role they play in describing the physical world is considered. (Author) [pt

  14. Organic semiconductors in a spin

    CERN Document Server

    Samuel, I

    2002-01-01

    A little palladium can go a long way in polymer-based light-emitting diodes. Inorganic semiconductors such as silicon and gallium arsenide are essential for countless applications in everyday life, ranging from PCs to CD players. However, while they offer unrivalled computational speed, inorganic semiconductors are also rigid and brittle, which means that they are less suited to applications such as displays and flexible electronics. A completely different class of materials - organic semiconductors - are being developed for these applications. Organic semiconductors have many attractive features: they are easy to make, they can emit visible light, and there is tremendous scope for tailoring their properties to specific applications by changing their chemical structure. Research groups and companies around the world have developed a wide range of organic-semiconductor devices, including transistors, light-emitting diodes (LEDs), solar cells and lasers. (U.K.)

  15. PREFACE: 16th Nordic Semiconductor Meeting

    Science.gov (United States)

    Pétur Gíslason, Hafliði; Guðmundsson, Viðar

    1994-01-01

    Some 30 years ago an informal meeting of the few Nordic specialists in semiconductor physics marked the beginning of what has become a biannual meeting of some hundred physicists and physics students from all the Nordic countries. The 16th Nordic Semiconductor Meeting took place at Laugarvatn, Iceland, June 12-15,1994. As a regional meeting the Nordic Semiconductor meeting has three characteristic features all of which distinguish it from more traditional international meetings in the field. First, it has the purpose of promoting Nordic cooperation in the international field of semiconductor physics. Research in the fields of advanced science and technology in the Nordic countries is likely to benefit from joining national forces before participating in the increasing European integration. Second, there is an unusually large fraction of graduate students amongst the participants of the Nordic Semiconductor Meeting. In fact, attending this conference is traditionally a part of the graduate program in seniconductor physics and technology. The Nordic Semiconductor Meeting is often the first conference of international character that graduate students attend in order to present a paper of poster. Third, there is an interdisciplinary quality of the meeting which is normally not the case for meetings of this size. In particular, the number of professional scientists from industry is comparable to the number of their academic colleagues. This is important for both groups, but perhaps the graduate students benefit most from presenting their results to both groups. The 16th Nordic Semiconductor Meeting, the first one in this series held in Iceland, attracted 129 active participants. The scientific programme was divided in twelve oral sessions. A novelty of this meeting was the emphasis on more fundamental physics in one of the two parallel sessions but more applied topics in the other, although the distinction was sometimes a matter of predilection. A poster session

  16. Ion implantation for semiconductors

    International Nuclear Information System (INIS)

    Grey-Morgan, T.

    1995-01-01

    Full text: Over the past two decades, thousands of particle accelerators have been used to implant foreign atoms like boron, phosphorus and arsenic into silicon crystal wafers to produce special embedded layers for manufacturing semiconductor devices. Depending on the device required, the atomic species, the depth of implant and doping levels are the main parameters for the implantation process; the selection and parameter control is totally automated. The depth of the implant, usually less than 1 micron, is determined by the ion energy, which can be varied between 2 and 600 keV. The ion beam is extracted from a Freeman or Bernas type ion source and accelerated to 60 keV before mass analysis. For higher beam energies postacceleration is applied up to 200 keV and even higher energies can be achieved by mass selecting multiplycharged ions, but with a corresponding reduction in beam output. Depending on the device to be manufactured, doping levels can range from 10 10 to 10 15 atoms/cm 2 and are controlled by implanter beam currents in the range up to 30mA; continuous process monitoring ensures uniformity across the wafer of better than 1 % . As semiconductor devices get smaller, additional sophistication is required in the design of the implanter. The silicon wafers charge electrically during implantation and this charge must be dissipated continuously to reduce the electrical stress in the device and avoid destructive electrical breakdown. Electron flood guns produce low energy electrons (below 10 electronvolts) to neutralize positive charge buildup and implanter design must ensure minimum contamination by other isotopic species and ensure low internal sputter rates. The pace of technology in the semiconductor industry is such that implanters are being built now for 256 Megabit circuits but which are only likely to be widely available five years from now. Several specialist companies manufacture implanter systems, each costing around US$5 million, depending on the

  17. Semiconductor radiation detector

    Science.gov (United States)

    Bell, Zane W.; Burger, Arnold

    2010-03-30

    A semiconductor detector for ionizing electromagnetic radiation, neutrons, and energetic charged particles. The detecting element is comprised of a compound having the composition I-III-VI.sub.2 or II-IV-V.sub.2 where the "I" component is from column 1A or 1B of the periodic table, the "II" component is from column 2B, the "III" component is from column 3A, the "IV" component is from column 4A, the "V" component is from column 5A, and the "VI" component is from column 6A. The detecting element detects ionizing radiation by generating a signal proportional to the energy deposited in the element, and detects neutrons by virtue of the ionizing radiation emitted by one or more of the constituent materials subsequent to capture. The detector may contain more than one neutron-sensitive component.

  18. Semiconductor testing method

    International Nuclear Information System (INIS)

    Brown, Stephen.

    1992-01-01

    In a method of avoiding use of nuclear radiation, eg gamma rays, X-rays, electron beams, for testing semiconductor components for resistance to hard radiation, which hard radiation causes data corruption in some memory devices and 'latch-up' in others, similar fault effects can be achieved using a xenon or other 'light' flash gun even though the penetration of light is significantly less than that of gamma rays. The method involves treating a device with gamma radiation, measuring a particular fault current at the onset of a fault event, repeating the test with light to confirm the occurrence of the fault event at the same measured fault current, and using the fault current value as a reference for future tests using light on similar devices. (author)

  19. Radial semiconductor drift chambers

    International Nuclear Information System (INIS)

    Rawlings, K.J.

    1987-01-01

    The conditions under which the energy resolution of a radial semiconductor drift chamber based detector system becomes dominated by the step noise from the detector dark current have been investigated. To minimise the drift chamber dark current attention should be paid to carrier generation at Si/SiO 2 interfaces. This consideration conflicts with the desire to reduce the signal risetime: a higher drift field for shorter signal pulses requires a larger area of SiO 2 . Calculations for the single shaping and pseudo Gaussian passive filters indicate that for the same degree of signal risetime sensitivity in a system dominated by the step noise from the detector dark current, the pseudo Gaussian filter gives only a 3% improvement in signal/noise and 12% improvement in rate capability compared with the single shaper performance. (orig.)

  20. Energy distribution in semiconductors

    International Nuclear Information System (INIS)

    Ance, C.

    1979-01-01

    For various semiconductors the dispersive energy Esub(d) defined in the Wemple-Didomenico model is connected with the covalent and ionic energies Esub(h) and C. A continuous curve of ionicity against the ratio of the two energies Esub(A) and Esub(B), connected to Esub(h) and C is reported. Afromowitz's model is applied to the ternary compounds Gasub(1-x)Alsub(x)Sb using optical decomposition. From these results the average energy gap Esub(g) is given by Esub(g) = D 0 M 0 sup((IB))/(epsilon 1 (0)-1) where M 0 sup((IB)) is the interband transition contribution to the optical moment M 0 . (author)

  1. Organic Semiconductor Photovoltaics

    Science.gov (United States)

    Sariciftci, Niyazi Serdar

    2005-03-01

    Recent developments on organic photovoltaic elements are reviewed. Semiconducting conjugated polymers and molecules as well as nanocrystalline inorganic semiconductors are used in composite thin films. The photophysics of such photoactive devices is based on the photoinduced charge transfer from donor type semiconducting molecules onto acceptor type molecules such as Buckminsterfullerene, C60 and/or nanoparticles. Similar to the first steps in natural photosynthesis, this photoinduced electron transfer leads to a number of potentially interesting applications which include sensitization of the photoconductivity and photovoltaic phenomena. Examples of photovoltaic architectures are discussed with their potential in terrestrial solar energy conversion. Several materials are introduced and discussed for their photovoltaic activities. Furthermore, nanomorphology has been investigated with AFM, SEM and TEM. The morphology/property relationship for a given photoactive system is found to be a major effect.

  2. Hard Core Pharmacology: How Much Is Taught in Pharmacy Schools?

    Science.gov (United States)

    Bachmann, Kenneth A.; And Others

    1990-01-01

    A survey was sent to eighty-five American Association of Colleges of Pharmacy-member schools and affiliates to learn how many lectures are accorded to core sequences in pharmacology. The data were intended to provide a frame of reference for the University of Toledo College of Pharmacy. (Author/MLW)

  3. Equilibration: Developing the Hard Core of the Piagetian Research Program.

    Science.gov (United States)

    Rowell, J.A.

    1983-01-01

    Argues that the status of the concept of equilibration is classified by considering Piagetian theory as a research program in the sense elaborated in 1974 by Lakatos. A pilot study was made to examine the precision and testability of equilibration in Piaget's 1977 model.(Author/RH)

  4. Educational outcomes of a medical physicist program over the past 10 years in Japan

    International Nuclear Information System (INIS)

    Kadoya, Noriyuki; Karasawa, Kumiko; Sumida, Iori; Arimura, Hidetaka; Kakinohana, Yasumasa; Kabuki, Shigeto; Monzen, Hajime; Nishio, Teiji; Shirato, Hiroki; Yamada, Syogo

    2017-01-01

    The promotion plan for the Platform of Human Resource Development for Cancer (Ganpro) was initiated by the Ministry of Education, Culture, Sports, Science and Technology of Japan in 2007, establishing a curriculum for medical physicists. In this study, we surveyed the educational outcomes of the medical physicist program over the past 10 years since the initiation of Ganpro. The Japan Society of Medical Physics mailing list was used to announce this survey. The questionnaire was created by members of the Japanese Board for Medical Physicist Qualification, and was intended for the collection of information regarding the characteristics and career paths of medical physics students. Students who participated in the medical physics program from 2007 to 2016 were enrolled. Thirty-one universities (17 accredited and 14 non-accredited) were represented in the survey. In total, 491, 105 and 6 students were enrolled in the Master's, Doctorate and Residency programs, respectively. Most students held a Bachelor's degree in radiological technology (Master's program, 87%; Doctorate program, 72%). A large number of students with a Master's degree worked as radiological technologists (67%), whereas only 9% (n = 32) worked as medical physicists. In contrast, 53% (n = 28) of the students with a Doctorate degree worked as medical physicists. In total, 602 students (from 31 universities) completed the survey. Overall, although the number of the graduates who worked as medical physicists was small, this number increased annually. It thus seems that medical institutions in Japan are recognizing the necessity of licensed medical physicists in the radiotherapy community.

  5. Clinical Training of Medical Physicists Specializing in Nuclear Medicine (Spanish Edition)

    International Nuclear Information System (INIS)

    2013-01-01

    The application of radiation in human health, for both diagnosis and treatment of disease, is an important component of the work of the IAEA. The responsibility for the increasingly technical aspects of this work is undertaken by the medical physicist. To ensure good practice in this vital area, structured clinical training programmes are required to complement academic learning. This publication is intended to be a guide to the practical implementation of such a programme for nuclear medicine. There is a general and growing awareness that radiation medicine is increasingly dependent on well trained medical physicists who are based in a clinical setting. However an analysis of the availability of medical physicists indicates a large shortfall of qualified and capable professionals. This is particularly evident in developing countries. While strategies to increase educational opportunities are critical to such countries, the need for guidance on structured clinical training was recognized by the members of the Regional Cooperative Agreement for Research, Development and Training related to Nuclear Science and Technology (RCA) for the Asia-Pacific region. Consequently, a technical cooperation regional project (RAS6038) under the RCA programme was formulated to address this need in this region by developing suitable material and establishing its viability. Development of a clinical training guide for medical physicists specialising in nuclear medicine was started in 2009 with the appointment of a core drafting committee of regional and international experts. The publication drew on the experience of clinical training in Australia, Croatia and Sweden and was moderated by physicists working in the Asian region. The present publication follows the approach of earlier IAEA publications in the Training Course Series, specifically Nos 37 and 47, Clinical Training of Medical Physicists Specializing in Radiation Oncology and Clinical Training of Medical Physicists

  6. Clinical Training of Medical Physicists Specializing in Nuclear Medicine (French Edition)

    International Nuclear Information System (INIS)

    2012-01-01

    The application of radiation in human health, for both diagnosis and treatment of disease, is an important component of the work of the IAEA. The responsibility for the increasingly technical aspects of this work is undertaken by the medical physicist. To ensure good practice in this vital area, structured clinical training programmes are required to complement academic learning. This publication is intended to be a guide to the practical implementation of such a programme for nuclear medicine. There is a general and growing awareness that radiation medicine is increasingly dependent on well trained medical physicists who are based in a clinical setting. However an analysis of the availability of medical physicists indicates a large shortfall of qualified and capable professionals. This is particularly evident in developing countries. While strategies to increase educational opportunities are critical to such countries, the need for guidance on structured clinical training was recognized by the members of the Regional Cooperative Agreement for Research, Development and Training related to Nuclear Science and Technology (RCA) for the Asia-Pacific region. Consequently, a technical cooperation regional project (RAS6038) under the RCA programme was formulated to address this need in this region by developing suitable material and establishing its viability. Development of a clinical training guide for medical physicists specialising in nuclear medicine was started in 2009 with the appointment of a core drafting committee of regional and international experts. The publication drew on the experience of clinical training in Australia, Croatia and Sweden and was moderated by physicists working in the Asian region. The present publication follows the approach of earlier IAEA publications in the Training Course Series, specifically Nos 37 and 47, Clinical Training of Medical Physicists Specializing in Radiation Oncology and Clinical Training of Medical Physicists

  7. Magnetic excitations in ferromagnetic semiconductors

    International Nuclear Information System (INIS)

    Furdyna, J.K.; Liu, X.; Zhou, Y.Y.

    2009-01-01

    Magnetic excitations in a series of GaMnAs ferromagnetic semiconductor films were studied by ferromagnetic resonance (FMR). Using the FMR approach, multi-mode spin wave resonance spectra have been observed, whose analysis provides information on magnetic anisotropy (including surface anisotropy), distribution of magnetization precession within the GaMnAs film, dynamic surface spin pinning (derived from surface anisotropy), and the value of exchange stiffness constant D. These studies illustrate a combination of magnetism and semiconductor physics that is unique to magnetic semiconductors

  8. Semiconductor Nanocrystals for Biological Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Aihua; Gu, Weiwei; Larabell, Carolyn; Alivisatos, A. Paul

    2005-06-28

    Conventional organic fluorophores suffer from poor photo stability, narrow absorption spectra and broad emission feature. Semiconductor nanocrystals, on the other hand, are highly photo-stable with broad absorption spectra and narrow size-tunable emission spectra. Recent advances in the synthesis of these materials have resulted in bright, sensitive, extremely photo-stable and biocompatible semiconductor fluorophores. Commercial availability facilitates their application in a variety of unprecedented biological experiments, including multiplexed cellular imaging, long-term in vitro and in vivo labeling, deep tissue structure mapping and single particle investigation of dynamic cellular processes. Semiconductor nanocrystals are one of the first examples of nanotechnology enabling a new class of biomedical applications.

  9. The second physicist on the history of theoretical physics in germany

    CERN Document Server

    Jungnickel, Christa

    2017-01-01

    This book explores the rise of theoretical physics in 19th century Germany. The authors show how the junior second physicist in German universities over time became the theoretical physicist, of equal standing to the experimental physicist. Gustav Kirchhoff, Hermann von Helmholtz, and Max Planck are among the great German theoretical physicists whose work and career are examined in this book. Physics was then the only natural science in which theoretical work developed into a major teaching and research specialty in its own right. Readers will discover how German physicists arrived at a well-defined field of theoretical physics with well understood and generally accepted goals and needs. The authors explain the nature of the work of theoretical physics with many examples, taking care always to locate the research within the workplace. The book is a revised and shortened version of Intellectual Mastery of Nature: Theoretical Physics from Ohm to Einstein, a two-volume work by the same authors. This new edition ...

  10. Code of Ethics for the American Association of Physicists in Medicine: report of Task Group 109.

    Science.gov (United States)

    Serago, Christopher F; Adnani, Nabil; Bank, Morris I; BenComo, Jose A; Duan, Jun; Fairobent, Lynne; Freedman, D Jay; Halvorsen, Per H; Hendee, William R; Herman, Michael G; Morse, Richard K; Mower, Herbert W; Pfeiffer, Douglas E; Root, William J; Sherouse, George W; Vossler, Matthew K; Wallace, Robert E; Walters, Barbara

    2009-01-01

    A comprehensive Code of Ethics for the members of the American Association of Physicists in Medicine (AAPM) is presented as the report of Task Group 109 which consolidates previous AAPM ethics policies into a unified document. The membership of the AAPM is increasingly diverse. Prior existing AAPM ethics polices were applicable specifically to medical physicists, and did not encompass other types of members such as health physicists, regulators, corporate affiliates, physicians, scientists, engineers, those in training, or other health care professionals. Prior AAPM ethics policies did not specifically address research, education, or business ethics. The Ethics Guidelines of this new Code of Ethics have four major sections: professional conduct, research ethics, education ethics, and business ethics. Some elements of each major section may be duplicated in other sections, so that readers interested in a particular aspect of the code do not need to read the entire document for all relevant information. The prior Complaint Procedure has also been incorporated into this Code of Ethics. This Code of Ethics (PP 24-A) replaces the following AAPM policies: Ethical Guidelines for Vacating a Position (PP 4-B); Ethical Guidelines for Reviewing the Work of Another Physicist (PP 5-C); Guidelines for Ethical Practice for Medical Physicists (PP 8-D); and Ethics Complaint Procedure (PP 21-A). The AAPM Board of Directors approved this Code or Ethics on July 31, 2008.

  11. History and development of medical physics and medical physicist in Japan

    International Nuclear Information System (INIS)

    Toyofuku, F.

    2014-01-01

    The history of medical physics in Japan dates back to the mid-1950's when radioisotope sources such as cobalt-60 were initiated into hospitals. In 1961, a total of about 30 medical physics researchers created a sub-committee of medical physics under the Japan Radiological Society (JRS), which flourished throughout the decade, and the number of members exceeded to more than 200 in 1970. Although there were great advances in medical technologies, the number of members of the medical physics community did not grow for the next two decades from 1980 to 2000. Then, the JRS began to officially recognize medical physicists as a professional group in 1987. Qualifications of candidacy for the examination included having the education equivalent of a Bachelor of Science/Engineering and being a member of the JRS. For the first official examination, 70 medical physicists were approved by the JRS. As of 2013, there are currently 700 medical physicists, however, the number of practicing clinical medical physicists remains only about 150. The main reason for this limited number of medical physicists is that the certification is not recognized as a national license and therefore is challenging to find professional employment as qualified medical personnel at hospitals. (author)

  12. State of the art in semiconductor detectors

    International Nuclear Information System (INIS)

    Rehak, P.; Gatti, E.

    1990-01-01

    The state of the art in semiconductor detectors for elementary particle physics and X-ray astronomy is briefly reviewed. Semiconductor detectors are divided into two groups; i) classical semiconductor diode detectors and ii) semiconductor memory detectors. Principles of signal formation for both groups of detectors are described and their performance is compared. New developments of silicon detectors are reported here. (orig.)

  13. State of the art in semiconductor detectors

    International Nuclear Information System (INIS)

    Rehak, P.; Gatti, E.

    1989-01-01

    The state of the art in semiconductor detectors for elementary particle physics and x-ray astronomy is briefly reviewed. Semiconductor detectors are divided into two groups; classical semiconductor diode detectors; and semiconductor memory detectors. Principles of signal formation for both groups of detectors are described and their performance is compared. New developments of silicon detectors are reported here. 13 refs., 8 figs

  14. Semiconductor device comprising a pn-heterojunction

    NARCIS (Netherlands)

    2007-01-01

    An electric device is disclosed comprising a pn-heterojunction ( 4 ) formed by a nanowire ( 3 ) of 111 -V semiconductor material and a semiconductor body ( 1 ) comprising a group IV semiconductor material. The nanowire ( 3 ) is positioned in direct contact with the surface ( 2 ) of the semiconductor

  15. Toward designing semiconductor-semiconductor heterojunctions for photocatalytic applications

    Science.gov (United States)

    Zhang, Liping; Jaroniec, Mietek

    2018-02-01

    Semiconductor photocatalysts show a great potential for environmental and energy-related applications, however one of the major disadvantages is their relatively low photocatalytic performance due to the recombination of electron-hole pairs. Therefore, intensive research is being conducted toward design of heterojunctions, which have been shown to be effective for improving the charge-transfer properties and efficiency of photocatalysts. According to the type of band alignment and direction of internal electric field, heterojunctions are categorized into five different types, each of which is associated with its own charge transfer characteristics. Since the design of heterojunctions requires the knowledge of band edge positions of component semiconductors, the commonly used techniques for the assessment of band edge positions are reviewed. Among them the electronegativity-based calculation method is applied for a large number of popular visible-light-active semiconductors, including some widely investigated bismuth-containing semiconductors. On basis of the calculated band edge positions and the type of component semiconductors reported, heterojunctions composed of the selected bismuth-containing semiconductors are proposed. Finally, the most popular synthetic techniques for the fabrication of heterojunctions are briefly discussed.

  16. Method of manufacturing a semiconductor device and semiconductor device obtained with such a method

    NARCIS (Netherlands)

    2008-01-01

    The invention relates to a method of manufacturing a semiconductor device (10) with a semiconductor body (1) which is provided with at least one semiconductor element, wherein on the surface of the semiconductor body (1) a mesa- shaped semiconductor region (2) is formed, a masking layer (3) is

  17. Selective, electrochemical etching of a semiconductor

    Science.gov (United States)

    Dahal, Rajendra P.; Bhat, Ishwara B.; Chow, Tat-Sing

    2018-03-20

    Methods for facilitating fabricating semiconductor structures are provided which include: providing a multilayer structure including a semiconductor layer, the semiconductor layer including a dopant and having an increased conductivity; selectively increasing, using electrochemical processing, porosity of the semiconductor layer, at least in part, the selectively increasing porosity utilizing the increased conductivity of the semiconductor layer; and removing, at least in part, the semiconductor layer with the selectively increased porosity from the multilayer structure. By way of example, the selectively increasing porosity may include selectively, anodically oxidizing, at least in part, the semiconductor layer of the multilayer structure.

  18. Metal-insulator-semiconductor photodetectors.

    Science.gov (United States)

    Lin, Chu-Hsuan; Liu, Chee Wee

    2010-01-01

    The major radiation of the sun can be roughly divided into three regions: ultraviolet, visible, and infrared light. Detection in these three regions is important to human beings. The metal-insulator-semiconductor photodetector, with a simpler process than the pn-junction photodetector and a lower dark current than the MSM photodetector, has been developed for light detection in these three regions. Ideal UV photodetectors with high UV-to-visible rejection ratio could be demonstrated with III-V metal-insulator-semiconductor UV photodetectors. The visible-light detection and near-infrared optical communications have been implemented with Si and Ge metal-insulator-semiconductor photodetectors. For mid- and long-wavelength infrared detection, metal-insulator-semiconductor SiGe/Si quantum dot infrared photodetectors have been developed, and the detection spectrum covers atmospheric transmission windows.

  19. Metal-Insulator-Semiconductor Photodetectors

    Directory of Open Access Journals (Sweden)

    Chu-Hsuan Lin

    2010-09-01

    Full Text Available The major radiation of the Sun can be roughly divided into three regions: ultraviolet, visible, and infrared light. Detection in these three regions is important to human beings. The metal-insulator-semiconductor photodetector, with a simpler process than the pn-junction photodetector and a lower dark current than the MSM photodetector, has been developed for light detection in these three regions. Ideal UV photodetectors with high UV-to-visible rejection ratio could be demonstrated with III-V metal-insulator-semiconductor UV photodetectors. The visible-light detection and near-infrared optical communications have been implemented with Si and Ge metal-insulator-semiconductor photodetectors. For mid- and long-wavelength infrared detection, metal-insulator-semiconductor SiGe/Si quantum dot infrared photodetectors have been developed, and the detection spectrum covers atmospheric transmission windows.

  20. Quantum optics with semiconductor nanostructures

    CERN Document Server

    Jahnke, Frank

    2012-01-01

    A guide to the theory, application and potential of semiconductor nanostructures in the exploration of quantum optics. It offers an overview of resonance fluorescence emission.$bAn understanding of the interaction between light and matter on a quantum level is of fundamental interest and has many applications in optical technologies. The quantum nature of the interaction has recently attracted great attention for applications of semiconductor nanostructures in quantum information processing. Quantum optics with semiconductor nanostructures is a key guide to the theory, experimental realisation, and future potential of semiconductor nanostructures in the exploration of quantum optics. Part one provides a comprehensive overview of single quantum dot systems, beginning with a look at resonance fluorescence emission. Quantum optics with single quantum dots in photonic crystal and micro cavities are explored in detail, before part two goes on to review nanolasers with quantum dot emitters. Light-matter interaction...

  1. Atomic layer deposition for semiconductors

    CERN Document Server

    Hwang, Cheol Seong

    2014-01-01

    This edited volume discusses atomic layer deposition (ALD) for all modern semiconductor devices, moving from the basic chemistry of ALD and modeling of ALD processes to sections on ALD for memories, logic devices, and machines.

  2. Semiconductor technology program. Progress briefs

    Science.gov (United States)

    Bullis, W. M.

    1980-01-01

    Measurement technology for semiconductor materials, process control, and devices is reviewed. Activities include: optical linewidth and thermal resistance measurements; device modeling; dopant density profiles; resonance ionization spectroscopy; and deep level measurements. Standardized oxide charge terminology is also described.

  3. Semiconductor radiation detectors. Device physics

    International Nuclear Information System (INIS)

    Lutz, G.

    2007-01-01

    Starting from basic principles, the author, whose own contributions to these developments have been significant, describes the rapidly growing field of modern semiconductor detectors used for energy and position measurement radiation. This development was stimulated by requirements in elementary particle physics where it has led to important scientific discoveries. It has now spread to many other fields of science and technology. The book is written in a didactic way and includes an introduction to semiconductor physics. The working principles of semiconductor radiation detectors are explained in an intuitive way, followed by formal quantitative analysis. Broad coverage is also given to electronic signal readout and to the subject of radiation damage. The book is the first to comprehensively cover the semiconductor radiation detectors currently in use. It is useful as a teaching guide and as a reference work for research and applications. (orig.)

  4. Self-assembling peptide semiconductors

    Science.gov (United States)

    Tao, Kai; Makam, Pandeeswar; Aizen, Ruth; Gazit, Ehud

    2017-01-01

    Semiconductors are central to the modern electronics and optics industries. Conventional semiconductive materials bear inherent limitations, especially in emerging fields such as interfacing with biological systems and bottom-up fabrication. A promising candidate for bioinspired and durable nanoscale semiconductors is the family of self-assembled nanostructures comprising short peptides. The highly ordered and directional intermolecular π-π interactions and hydrogen-bonding network allow the formation of quantum confined structures within the peptide self-assemblies, thus decreasing the band gaps of the superstructures into semiconductor regions. As a result of the diverse architectures and ease of modification of peptide self-assemblies, their semiconductivity can be readily tuned, doped, and functionalized. Therefore, this family of electroactive supramolecular materials may bridge the gap between the inorganic semiconductor world and biological systems. PMID:29146781

  5. Temperature controller of semiconductor laser

    Czech Academy of Sciences Publication Activity Database

    Matoušek, Vít; Číp, Ondřej

    2003-01-01

    Roč. 73, č. 3 (2003), s. 10 - 12 ISSN 0928-5008 Institutional research plan: CEZ:AV0Z2065902 Keywords : temperature controller * semiconductor laser * laser diode Subject RIV: BH - Optics, Masers, Lasers

  6. Wake fields in semiconductor plasmas

    International Nuclear Information System (INIS)

    Berezhiani, V.I.; Mahajan, S.M.

    1994-05-01

    It is shown that an intense short laser pulse propagating through a semiconductor plasma will generated longitudinal Langmuir waves in its wake. The measurable wake field can be used as a diagnostic to study nonlinear optical phenomena. For narrow gap semiconductors (for examples InSb) with Kane-type dispersion relation, the system can simulate, at currently available laser powers, the physics underlying wake-field accelerators. (author). 9 refs, 1 fig

  7. Semiconductor research with reactor neutrons

    International Nuclear Information System (INIS)

    Kimura, Itsuro

    1992-01-01

    Reactor neutrons play an important role for characterization of semiconductor materials as same as other advanced materials. On the other hand reactor neutrons bring about not only malignant irradiation effects called radiation damage, but also useful effects such as neutron transmutation doping and defect formation for opto-electronics. Research works on semiconductor materials with the reactor neutrons of the Kyoto University Reactor (KUR) are briefly reviewed. In this review, a stress is laid on the present author's works. (author)

  8. Semiconductor crystal high resolution imager

    Science.gov (United States)

    Levin, Craig S. (Inventor); Matteson, James (Inventor)

    2011-01-01

    A radiation imaging device (10). The radiation image device (10) comprises a subject radiation station (12) producing photon emissions (14), and at least one semiconductor crystal detector (16) arranged in an edge-on orientation with respect to the emitted photons (14) to directly receive the emitted photons (14) and produce a signal. The semiconductor crystal detector (16) comprises at least one anode and at least one cathode that produces the signal in response to the emitted photons (14).

  9. Dissipative chaos in semiconductor superlattices

    Directory of Open Access Journals (Sweden)

    F. Moghadam

    2008-03-01

    Full Text Available In this paper the motion of electron in a miniband of a semiconductor superlattice (SSL under the influence of external electric and magnetic fields is investigated. The electric field is applied in a direction perpendicular to the layers of the semiconductor superlattice, and the magnetic field is applied in different direction Numerical calculations show conditions led to the possibility of chaotic behaviors.

  10. The Mental Aftermath - The Mentality of German Physicists 1945-1949

    Science.gov (United States)

    Hentschel, Klaus

    2007-01-01

    Few scientific communities have been more thoroughly studied than 20th-century German physicists. Yet their behavior and patterns of thinking immediately after the war remains puzzling. During the first five postwar years they suspended their internecine battles and a strange solidarity emerged. Former enemies were suddenly willing to exonerate each other blindly and even morally upright physicists began to write tirades against the 'denazification mischief' or the 'export of scientists'. Personal idiosyncracies melded into a strangely uniform pattern of rejection or resistance to the Allied occupiers, with attendant repressed feelings and self-pity. Politics was once again perceived as remote, dirty business. It was feared that the least concession of guilt would bring down even more severe sanctions on their discipline. Using tools from the history of mentality, such as analysis of serial publications, these tendenciesare examined. The perspective of emigre physicists, as reflected in their private letters and reports, embellish this portrait.

  11. WE-G-19A-01: Radiologists and Medical Physicists: Working Together to Achieve Common Goals

    Energy Technology Data Exchange (ETDEWEB)

    Jones, A; Ma, J; Steele, J; Choi, H [UT MD Anderson Cancer Center, Houston, TX (United States)

    2014-06-15

    It is vitally important that medical physicists understand the clinical questions that radiologists are trying to answer with patient images. Knowledge of the types of information the radiologist needs helps medical physicists configure imaging protocols that appropriately balance radiation dose, time, and image quality. The ability to communicate with radiologists and understand medical terminology, anatomy, and physiology is key to creating such imaging protocols. In this session, radiologists will present clinical cases and describe the information they are seeking in the clinical images. Medical physicists will then discuss how imaging protocols are configured. Learning Objectives: Understand the types of information that radiologists seek in medical images. Apply this understanding in configuring the imaging equipment to deliver this information. Develop strategies for working with physician colleagues.

  12. A questionnaire survey of medical physicist and quality manager for radiation therapy

    International Nuclear Information System (INIS)

    Nishio, Teiji; Ashino, Yasuo; Onishi, Hiroshi

    2008-01-01

    A questionnaire survey of medical physicists and quality managers for radiation therapy was performed by the Japanese Society for Therapeutic Radiology and Oncology (JASTRO) Future Planning Committee. We mailed the questionnaire to 726 radiotherapy facilities with the answers returned from 353 radiotherapy facilities. The result showed 178 facilities were staffed by radiotherapy workers who were licensed medical physicists or quality managers. A staff of 289 was licensed radiotherapy workers. Most of the staff were radiotherapy technologists. Quality control for radiation therapy was rated satisfactory according to each facility's assessment. Radiation therapy of high quality requires continued education of medical physicists and quality managers, in addition to keeping up with times for quality control. (author)

  13. Paul Baillon presents the book "Differential manifolds: a basic approach for experimental physicists" | 25 March

    CERN Multimedia

    CERN Library

    2014-01-01

    Tuesday 25 March 2014 at 4 p.m. in the Library, bldg. 52-1-052 "Differential manifolds: a basic approach for experimental physicists" by Paul Baillon,  World Scientific, 2013, ISBN 978-981-4449-56-4. Differential manifold is the framework of particle physics and astrophysics nowadays. It is important for all research physicists to be accustomed to it, and even experimental physicists should be able to manipulate equations and expressions in this framework. This book gives a comprehensive description of the basics of differential manifold with a full proof of elements. A large part of the book is devoted to the basic mathematical concepts, which are all necessary for the development of the differential manifold. This book is self-consistent; it starts from first principles. The mathematical framework is the set theory with its axioms and its formal logic. No special knowledge is needed. Coffee will be served from 3.30 p.m.

  14. WE-G-19A-01: Radiologists and Medical Physicists: Working Together to Achieve Common Goals

    International Nuclear Information System (INIS)

    Jones, A; Ma, J; Steele, J; Choi, H

    2014-01-01

    It is vitally important that medical physicists understand the clinical questions that radiologists are trying to answer with patient images. Knowledge of the types of information the radiologist needs helps medical physicists configure imaging protocols that appropriately balance radiation dose, time, and image quality. The ability to communicate with radiologists and understand medical terminology, anatomy, and physiology is key to creating such imaging protocols. In this session, radiologists will present clinical cases and describe the information they are seeking in the clinical images. Medical physicists will then discuss how imaging protocols are configured. Learning Objectives: Understand the types of information that radiologists seek in medical images. Apply this understanding in configuring the imaging equipment to deliver this information. Develop strategies for working with physician colleagues

  15. SU-B-BRA-00: The Medical Physicist Value Proposition for Tomorrow and Today

    International Nuclear Information System (INIS)

    Sherouse, G.

    2016-01-01

    In the current rapidly changing Healthcare environment, many groups are competing for limited resources. How can medical physicists position themselves to be a relevant stakeholder in the discussion of how those resources are allocated Our value goes beyond what can be shown in a business plan and is heavily involved with safety and quality. Three areas will be explored: What is our value? Who needs to receive that message? How do we communicate that message? To help frame the discussion in terms of how other stakeholders may view the value of medical physicists, a physician and an administrator will present their perspective. Lastly, a multidisciplinary panel will present real life examples of strategies that can be utilized today to establish the value of medical physicists. The presentation of these examples will lead into an interactive question and answer time. V. Willcut, I work for Elekta. There was no research associated with this talk.

  16. A survey of Canadian medical physicists: software quality assurance of in-house software.

    Science.gov (United States)

    Salomons, Greg J; Kelly, Diane

    2015-01-05

    This paper reports on a survey of medical physicists who write and use in-house written software as part of their professional work. The goal of the survey was to assess the extent of in-house software usage and the desire or need for related software quality guidelines. The survey contained eight multiple-choice questions, a ranking question, and seven free text questions. The survey was sent to medical physicists associated with cancer centers across Canada. The respondents to the survey expressed interest in having guidelines to help them in their software-related work, but also demonstrated extensive skills in the area of testing, safety, and communication. These existing skills form a basis for medical physicists to establish a set of software quality guidelines.

  17. A survey of Canadian medical physicists: software quality assurance of in‐house software

    Science.gov (United States)

    Kelly, Diane

    2015-01-01

    This paper reports on a survey of medical physicists who write and use in‐house written software as part of their professional work. The goal of the survey was to assess the extent of in‐house software usage and the desire or need for related software quality guidelines. The survey contained eight multiple‐choice questions, a ranking question, and seven free text questions. The survey was sent to medical physicists associated with cancer centers across Canada. The respondents to the survey expressed interest in having guidelines to help them in their software‐related work, but also demonstrated extensive skills in the area of testing, safety, and communication. These existing skills form a basis for medical physicists to establish a set of software quality guidelines. PACS number: 87.55.Qr PMID:25679168

  18. Dr. Inside and Dr. Outside: Physicists Involved With National Security and Foreign Policy

    Science.gov (United States)

    Zimmerman, Peter D.

    2009-05-01

    Physicists have had a special interest in American national security and arms control since at least the Manhattan Project. They have served our country in uniform and in the career civil service. Some have left academic careers for brief periods to work as political appointees, consultants, or resident scholars and then returned to an academic life, but often with changed goals. Some have tried government life and left nearly immediately, while others dipped a toe in and decided to stay. I will look at real-life examples, mostly using real names, drawn from my career and circle of colleagues to try to explain why some physicists have been extremely successful, why others have not, and what happens to a physicist who moved to Washington and decides to stay. I will also discuss routes into public service for those interesting in giving it a try.

  19. SU-B-BRA-00: The Medical Physicist Value Proposition for Tomorrow and Today

    Energy Technology Data Exchange (ETDEWEB)

    Sherouse, G. [Landauer Medical Physics, Glenwood, IL (United States)

    2016-06-15

    In the current rapidly changing Healthcare environment, many groups are competing for limited resources. How can medical physicists position themselves to be a relevant stakeholder in the discussion of how those resources are allocated Our value goes beyond what can be shown in a business plan and is heavily involved with safety and quality. Three areas will be explored: What is our value? Who needs to receive that message? How do we communicate that message? To help frame the discussion in terms of how other stakeholders may view the value of medical physicists, a physician and an administrator will present their perspective. Lastly, a multidisciplinary panel will present real life examples of strategies that can be utilized today to establish the value of medical physicists. The presentation of these examples will lead into an interactive question and answer time. V. Willcut, I work for Elekta. There was no research associated with this talk.

  20. Reducing leakage current in semiconductor devices

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Bin; Matioli, Elison de Nazareth; Palacios, Tomas Apostol

    2018-03-06

    A semiconductor device includes a first region having a first semiconductor material and a second region having a second semiconductor material. The second region is formed over the first region. The semiconductor device also includes a current blocking structure formed in the first region between first and second terminals of the semiconductor device. The current blocking structure is configured to reduce current flow in the first region between the first and second terminals.

  1. Optical orientation in ferromagnet/semiconductor hybrids

    International Nuclear Information System (INIS)

    Korenev, V L

    2008-01-01

    The physics of optical pumping of semiconductor electrons in ferromagnet/semiconductor hybrids is discussed. Optically oriented semiconductor electrons detect the magnetic state of a ferromagnetic film. In turn, the ferromagnetism of the hybrid can be controlled optically with the help of a semiconductor. Spin–spin interactions near the ferromagnet/semiconductor interface play a crucial role in the optical readout and the manipulation of ferromagnetism

  2. Optical orientation in ferromagnet/semiconductor hybrids

    Science.gov (United States)

    Korenev, V. L.

    2008-11-01

    The physics of optical pumping of semiconductor electrons in ferromagnet/semiconductor hybrids is discussed. Optically oriented semiconductor electrons detect the magnetic state of a ferromagnetic film. In turn, the ferromagnetism of the hybrid can be controlled optically with the help of a semiconductor. Spin-spin interactions near the ferromagnet/semiconductor interface play a crucial role in the optical readout and the manipulation of ferromagnetism.

  3. Optical Orientation in Ferromagnet/Semiconductor Hybrids

    OpenAIRE

    Korenev, V. L.

    2008-01-01

    The physics of optical pumping of semiconductor electrons in the ferromagnet/semiconductor hybrids is discussed. Optically oriented semiconductor electrons detect the magnetic state of the ferromagnetic film. In turn, the ferromagnetism of the hybrid can be controlled optically with the help of the semiconductor. Spin-spin interactions near the interface ferromagnet/semiconductor play crucial role in the optical readout and the manipulation of ferromagnetism.

  4. Semiconductors for plasmonics and metamaterials

    DEFF Research Database (Denmark)

    Naik, G.V.; Boltasseva, Alexandra

    2010-01-01

    Plasmonics has conventionally been in the realm of metal-optics. However, conventional metals as plasmonic elements in the near-infrared (NIR) and visible spectral ranges suffer from problems such as large losses and incompatibility with semiconductor technology. Replacing metals with semiconduct......Plasmonics has conventionally been in the realm of metal-optics. However, conventional metals as plasmonic elements in the near-infrared (NIR) and visible spectral ranges suffer from problems such as large losses and incompatibility with semiconductor technology. Replacing metals...... with semiconductors can alleviate these problems if only semiconductors could exhibit negative real permittivity. Aluminum doped zinc oxide (AZO) is a low loss semiconductor that can show negative real permittivity in the NIR. A comparative assessment of AZO-based plasmonic devices such as superlens and hyperlens...... with their metal-based counterparts shows that AZO-based devices significantly outperform at a wavelength of 1.55 µm. This provides a strong stimulus in turning to semiconductor plasmonics at the telecommunication wavelengths. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)....

  5. Ripening of Semiconductor Nanoplatelets.

    Science.gov (United States)

    Ott, Florian D; Riedinger, Andreas; Ochsenbein, David R; Knüsel, Philippe N; Erwin, Steven C; Mazzotti, Marco; Norris, David J

    2017-11-08

    Ostwald ripening describes how the size distribution of colloidal particles evolves with time due to thermodynamic driving forces. Typically, small particles shrink and provide material to larger particles, which leads to size defocusing. Semiconductor nanoplatelets, thin quasi-two-dimensional (2D) particles with thicknesses of only a few atomic layers but larger lateral dimensions, offer a unique system to investigate this phenomenon. Experiments show that the distribution of nanoplatelet thicknesses does not defocus during ripening, but instead jumps sequentially from m to (m + 1) monolayers, allowing precise thickness control. We investigate how this counterintuitive process occurs in CdSe nanoplatelets. We develop a microscopic model that treats the kinetics and thermodynamics of attachment and detachment of monomers as a function of their concentration. We then simulate the growth process from nucleation through ripening. For a given thickness, we observe Ostwald ripening in the lateral direction, but none perpendicular. Thicker populations arise instead from nuclei that capture material from thinner nanoplatelets as they dissolve laterally. Optical experiments that attempt to track the thickness and lateral extent of nanoplatelets during ripening appear consistent with these conclusions. Understanding such effects can lead to better synthetic control, enabling further exploration of quasi-2D nanomaterials.

  6. A semiconductor laser device

    Energy Technology Data Exchange (ETDEWEB)

    Takaro, K.; Naoki, T.; Satosi, K.; Yasutosi, K.

    1984-03-17

    A device is proposed which makes it possible to obtain single vertical mode emission in the absence of noise. Noise suppression is achieved by a method which determines the relationship between the donor densities in the second and third layers of an n type semiconductor laser, and the total output optical emission of layers with respect to the emission from the entire laser. The device consists of a photoresist film with a window applied to a 100 GaAs n type conductivity substrate using a standard method. Chemical etching through this window in the substrate is used to generate a slot approximately 1 micrometer in size. After the photoresist film is removed, the following layers are deposited from the liquid phase onto the substrate in the sequence indicated: a telurium doped protective layer of n type AlxGa(1-x) As; 2) an undoped active p type AlyGa(1-6) As layer and a tellurium doped upper protective n type conductivity GaAs layer.

  7. Semiconductor integrated circuits

    International Nuclear Information System (INIS)

    Michel, A.E.; Schwenker, R.O.; Ziegler, J.F.

    1979-01-01

    An improved method involving ion implantation to form non-epitaxial semiconductor integrated circuits. These are made by forming a silicon substrate of one conductivity type with a recessed silicon dioxide region extending into the substrate and enclosing a portion of the silicon substrate. A beam of ions of opposite conductivity type impurity is directed at the substrate at an energy and dosage level sufficient to form a first region of opposite conductivity within the silicon dioxide region. This impurity having a concentration peak below the surface of the substrate forms a region of the one conductivity type which extends from the substrate surface into the first opposite type region to a depth between the concentration peak and the surface and forms a second region of opposite conductivity type. The method, materials and ion beam conditions are detailed. Vertical bipolar integrated circuits can be made this way when the first opposite type conductivity region will function as a collector. Also circuits with inverted bipolar devices when this first region functions as a 'buried'' emitter region. (U.K.)

  8. Impurity gettering in semiconductors

    Science.gov (United States)

    Sopori, Bhushan L.

    1995-01-01

    A process for impurity gettering in a semiconductor substrate or device such as a silicon substrate or device. The process comprises hydrogenating the substrate or device at the back side thereof with sufficient intensity and for a time period sufficient to produce a damaged back side. Thereafter, the substrate or device is illuminated with electromagnetic radiation at an intensity and for a time period sufficient to cause the impurities to diffuse to the back side and alloy with a metal there present to form a contact and capture the impurities. The impurity gettering process also can function to simultaneously passivate defects within the substrate or device, with the defects likewise diffusing to the back side for simultaneous passivation. Simultaneously, substantially all hydrogen-induced damage on the back side of the substrate or device is likewise annihilated. Also taught is an alternate process comprising thermal treatment after hydrogenation of the substrate or device at a temperature of from about 500.degree. C. to about 700.degree. C. for a time period sufficient to cause the impurities to diffuse to the damaged back side thereof for subsequent capture by an alloying metal.

  9. Semiconductor acceleration sensor

    Science.gov (United States)

    Ueyanagi, Katsumichi; Kobayashi, Mitsuo; Goto, Tomoaki

    1996-09-01

    This paper reports a practical semiconductor acceleration sensor especially suited for automotive air bag systems. The acceleration sensor includes four beams arranged in a swastika structure. Two piezoresistors are formed on each beam. These eight piezoresistors constitute a Wheatstone bridge. The swastika structure of the sensing elements, an upper glass plate and a lower glass plate exhibit the squeeze film effect which enhances air dumping, by which the constituent silicon is prevented from breakdown. The present acceleration sensor has the following features. The acceleration force component perpendicular to the sensing direction can be cancelled. The cross-axis sensitivity is less than 3 percent. And, the erroneous offset caused by the differences between the thermal expansion coefficients of the constituent materials can be canceled. The high aspect ratio configuration realized by plasma etching facilitates reducing the dimensions and improving the sensitivity of the acceleration sensor. The present acceleration sensor is 3.9 mm by 3.9 mm in area and 1.2 mm in thickness. The present acceleration sensor can measure from -50 to +50 G with sensitivity of 0.275 mV/G and with non-linearity of less than 1 percent. The acceleration sensor withstands shock of 3000 G.

  10. Clinical Training of Medical Physicists Specializing in Diagnostic Radiology (French Edition)

    International Nuclear Information System (INIS)

    2012-01-01

    The application of radiation in human health, for both diagnosis and treatment of disease, is an important component of the work of the IAEA. The responsibility for the increasing technical aspects of this work is undertaken by the medical physicist. To ensure good practice in this vital area, structured clinical training programmes are required to complement academic learning. This publication is intended to be a guide to the practical implementation of such a programme for diagnostic radiology. There is a general and growing awareness that radiation medicine is increasingly dependent on well trained medical physicists based in the clinical setting. However, an analysis of the availability of medical physicists indicates a large shortfall of qualified and capable professionals. This is particularly evident in developing countries. While strategies to increase academic educational opportunities are critical to such countries, the need for guidance on structured clinical training was recognized by the members of the Regional Cooperative Agreement (RCA) for Research, Development and Training related to Nuclear Sciences for Asia and the Pacific. Consequently, a technical cooperation regional project (RAS6038) under the RCA programme was formulated to address this need in the Asia-Pacific region by developing suitable material and establishing its viability. Development of a clinical training guide for medical physicists specializing in diagnostic radiology started in 2007 with the appointment of a core drafting committee of regional and international experts. The publication drew on the experiences of clinical training programmes in Australia and New Zealand, the UK and the USA, and was moderated by physicists working in the Asian region. This publication follows the approach of the IAEA publication Training Course Series No. 37, Clinical Training of Medical Physicists specializing in Radiation Oncology. This approach to clinical training has been successfully tested

  11. Clinical Training of Medical Physicists Specializing in Diagnostic Radiology (Spanish Edition)

    International Nuclear Information System (INIS)

    2013-01-01

    The application of radiation in human health, for both diagnosis and treatment of disease, is an important component of the work of the IAEA. The responsibility for the increasing technical aspects of this work is undertaken by the medical physicist. To ensure good practice in this vital area, structured clinical training programmes are required to complement academic learning. This publication is intended to be a guide to the practical implementation of such a programme for diagnostic radiology. There is a general and growing awareness that radiation medicine is increasingly dependent on well trained medical physicists based in the clinical setting. However, an analysis of the availability of medical physicists indicates a large shortfall of qualified and capable professionals. This is particularly evident in developing countries. While strategies to increase academic educational opportunities are critical to such countries, the need for guidance on structured clinical training was recognized by the members of the Regional Cooperative Agreement (RCA) for Research, Development and Training related to Nuclear Sciences for Asia and the Pacific. Consequently, a technical cooperation regional project (RAS6038) under the RCA programme was formulated to address this need in the Asia-Pacific region by developing suitable material and establishing its viability. Development of a clinical training guide for medical physicists specializing in diagnostic radiology started in 2007 with the appointment of a core drafting committee of regional and international experts. The publication drew on the experiences of clinical training programmes in Australia and New Zealand, the UK and the USA, and was moderated by physicists working in the Asian region. This publication follows the approach of the IAEA publication Training Course Series No. 37, Clinical Training of Medical Physicists specializing in Radiation Oncology. This approach to clinical training has been successfully tested

  12. A century of nuclear science. Important contributions of early generation Chinese physicist to nuclear science

    International Nuclear Information System (INIS)

    Zheng Chunkai; Xu Furong

    2003-01-01

    The great discoveries and applications of nuclear science have had tremendous impact on the progress and development of mankind over the last 100 years. In the 1920's to 1940's, many young Chinese who yearned to save the country through science and education went to west Europe and north America to study science, including physics. Studying and working with famous physicists throughout the world, they made many important contributions and discoveries in the development of nuclear science. This paper describes the historical contributions of the older generation of Chinese physicists to nuclear science

  13. Quantum field theory I: Basics in mathematics and physics. A bridge between mathematicians and physicists

    International Nuclear Information System (INIS)

    Zeidler, Eberhard

    2009-01-01

    This is the first volume of a modern introduction to quantum field theory which addresses both mathematicians and physicists, at levels ranging from advanced undergraduate students to professional scientists. The book bridges the acknowledged gap between the different languages used by mathematicians and physicists. For students of mathematics the author shows that detailed knowledge of the physical background helps to motivate the mathematical subjects and to discover interesting interrelationships between quite different mathematical topics. For students of physics, fairly advanced mathematics is presented, which goes beyond the usual curriculum in physics. (orig.)

  14. Quantum field theory II: quantum electrodynamics. A bridge between mathematicians and physicists

    International Nuclear Information System (INIS)

    Zeidler, Eberhard

    2009-01-01

    This is the second volume of a modern introduction to quantum field theory which addresses both mathematicians and physicists ranging from advanced undergraduate students to professional scientists. This book seeks to bridge the existing gap between the different languages used by mathematicians and physicists. For students of mathematics it is shown that detailed knowledge of the physical background helps to discover interesting interrelationships between quite diverse mathematical topics. For students of physics fairly advanced mathematics, beyond that included in the usual curriculum in physics, is presented. The present volume concerns a detailed study of the mathematical and physical aspects of the quantum theory of light. (orig.)

  15. Quantum field theory I: Basics in mathematics and physics. A bridge between mathematicians and physicists

    Energy Technology Data Exchange (ETDEWEB)

    Zeidler, Eberhard [Max-Planck-Institut fuer Mathematik in den Naturwissenschaften, Leipzig (Germany)

    2009-07-01

    This is the first volume of a modern introduction to quantum field theory which addresses both mathematicians and physicists, at levels ranging from advanced undergraduate students to professional scientists. The book bridges the acknowledged gap between the different languages used by mathematicians and physicists. For students of mathematics the author shows that detailed knowledge of the physical background helps to motivate the mathematical subjects and to discover interesting interrelationships between quite different mathematical topics. For students of physics, fairly advanced mathematics is presented, which goes beyond the usual curriculum in physics. (orig.)

  16. Quantum field theory II: quantum electrodynamics. A bridge between mathematicians and physicists

    Energy Technology Data Exchange (ETDEWEB)

    Zeidler, Eberhard [Max Planck Institute for Mathematics in the Sciences, Leipzig (Germany)

    2009-07-01

    This is the second volume of a modern introduction to quantum field theory which addresses both mathematicians and physicists ranging from advanced undergraduate students to professional scientists. This book seeks to bridge the existing gap between the different languages used by mathematicians and physicists. For students of mathematics it is shown that detailed knowledge of the physical background helps to discover interesting interrelationships between quite diverse mathematical topics. For students of physics fairly advanced mathematics, beyond that included in the usual curriculum in physics, is presented. The present volume concerns a detailed study of the mathematical and physical aspects of the quantum theory of light. (orig.)

  17. Contributions to naive quantum mechanics. A textbook for mathematicians and physicists

    International Nuclear Information System (INIS)

    Kohlmann, Martin

    2009-01-01

    The present text examplifies by means of 60 citations from current textbooks for the study of physics the necessarity of a mathematically rigorous formulation of quantum mechanics. Well known statements of many physicists about quantum mechanics at their mathematical tool kit are commented in form of a dialogue und mathematical points of view. Supplemented are the representations by a selection of theorems of higher analysis relevant for quantum theory. The book applies to mathematicians and mathematically interested physicists or students with founded mathematical knowledge.

  18. Curriculum for education and training of Medical Physicists in Nuclear Medicine

    DEFF Research Database (Denmark)

    Del Guerra, Alberto; Bardies, Manuel; Belcari, Nicola

    2013-01-01

    and Competence approach along the lines recommended by the European Qualifications Framework. The minimum level expected in each topic in the theoretical knowledge and practical experience sections is intended to bring trainees up to the requirements expected of a Medical Physicist entering the field of Nuclear...... Medicine. CONCLUSIONS: This new joint EANM/EFOMP European guideline curriculum is a further step to harmonise specialist training of Medical Physicists in Nuclear Medicine within Europe. It provides a common framework for national Medical Physics societies to develop or benchmark their own curricula....... The responsibility for the implementation and accreditation of these standards and guidelines resides within national training and regulatory bodies....

  19. From falling bodies to radio waves classical physicists and their discoveries

    CERN Document Server

    Segrè, Emilio

    1984-01-01

    Meet a diverse group of highly original thinkers and learn about their lives and achievements: Galileo, a founding father of astronomy and physics; Christiaan Huygens, a seventeenth-century pioneer of wave-particle duality; and Isaac Newton, the English mathematician and physicist who laid the groundwork for a scientific revolution and promoted radical investigation as the means to reveal nature's hidden workings.This chronicle of physics and physicists traces the development of scientific thought from these originators to their successors, among them Faraday, Watts, Helmholtz, Maxwell, Boltzm

  20. Semiconductor lasers stability, instability and chaos

    CERN Document Server

    Ohtsubo, Junji

    2017-01-01

    This book describes the fascinating recent advances made concerning the chaos, stability and instability of semiconductor lasers, and discusses their applications and future prospects in detail. It emphasizes the dynamics in semiconductor lasers by optical and electronic feedback, optical injection, and injection current modulation. Applications of semiconductor laser chaos, control and noise, and semiconductor lasers are also demonstrated. Semiconductor lasers with new structures, such as vertical-cavity surface-emitting lasers and broad-area semiconductor lasers, are intriguing and promising devices. Current topics include fast physical number generation using chaotic semiconductor lasers for secure communication, development of chaos, quantum-dot semiconductor lasers and quantum-cascade semiconductor lasers, and vertical-cavity surface-emitting lasers. This fourth edition has been significantly expanded to reflect the latest developments. The fundamental theory of laser chaos and the chaotic dynamics in se...

  1. Role and responsibilities of medical physicists in radiology and membership of Bulgaria in European union

    International Nuclear Information System (INIS)

    Todorov, V.; Vassileva, J.

    2006-01-01

    Full text: Medical radiology and especially the radiotherapy is the birthplace of modern medical physics. Medical physicists have proven place and important role in research and practice in radiotherapy. They share the responsibility with physicians in varied daily work in this medical speciality. The rapid development of medical imaging in last decades increases the need of competence of medical physicists. Quality assurance in Diagnostic Radiology aimed to achieve maximum diagnostic information at minimal risk and with minimal prize, which is obligatory for the members of the EU, is impossible to be implemented without medical physicists. The enforced recently Ordinance 30/2005 of the Ministry of Health forms the regulatory basis of obligatory implementation of Quality Assurance at medical use of ionizing radiation in the country. This Ordinance introduces the requirements of the EURATOM 97/43 Directive on health protection of individuals against the dangers of ionizing radiation in relation to medical exposure. It regulates also the responsibilities of medical physicists in radiology. Forthcoming is the practical implementation of these requirements, which needs the competence and efforts of Medical physics community as well as of radiologists in the country

  2. South African Association of Physicists in Medicine and Biology: 26. annual congress

    International Nuclear Information System (INIS)

    1986-01-01

    The twenty-sixth annual congress of the South African Association of Physicists in Medicine and Biology was held from 18-21 March 1986 in Pretoria. Papers delivered on the conference covered subjects like medical physics, radiotherapy, radiation protection, calibration of radiation monitors, radiation detectors, radiation doses and dosimetry

  3. Half Life: The Divided Life of Bruno Pontecorvo, Physicist or Spy

    International Nuclear Information System (INIS)

    Close, Frank

    2016-01-01

    It was at the height of the Cold War, in the summer of 1950, when Bruno Pontecorvo mysteriously vanished behind the Iron Curtain. Who was he, and what caused him to disappear? Was he simply a physicist, or also a spy and communist radical? A protege of Enrico Fermi, Pontecorvo was one of the most promising nuclear physicists in the world. He spent years hunting for the Higgs boson of his day - the neutrino - a nearly massless particle thought to be essential to the process of particle decay. His work on the Manhattan Project helped to usher in the nuclear age, and confirmed his reputation as a brilliant physicist. Why, then, would he disappear as he stood on the cusp of true greatness, perhaps even the Nobel Prize? In this book, physicist and historian Frank Close offers a heretofore untold history of Pontecorvo's life, based on unprecedented access to Pontecorvo's friends and family and the Russian scientists with whom he would later work. Close takes a microscope to Pontecorvo's life, combining a thorough biography of one of the most important scientists of the twentieth century with the drama of Cold War espionage. With all the elements of a Cold War thriller - classified atomic research, an infamous double agent, a possible kidnapping by Soviet operatives - this book is a history of nuclear physics at perhaps its most powerful: when it created the bomb

  4. INDEFINITE CONTRACT REVIEW 1999 Procedure for Research Physicists (Professional Category 1)

    CERN Multimedia

    1999-01-01

    In view of the long-standing deliberate turnover policy of professional category 1 research physicists on fixed-term contracts, a special procedure is defined, distinct from the other professional categories. This procedure takes into account that research physicists stay at CERN for only up to 6 years and that periods of service as Fellow may be counted within these six years.The following procedure has been agreed:1.\tThe review covers research physicists holding fixed-term contracts and having completed at least 4 years of service on 30 June 1999. Prior years as Fellow may be taken into consideration in the specific context.\tAll candidates are informed individually.2.\tThe files of all candidates are considered by search committees. The members of the committees are nominated by the Director-General and comprise members of the senior CERN staff as well as at least one senior external physicist. The committees are free to take up references and to interview the candidates.3.\tIn ord...

  5. Internal qualification and credentialing of radiation oncology physicists to perform patient special procedures

    Directory of Open Access Journals (Sweden)

    Michael D Mills

    2014-01-01

    Full Text Available In the arena of radiation oncology special procedures, medical physicists are often the focus professionals for implementation and administration of advanced and complex technologies. One of the most vexing and challenging aspects of managing complexity concerns the ongoing internal qualification and credentialing of radiation oncology physicists to perform patient special procedures. To demonstrate ongoing qualification, a physicist must a document initial training and successful completion of competencies to implement and perform this procedure, b demonstrate familiarity with all aspects of the commissioning and quality assurance process, c demonstrate continuing education respecting this procedure, d demonstrate the peer-reviewed completion of a minimum number of patient special procedures during a specified time span, and e demonstrate satisfactory overall progress toward maintenance of specialty board certification. In many respects, this information complement is similar to that required by an accredited residency program in therapy physics. In this investigation, we report on the design of a management tool to qualify staff radiation oncology physicists to deliver patient procedures.

  6. Brookhaven Lab physicist William Willis wins the 2003 W.K.H. Panofsky prize

    CERN Multimedia

    2003-01-01

    William Willis, a senior physicist Brookhaven National Laboratory, has won the American Physical Society's 2003 W.K.H. Panofsky Prize in Experimental Particle Physics. He received the prize, which consists of $5,000 and a certificate citing his contributions to physics, at the APS meeting in Philadelphia on April 6 (1 page).

  7. 14. Meeting of the North and Northeast physicists. Program and abstracts

    International Nuclear Information System (INIS)

    1996-01-01

    These proceedings contain abstracts of oral and panel presentations carried out during the 14 Meeting of physicists of North and Northeast held in Aracaju, State of Sergipe, Brazil. While covering different areas of physics, they emphasized the condensed matter, statistical physics and nuclear physics in their theoretical and experimental aspects

  8. Semiconductor optoelectronic infrared spectroscopy

    International Nuclear Information System (INIS)

    Hollingworth, A.R.

    2001-08-01

    We use spectroscopy to study infrared optoelectronic inter and intraband semiconductor carrier dynamics. The overall aim of this thesis was to study both III-V and Pb chalcogenide material systems in order to show their future potential use in infrared emitters. The effects of bandstructure engineering have been studied in the output characteristics of mid-IR III-V laser diodes to show which processes (defects, radiative, Auger and phonon) dominate and whether non-radiative processes can be suppressed. A new three-beam pump probe experiment was used to investigate interband recombination directly in passive materials. Experiments on PbSe and theory for non-parabolic near-mirror bands and non-degenerate statistics were in good agreement. Comparisons with HgCdTe showed a reduction in the Auger coefficient of 1-2 orders of magnitude in the PbSe. Using Landau confinement to model spatial confinement in quantum dots (QDs) 'phonon bottlenecking' was studied. The results obtained from pump probe and cyclotron resonance saturation measurements showed a clear suppression in the cooling of carriers when Landau level separation was not resonant with LO phonon energy. When a bulk laser diode was placed in a magnetic field to produce a quasi quantum wire device the resulting enhanced differential gain and reduced Auger recombination lowered I th by 30%. This result showed many peaks in the light output which occurred when the LO phonon energy was a multiple of the Landau level separation. This showed for the first time evidence of the phonon bottleneck in a working laser device. A new technique called time resolved optically detected cyclotron resonance, was used as a precursor to finding the carrier dynamics within a spatially confined quantum dot. By moving to the case of a spatial QD using an optically detected intraband resonance it was possible to measure the energy separation interband levels and conduction and valence sublevels within the dot simultaneously. Furthermore

  9. Simulation of semiconductor devices

    International Nuclear Information System (INIS)

    Oriato, D.

    2001-09-01

    In this thesis a drift diffusion model coupled with self-consistent solutions of Poisson's and Schroedinger's equations, is developed and used to investigate the operation of Gunn diodes and GaN-based LEDs. The model also includes parameters derived from Monte Carlo calculations of the simulated devices. In this way the characteristics of a Monte Carlo approach and of a quantum solver are built into a fast and flexible drift-diffusion model that can be used for testing a large number of heterostructure designs in a time-effective way. The full model and its numerical implementation are described in chapter 2. In chapter 3 the theory of Gunn diodes is presented. A basic model of the dynamics of domain formation and domain transport is described with particular regard to accumulation and dipole domains. Several modes of operation of the Gunn device are described, varying from the resonance mode to the quenched mode. Details about transferred electron devices and negative differential resistance in semiconductor materials are given. In chapter 4 results from the simulation of a simple conventional gunn device confirm the importance of the doping condition at the cathode. Accumulation or dipole domains are achieved respectively with high and low doping densities. The limits of a conventional Gunn diode are explained and solved by introducing the heterostructure Gunn diode. This new design consists of a conventional GaAs transit region coupled with an electron launcher at the cathode, made using an AIGaAs heterostructure step. Simulations show the importance of the insertion of a thin highly-doped layer between the transit region and the electron launcher in order to improve device operation. Chapter 5 is an introduction to Ill-nitrides, in particular GaN and its alloy ln-GaN. We outline the discrepancy in the elastic and piezoelectric parameters found in the literature. Strain, dislocations and piezoelectricity are presented as the main features of a InGaN/GaN system

  10. Clinical Training of Medical Physicists Specializing in Radiation Oncology (French Ed.)

    International Nuclear Information System (INIS)

    2012-01-01

    The application of radiation in human health, for both diagnosis and treatment of disease, is an important component of the work of the IAEA. The responsibility for the increasing technical aspects of this work is undertaken by the medical physicist. To ensure good practice in this vital area structured clinical training programmes are required to complement academic learning. This publication is intended to be a guide to the practical implementation of such a programme for radiation therapy. There is a general and growing awareness that radiation medicine is increasingly dependant on well trained medical physicists that are based in the clinical setting. However an analysis of the availability of medical physicists indicates a large shortfall of qualified and capable professionals. This is particularly evident in developing countries. While strategies to increase academic educational opportunities are critical to such countries, the need for guidance on structured clinical training was recognised by the members of the Regional Cooperative Agreement (RCA) for research, development and training related to nuclear sciences for Asia and the Pacific. Consequently a technical cooperation regional project (RAS6038) under the RCA programme was formulated to address this need in the Asia Pacific region by developing suitable material and establishing its viability. Development of a clinical training guide for medical physicists specialising in radiation therapy was started in 2005 with the appointment of a core drafting committee of regional and international experts. Since 2005 the IAEA has convened two additional consultant group meetings including additional experts to prepare the present publication. The publication drew heavily, particularly in the initial stages, from the experience and documents of the Clinical Training Programme for Radiation Oncology Medical Physicists as developed by the Australasian College of Physical Scientists and Engineers in Medicine. Their

  11. Dad's in the Garage: Santa Barbara Physicists in the Long 1970s

    Science.gov (United States)

    Mody, Cyrus

    2013-03-01

    American physicists faced many challenges in the 1970s: declining research budgets; public skepticism of scientific authority; declining student enrollments; and pressure to shift to topics such as biomedicine, environmental remediation, alternative energy, public housing and transport, and disability technologies. This paper examines the responses to these challenges of a small group of Santa Barbara physicists. While this group is not representative of the American physics profession, the success and failure of their responses to changed conditions tells us something about how American physicists got through the 1970s, and about the origins of some features of American physics today. The three physicists examined here are Philip Wyatt, David Phillips, and Virgil Elings. In the late `60s, Wyatt left a defense think tank to found an instrumentation firm. The Santa Barbara oil spill and other factors pushed that firm toward civilian markets in biomedicine and pollution measurement. Phillips joined Wyatt's firm from UCSB, while also founding his own company, largely to sell electronic devices for parapsychology. Phillips was also the junior partner in a master's of scientific instrumentation degree curriculum founded by Elings in order to save UCSB Physics' graduate program. Through the MSI program, Elings moved into biomedical research and became a serial entrepreneur. By the 1990s, Wyatt, Phillips, and Elings' turn toward academic entrepreneurship, dual military-civilian markets for physics start-ups, and interdisciplinary collaborations between physicists and life scientists were no longer unusual. Together, their journey through the `70s shows how varied the physics' profession's response to crisis was, and how much it pivoted on new interactions between university and industry.

  12. Clinical Training of Medical Physicists Specializing in Radiation Oncology (Spanish Ed.)

    International Nuclear Information System (INIS)

    2012-01-01

    The application of radiation in human health, for both diagnosis and treatment of disease, is an important component of the work of the IAEA. The responsibility for the increasing technical aspects of this work is undertaken by the medical physicist. To ensure good practice in this vital area structured clinical training programmes are required to complement academic learning. This publication is intended to be a guide to the practical implementation of such a programme for radiation therapy. There is a general and growing awareness that radiation medicine is increasingly dependant on well trained medical physicists that are based in the clinical setting. However an analysis of the availability of medical physicists indicates a large shortfall of qualified and capable professionals. This is particularly evident in developing countries. While strategies to increase academic educational opportunities are critical to such countries, the need for guidance on structured clinical training was recognised by the members of the Regional Cooperative Agreement (RCA) for research, development and training related to nuclear sciences for Asia and the Pacific. Consequently a technical cooperation regional project (RAS6038) under the RCA programme was formulated to address this need in the Asia Pacific region by developing suitable material and establishing its viability. Development of a clinical training guide for medical physicists specialising in radiation therapy was started in 2005 with the appointment of a core drafting committee of regional and international experts. Since 2005 the IAEA has convened two additional consultant group meetings including additional experts to prepare the present publication. The publication drew heavily, particularly in the initial stages, from the experience and documents of the Clinical Training Programme for Radiation Oncology Medical Physicists as developed by the Australasian College of Physical Scientists and Engineers in Medicine. Their

  13. High pressure semiconductor physics I

    CERN Document Server

    Willardson, R K; Paul, William; Suski, Tadeusz

    1998-01-01

    Since its inception in 1966, the series of numbered volumes known as Semiconductors and Semimetals has distinguished itself through the careful selection of well-known authors, editors, and contributors. The "Willardson and Beer" Series, as it is widely known, has succeeded in publishing numerous landmark volumes and chapters. Not only did many of these volumes make an impact at the time of their publication, but they continue to be well-cited years after their original release. Recently, Professor Eicke R. Weber of the University of California at Berkeley joined as a co-editor of the series. Professor Weber, a well-known expert in the field of semiconductor materials, will further contribute to continuing the series' tradition of publishing timely, highly relevant, and long-impacting volumes. Some of the recent volumes, such as Hydrogen in Semiconductors, Imperfections in III/V Materials, Epitaxial Microstructures, High-Speed Heterostructure Devices, Oxygen in Silicon, and others promise indeed that this tra...

  14. Introduction to cathodoluminescence in semiconductors

    International Nuclear Information System (INIS)

    Dussac, M.

    1985-01-01

    The use of cathodoluminescence in a scanning electron microscope leads to acquire a spectrum in a place of the sample surface, or to register the intensity profile of a special emission band along a scanning line, or also to realize a map of the irradiated sample. Composition variations can then, at ambient temperature, be determined, also defects can be shown, together with grain joints and dislocations, radiative and non radiative regions can be distinguished and, at low temperature, elementary processes of luminescence can be studied and impurities identified in semiconductors. Through this analysis method is applicable to every insulating or semiconductor material (that is to say to every material having a gap), in this article only crystalline semi-conductor will be studied [fr

  15. Catalysts, Protection Layers, and Semiconductors

    DEFF Research Database (Denmark)

    Chorkendorff, Ib

    2015-01-01

    Hydrogen is the simplest solar fuel to produce and in this presentation we shall give a short overview of the pros and cons of various tandem devices [1]. The large band gap semiconductor needs to be in front, but apart from that we can chose to have either the anode in front or back using either...... acid or alkaline conditions. Since most relevant semiconductors are very prone to corrosion the advantage of using buried junctions and using protection layers offering shall be discussed [2-4]. Next we shall discuss the availability of various catalysts for being coupled to these protections layers...... and how their stability may be evaluated [5, 6]. Examples of half-cell reaction using protection layers for both cathode and anode will be discussed though some of recent examples under both alkaline and acidic conditions. Si is a very good low band gap semiconductor and by using TiO2 as a protection...

  16. High mobility emissive organic semiconductor

    Science.gov (United States)

    Liu, Jie; Zhang, Hantang; Dong, Huanli; Meng, Lingqiang; Jiang, Longfeng; Jiang, Lang; Wang, Ying; Yu, Junsheng; Sun, Yanming; Hu, Wenping; Heeger, Alan J.

    2015-01-01

    The integration of high charge carrier mobility and high luminescence in an organic semiconductor is challenging. However, there is need of such materials for organic light-emitting transistors and organic electrically pumped lasers. Here we show a novel organic semiconductor, 2,6-diphenylanthracene (DPA), which exhibits not only high emission with single crystal absolute florescence quantum yield of 41.2% but also high charge carrier mobility with single crystal mobility of 34 cm2 V−1 s−1. Organic light-emitting diodes (OLEDs) based on DPA give pure blue emission with brightness up to 6,627 cd m−2 and turn-on voltage of 2.8 V. 2,6-Diphenylanthracene OLED arrays are successfully driven by DPA field-effect transistor arrays, demonstrating that DPA is a high mobility emissive organic semiconductor with potential in organic optoelectronics. PMID:26620323

  17. Thiophene-Based Organic Semiconductors.

    Science.gov (United States)

    Turkoglu, Gulsen; Cinar, M Emin; Ozturk, Turan

    2017-10-24

    Thiophene-based π-conjugated organic small molecules and polymers are the research subject of significant current interest owing to their potential use as organic semiconductors in material chemistry. Despite simple and similar molecular structures, the hitherto reported properties of thiophene-based organic semiconductors are rather diverse. Design of high performance organic semiconducting materials requires a thorough understanding of inter- and intra-molecular interactions, solid-state packing, and the influence of both factors on the charge carrier transport. In this chapter, thiophene-based organic semiconductors, which are classified in terms of their chemical structures and their structure-property relationships, are addressed for the potential applications as organic photovoltaics (OPVs), organic field-effect transistors (OFETs) and organic light emitting diodes (OLEDs).

  18. Organic semiconductors in sensor applications

    CERN Document Server

    Malliaras, George; Owens, Róisín

    2008-01-01

    Organic semiconductors offer unique characteristics such as tunability of electronic properties via chemical synthesis, compatibility with mechanically flexible substrates, low-cost manufacturing, and facile integration with chemical and biological functionalities. These characteristics have prompted the application of organic semiconductors and their devices in physical, chemical, and biological sensors. This book covers this rapidly emerging field by discussing both optical and electrical sensor concepts. Novel transducers based on organic light-emitting diodes and organic thin-film transistors, as well as systems-on-a-chip architectures are presented. Functionalization techniques to enhance specificity are outlined, and models for the sensor response are described.

  19. Semiconductors and semimetals epitaxial microstructures

    CERN Document Server

    Willardson, Robert K; Beer, Albert C; Gossard, Arthur C

    1994-01-01

    Newly developed semiconductor microstructures can now guide light and electrons resulting in important consequences for state-of-the-art electronic and photonic devices. This volume introduces a new generation of epitaxial microstructures. Special emphasis has been given to atomic control during growth and the interrelationship between the atomic arrangements and the properties of the structures.Key Features* Atomic-level control of semiconductor microstructures* Molecular beam epitaxy, metal-organic chemical vapor deposition* Quantum wells and quantum wires* Lasers, photon(IR)detectors, heterostructure transistors

  20. Introduction to semiconductor manufacturing technology

    CERN Document Server

    2012-01-01

    IC chip manufacturing processes, such as photolithography, etch, CVD, PVD, CMP, ion implantation, RTP, inspection, and metrology, are complex methods that draw upon many disciplines. [i]Introduction to Semiconductor Manufacturing Technologies, Second Edition[/i] thoroughly describes the complicated processes with minimal mathematics, chemistry, and physics; it covers advanced concepts while keeping the contents accessible to readers without advanced degrees. Designed as a textbook for college students, this book provides a realistic picture of the semiconductor industry and an in-depth discuss

  1. Wide gap semiconductor microwave devices

    International Nuclear Information System (INIS)

    Buniatyan, V V; Aroutiounian, V M

    2007-01-01

    A review of properties of wide gap semiconductor materials such as diamond, diamond-like carbon films, SiC, GaP, GaN and AlGaN/GaN that are relevant to electronic, optoelectronic and microwave applications is presented. We discuss the latest situation and perspectives based on experimental and theoretical results obtained for wide gap semiconductor devices. Parameters are taken from the literature and from some of our theoretical works. The correspondence between theoretical results and parameters of devices is critically analysed. (review article)

  2. Detection of radioactivity by semiconductors

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    The class of detectors discussed in this chapter has a responsive component involving a diode, a junction between two types of semiconductor materials. Although diode detectors are not particularly efficient in counting radioactive emissions, they are superior to other commercially available detectors in spectroscopy. Consequently, diode detectors are used extensively for quanlitative purposes and for quantitative purposes when mixtures of radionuclides are present, not the usual situation with biological or medical research. Topics addressed in this chapter are as follows: Band Theory; Semiconductors and Junctions; and Radiation Detectors. 6 refs., 14 figs

  3. Modeling of semiconductor optical amplifiers

    DEFF Research Database (Denmark)

    Mørk, Jesper; Bischoff, Svend; Berg, Tommy Winther

    We discuss the modelling of semiconductor optical amplifiers with emphasis on their high-speed properties. Applications in linear amplification as well as ultrafast optical signal processing are reviewed. Finally, the possible role of quantum-dot based optical amplifiers is discussed.......We discuss the modelling of semiconductor optical amplifiers with emphasis on their high-speed properties. Applications in linear amplification as well as ultrafast optical signal processing are reviewed. Finally, the possible role of quantum-dot based optical amplifiers is discussed....

  4. Semiconductor X-ray spectrometers

    International Nuclear Information System (INIS)

    Muggleton, A.H.F.

    1978-02-01

    An outline is given of recent developments in particle and photon induced x-ray fluorescence (XRF) analysis. Following a brief description of the basic mechanism of semiconductor detector operation a comparison is made between semiconductor detectors, scintillators and gas filled proportional devices. Detector fabrication and cryostat design are described in more detail and the effects of various device parameters on system performance, such as energy resolution, count rate capability, efficiency, microphony, etc. are discussed. The main applications of these detectors in x-ray fluorescence analysis, electron microprobe analysis, medical and pollution studies are reviewed

  5. Integrating magnetism into semiconductor electronics

    Energy Technology Data Exchange (ETDEWEB)

    Zakharchenya, Boris P; Korenev, Vladimir L [A.F. Ioffe Physico-Technical Institute, Russian Academy of Sciences, St. Petersburg (Russian Federation)

    2005-06-30

    The view of a ferromagnetic-semiconducting hybrid structure as a single tunable system is presented. Based on an analysis of existing experiments it is shown that, contrary to a 'common sense', a nonmagnetic semiconductor is capable of playing an important role in controlling ferromagnetism. Magnetic properties of a hybrid (the hysteresis loop and the spatial orientation of magnetization) can be tuned both optically and electrically by utilizing semiconductor-making the hybrid an electronic-write-in and electronic-read-out elementary storage unit. (methodological notes)

  6. Integrating magnetism into semiconductor electronics

    International Nuclear Information System (INIS)

    Zakharchenya, Boris P; Korenev, Vladimir L

    2005-01-01

    The view of a ferromagnetic-semiconducting hybrid structure as a single tunable system is presented. Based on an analysis of existing experiments it is shown that, contrary to a 'common sense', a nonmagnetic semiconductor is capable of playing an important role in controlling ferromagnetism. Magnetic properties of a hybrid (the hysteresis loop and the spatial orientation of magnetization) can be tuned both optically and electrically by utilizing semiconductor-making the hybrid an electronic-write-in and electronic-read-out elementary storage unit. (methodological notes)

  7. Semiconductor lasers and herterojunction leds

    CERN Document Server

    Kressel, Henry

    2012-01-01

    Semiconductor Lasers and Heterojunction LEDs presents an introduction to the subject of semiconductor lasers and heterojunction LEDs. The book reviews relevant basic solid-state and electromagnetic principles; the relevant concepts in solid state physics; and the p-n junctions and heterojunctions. The text also describes stimulated emission and gain; the relevant concepts in electromagnetic field theory; and the modes in laser structures. The relation between electrical and optical properties of laser diodes; epitaxial technology; binary III-V compounds; and diode fabrication are also consider

  8. Waveguide based external cavity semiconductor lasers

    NARCIS (Netherlands)

    Oldenbeuving, Ruud; Klein, E.J.; Offerhaus, Herman L.; Lee, Christopher James; Verhaegen, M.; Boller, Klaus J.

    2012-01-01

    We report on progress of the project waveguide based external cavity semiconductor laser (WECSL) arrays. Here we present the latest results on our efforts to mode lock an array of tunable, external cavity semiconductor lasers.

  9. Influence of phonons on semiconductor quantum emission

    Energy Technology Data Exchange (ETDEWEB)

    Feldtmann, Thomas

    2009-07-06

    A microscopic theory of interacting charge carriers, lattice vibrations, and light modes in semiconductor systems is presented. The theory is applied to study quantum dots and phonon-assisted luminescence in bulk semiconductors and heterostructures. (orig.)

  10. Semiconductor structure and recess formation etch technique

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Bin; Sun, Min; Palacios, Tomas Apostol

    2017-02-14

    A semiconductor structure has a first layer that includes a first semiconductor material and a second layer that includes a second semiconductor material. The first semiconductor material is selectively etchable over the second semiconductor material using a first etching process. The first layer is disposed over the second layer. A recess is disposed at least in the first layer. Also described is a method of forming a semiconductor structure that includes a recess. The method includes etching a region in a first layer using a first etching process. The first layer includes a first semiconductor material. The first etching process stops at a second layer beneath the first layer. The second layer includes a second semiconductor material.

  11. Fundamentals of semiconductors physics and materials properties

    CERN Document Server

    Yu, Peter Y

    2005-01-01

    Provides detailed explanations of the electronic, vibrational, transport, and optical properties of semiconductors. This textbook emphasizes understanding the physical properties of Si and similar tetrahedrally coordinated semiconductors and features an extensive collection of tables of material parameters, figures, and problems.

  12. Nuclear radiation detection by a variband semiconductor

    International Nuclear Information System (INIS)

    Volkov, A.S.

    1981-01-01

    Possibilities of using a variband semiconductor for detecting nuclear radiations are considered. It is shown that the variaband quasielectric field effectively collects charges induced by a nuclear particle only at a small mean free path in the semiconductor (up to 100 μm), the luminescence spectrum of the variband semiconductor when a nuclear particle gets into it, in principle, permits to determine both the energy and mean free path in the semiconductor (even at large mean free paths) [ru

  13. Ultrafast THz Saturable Absorption in Doped Semiconductors

    DEFF Research Database (Denmark)

    Turchinovich, Dmitry; Hoffmann, Matthias C.

    2011-01-01

    We demonstrate ultrafast THz saturable absorption in n-doped semiconductors by nonlinear THz time-domain spectroscopy. This effect is caused by the semiconductor conductivity modulation due to electron heating and satellite-valley scattering in strong THz fields.......We demonstrate ultrafast THz saturable absorption in n-doped semiconductors by nonlinear THz time-domain spectroscopy. This effect is caused by the semiconductor conductivity modulation due to electron heating and satellite-valley scattering in strong THz fields....

  14. Laser semiconductor diode integrated with frequency doubler

    International Nuclear Information System (INIS)

    Tighineanu, I.; Dorogan, V.; Suruceanu, G.

    2003-01-01

    The invention relates to the technology of optoelectronic semiconductor devices and may be used in the production of laser semiconductor diodes integrated with optical nonlinear elements. The laser semiconductor diode integrated with frequency doubler includes a semiconductor substrate, a laser structure with waveguide. metal contacts in the waveguide of the laser structure it is formed a nanostructured field so that the nanostructure provides for the fulfillment of the phase synchronism conditions

  15. Diode having trenches in a semiconductor region

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, Tomas Apostol; Lu, Bin; Matioli, Elison de Nazareth

    2016-03-22

    An electrode structure is described in which conductive regions are recessed into a semiconductor region. Trenches may be formed in a semiconductor region, such that conductive regions can be formed in the trenches. The electrode structure may be used in semiconductor devices such as field effect transistors or diodes. Nitride-based power semiconductor devices are described including such an electrode structure, which can reduce leakage current and otherwise improve performance.

  16. Automation and Integration in Semiconductor Manufacturing

    OpenAIRE

    Liao, Da-Yin

    2010-01-01

    Semiconductor automation originates from the prevention and avoidance of frauds in daily fab operations. As semiconductor technology and business continuously advance and grow, manufacturing systems must aggressively evolve to meet the changing technical and business requirements in this industry. Semiconductor manufacturing has been suffering pains from islands of automation. The problems associated with these systems are limited

  17. Semiconductor nanostructures for infrared applications

    NARCIS (Netherlands)

    Zurauskiene, N.; Asmontas, S.; Dargys, A.; Kundrotas, J.; Janssen, G.; Goovaerts, E.; Marcinkevicius, S.; Koenraad, P.M.; Wolter, J.H.; Leon, R.

    2004-01-01

    We present the results of time-resolved photoluminescence (TRPL) and optically detected microwave resonance (ODMR) spectroscopy investigations of semiconductor quantum dots and quantum wells. The ODMR spectra of InAs/GaAs QDs were detected via modulation of the total intensity of the QDs emission

  18. A Brief History of ... Semiconductors

    Science.gov (United States)

    Jenkins, Tudor

    2005-01-01

    The development of studies in semiconductor materials is traced from its beginnings with Michael Faraday in 1833 to the production of the first silicon transistor in 1954, which heralded the age of silicon electronics and microelectronics. Prior to the advent of band theory, work was patchy and driven by needs of technology. However, the arrival…

  19. Semiconductor radiation detectors: device physics

    National Research Council Canada - National Science Library

    Lutz, Gerhard

    1999-01-01

    ..., including nuclear physics, elementary particle physics, optical and x-ray astronomy, medicine, and materials testing - and the number of applications is growing continually. Closely related, and initiated by the application of semiconductors, is the development of low-noise low-power integrated electronics for signal readout. The success of semicond...

  20. Towards filament free semiconductor lasers

    DEFF Research Database (Denmark)

    McInerney, John; O'Brien, Peter; Skovgaard, Peter M. W.

    2000-01-01

    We outline physical models and simulations for suppression of self-focusing and filamentation in large aperture semiconductor lasers. The principal technical objective is to generate multi-watt CW or quasi-CW outputs with nearly diffraction limited beams, suitable for long distance free space...... propagation structures in lasers and amplifiers which suppress lateral reflections....

  1. Ultrafast Spectroscopy of Semiconductor Devices

    DEFF Research Database (Denmark)

    Borri, Paola; Langbein, Wolfgang; Hvam, Jørn Marcher

    1999-01-01

    In this work we present an experimental technique for investigating ultrafast carrier dynamics in semiconductor optical amplifiers at room temperature. These dynamics, influenced by carrier heating, spectral hole-burning and two-photon absorption, are very important for device applications in inf...

  2. Radiation damage in semiconductor detectors

    International Nuclear Information System (INIS)

    Kraner, H.W.

    1981-12-01

    A survey is presented of the important damage-producing interactions in semiconductor detectors and estimates of defect numbers are made for MeV protons, neutrons and electrons. Damage effects of fast neutrons in germanium gamma ray spectrometers are given in some detail. General effects in silicon detectors are discussed and damage constants and their relationship to leakage current is introduced

  3. Transient photoconductivity in amorphous semiconductors

    International Nuclear Information System (INIS)

    Mpawenayo, P.

    1997-07-01

    Localized states in amorphous semiconductors are divided in disorder induced shallow trap levels and dangling bonds deep states. Dangling bonds are assumed here to be either neutral or charged and their energy distribution is a single gaussian. Here, it is shown analytically that transient photocurrent in amorphous semiconductors is fully controlled by charge carriers transitions between localized states for one part and tunneling hopping carriers on the other. Localized dangling bonds deep states act as non radiative recombination centres, while hopping tunnelling is assisted by the Coulomb interaction between defects sites. The half-width of defects distribution is the disorder parameter that determines the carrier hopping time between defects sites. The macroscopic time that explains the long decay response times observed will all types of amorphous semiconductors is duly thought to be temperature dependent. Basic equations developed by Longeaud and Kleider are solved for the general case of a semiconductor after photo-generation. It turns out that the transient photoconductivity decay has two components; one with short response times from carriers trap-release transitions between shallow levels and extended states and a hopping component made of inter-dependent exponentials whose time constants span in larger ranges depending on disorder. The photoconductivity hopping component appears as an additional term to be added to photocurrents derived from existing models. The results of the present study explain and complete the power law decay derived in the multiple trapping models developed 20 years ago only in the approximation of the short response time regime. The long response time regime is described by the hopping macroscopic time. The present model is verified for all samples of amorphous semiconductors known so far. Finally, it is proposed to improved the modulated photoconductivity calculation techniques by including the long-lasting hopping dark documents

  4. A half-life the divided life of Bruno Pontecorvo, physicist or spy

    CERN Document Server

    Close, Frank

    2015-01-01

    Bruno Pontecorvo dedicated his career to hunting for the Higgs boson of his day: the neutrino, a nearly massless particle considered essential to the process of nuclear fission. His work on the Manhattan project under Enrico Fermi confirmed his reputation as a brilliant physicist and helped usher in the nuclear age. He should have won a Nobel Prize, but late in the summer of 1950 he vanished. At the height of the Cold War, Pontecorvo had disappeared behind the Iron Curtain. In Half-Life, physicist and historian Frank Close offers a heretofore untold history of Pontecorvo’s life, based on unprecedented access to his friends, family, and colleagues. With all the elements of a Cold War thriller—classified atomic research, an infamous double agent, a kidnapping by Soviet operatives—Half-Life is a history of particle physics at perhaps its most powerful: when it created the bomb.

  5. Fermi: a physicist in the upheaval; Fermi: un physicien dans la tourmente

    Energy Technology Data Exchange (ETDEWEB)

    Maria, M. de

    2002-07-01

    This book summarizes the life, works and complex personality of the Italian physicist Enrico Fermi (1901-1954) whose myth is linked with the political upheaval of the 2. world war: the youth of an autodidact, the theorician and the quantum mechanics, his invention of a quantum statistics, the weak interaction theory, his works on artificial radioactivity, the end of the Fermi team and his exile in the USA, the secrete researches at the university of Columbia and the birth of the first atomic 'pile' (December 2, 1942), the building of Los Alamos center and the Alamogordo explosion test, the disagreements among the physicists of the Manhattan project and the position of Fermi, Fermi's contribution in the H-bomb construction, the creation of the physics school of Chicago, the Oppenheimer spying affair. (J.S.)

  6. Role of the medical physicist in quality control in diagnostic x-ray departments

    International Nuclear Information System (INIS)

    Cameron, J.R.

    1973-01-01

    Medical physicists can play a role in education of future radiologists and technologists by teaching quality control needs and techniques. He or she can also provide service to the diagnostic section by establishing a quality control program. Finally, the medical physicist can play an important role in the development of simple and inexpensive techniques for quality control by radiological technologists. The ongoing work at the University of Wisconsin in this area is to provide quality control in measurement of the effective kVcp, the measurement of the effective focal spot size, the performance of the processing equipment, the output in mR/mAs, and the measurement of the half-value-layer and the total filtration. (U.S.)

  7. Compendium to radiation physics for medical physicists 300 problems and solutions

    CERN Document Server

    Podgorsak, Ervin B

    2014-01-01

    This exercise book contains 300 typical problems and exercises in modern physics and radiation physics with complete solutions, detailed equations and graphs. This textbook is linked directly with the textbook "Radiation Physics for Medical Physicists", Springer (2010) but can also be used in combination with other related textbooks. For ease of use, this textbook has exactly the same organizational layout (14 chapters, 128 sections) as the "Radiation Physics for Medical Physicists" textbook and each section is covered by at least one problem with solution given. Equations, figures and tables are cross-referenced between the two books. It is the only large compilation of textbook material and associated solved problems in medical physics, radiation physics, and biophysics.

  8. General programs of specialized education of radiological physicists in the Czech Republic

    International Nuclear Information System (INIS)

    Dvorak, P.; Judas, L.; Richter, V.; Novak, L.

    2005-01-01

    Specialized Education of Czech radiological physicists in diagnostic radiology (DR), nuclear medicine (NM) or radiotherapy (RT) follows-up to regulated university master program. A form and content of Specialized Education which will be defined by General Programs must therefore reflect previous step. Graduates from Specialized Education will be fully competent clinical radiological physicists for DR, NM or RT according to their branch. Therefore, we strongly recommend that General Programs are made very carefully reflecting requirements of Specialized Education and current status of the field in the Czech Republic. Currently, CAMP works on its own version of General Program for each branch. CAMP is ready to collaborate closely with all other bodies included in preparation of General Programs and with the Czech Ministry of Health. (authors)

  9. Women physicists in Russia: Problems and solutions at a time of fiscal crisis

    Science.gov (United States)

    Didenko, Nelli; Ermolaeva, Elena; Kunitsyna, Ekaterina; Kratasyuk, Valentina; Vitman, Renata

    2013-03-01

    Recently Russia has been affected by the global financial crisis, which has had both positive and negative effects on women physicists. The feminization of science and the stratification that characterize the Russian scientific community in general also affect the field of physics. This paper discusses the proportion of women in leadership and managerial positions in different areas of science and education and highlights the differences between women and men in their careers in physics and defense of their theses. Lomonosov Moscow State University is used to demonstrate the dynamics of gender in different academic positions. The professional activity of young women physicists is illustrated by their participation in all-Russian scientific forums, demonstrating their commitment to remain active in their careers despite the challenges of the current economic conditions.

  10. The radioactivity, the sun, the Earth and Kelvin's death. A difficult dialog between physicists and geologists

    International Nuclear Information System (INIS)

    Richet, P.

    1996-01-01

    The question of the age of the Earth has remained mythical for a long time. During the last quarter of the 19. century, this question was the center of a strong controversy initiated by a physicist, William Thomson, the future Lord Kelvin. During the beginning of the 20. century, the discoveries of Becquerel and Pierre and Marie Curie about radioactivity gave rise to a new generation of physicists who were able to propose radiometric estimations of the Earth's age to geologists. This digest paper describes the historical aspects of the discovery of radioactivity and of the first attempts for dating the Earth using radiometric techniques, and the strong discussions within the geologists community. (J.S.)

  11. The role of medical physicist in health care and radiation protection

    International Nuclear Information System (INIS)

    Mattsson, S.; Adliene, D.

    2004-01-01

    Medical physics is a part of physics that is associated with the practice of medicine dealing with a use of various types of ionizing and non-ionizing radiation for medical purposes as well as with the radiation protection of patients and personnel. The role, responsibilities and duties of medical physicists in the fields of radiation therapy, diagnostic imaging using X-rays and magnetic resonance methods, diagnostics and therapeutic nuclear medicine, radiation dosimetry and radiation protection are discussed in this paper. It is shown that, the medical physicists have the unique possibility to combine their knowledge in medical radiation physics with the recent achievements in medicine and technology and to apply this knowledge for the adequately safe treatment or diagnosis of patients during radiological procedures. (author)

  12. The role of the biomedical physicist in the education of the healthcare professions: an EFOMP project.

    Science.gov (United States)

    Caruana, C J; Wasilewska-Radwanska, M; Aurengo, A; Dendy, P P; Karenauskaite, V; Malisan, M R; Meijer, J H; Mornstein, V; Rokita, E; Vano, E; Wucherer, M

    2009-09-01

    The role of the biomedical physicist in the education of the healthcare professions has not yet been studied in a systematic manner. This article presents the first results of an EFOMP project aimed at researching and developing this important component of the role of the biomedical physicist. A background to the study expands on the reasons that led to the need for the project. This is followed by an extensive review of the published literature regarding the role. This focuses mainly on the teaching contributions within programmes for physicians, diagnostic radiographers, radiation therapists, and the postgraduate medical specializations of radiology, radiotherapy, interventional radiology and cardiology. Finally a summary list of the specific research objectives that need to be immediately addressed is presented. These are the carrying out of a Europe-wide position audit for the role, the construction of a strategic role development model and the design of a curriculum development model suitable for modern healthcare professional education.

  13. MO-C-BRB-04: Observations of a Nuclear Radiologist on the Value of the Medical Physicist

    International Nuclear Information System (INIS)

    Greenspan, B.

    2016-01-01

    With the profound changes currently occurring in medicine, the role of the medical physicist cannot stagnate, but must evolve to meet the challenges and opportunities that are presented. Medical physicists must understand these changes and establish themselves not only as relevant but as leaders in this new environment. We must increase our presence in clinical settings such as tumor boards, patient rounds, and the development of new diagnosis, imaging, and treatment techniques. By establishing ourselves as competent scientists, we can and must participate in the development of technologies through research, teaching, and clinical implementation. As medical physicists we must define our roles and value to our physician colleagues, patients, referring physicians, and senior administrators. We cannot afford to be viewed solely as quality assurance technologists, but need to move forward in step with medical and practice advances, becoming recognized as having a leadership role in providing quality research, technological development, and quality patient care. In this session, four leaders in medical research and healthcare will discuss their observations on how medical physicists have contributed to advancements in healthcare and opportunities to continue leadership in providing quality medicine through the applications of physics to research, education, and clinical practice. Learning Objectives: Understand the changes in the healthcare environment and how medical physicists can contribute to improving patient care. Learn how medical physicists are currently leading research efforts to improve clinical imaging and diagnosis. Understand the role of medical physicists in developing new technology and leading its translation into clinical care.

  14. MO-C-BRB-04: Observations of a Nuclear Radiologist on the Value of the Medical Physicist

    Energy Technology Data Exchange (ETDEWEB)

    Greenspan, B. [Georgia Regents University (Georgia)

    2016-06-15

    With the profound changes currently occurring in medicine, the role of the medical physicist cannot stagnate, but must evolve to meet the challenges and opportunities that are presented. Medical physicists must understand these changes and establish themselves not only as relevant but as leaders in this new environment. We must increase our presence in clinical settings such as tumor boards, patient rounds, and the development of new diagnosis, imaging, and treatment techniques. By establishing ourselves as competent scientists, we can and must participate in the development of technologies through research, teaching, and clinical implementation. As medical physicists we must define our roles and value to our physician colleagues, patients, referring physicians, and senior administrators. We cannot afford to be viewed solely as quality assurance technologists, but need to move forward in step with medical and practice advances, becoming recognized as having a leadership role in providing quality research, technological development, and quality patient care. In this session, four leaders in medical research and healthcare will discuss their observations on how medical physicists have contributed to advancements in healthcare and opportunities to continue leadership in providing quality medicine through the applications of physics to research, education, and clinical practice. Learning Objectives: Understand the changes in the healthcare environment and how medical physicists can contribute to improving patient care. Learn how medical physicists are currently leading research efforts to improve clinical imaging and diagnosis. Understand the role of medical physicists in developing new technology and leading its translation into clinical care.

  15. Communication and information-seeking behavior of PhD students in physicists and astronomy

    OpenAIRE

    Jamali, Hamid R.

    2006-01-01

    As a part of a wider doctoral research, this paper deals with the communication and information-seeking behavior of research (PhD) students in physics and astronomy. Based on a qualitative case study of PhD students in the Department of Physics and Astronomy at University College London, this study seeks to derive behavioral patterns in information-seeking activities of PhD students. The study aims to investigate the intradisciplinary differences in information-seeking activities of physicist...

  16. Salary Information for Nuclear Engineers and Health Physicists, October 1995; FINAL

    International Nuclear Information System (INIS)

    Oak Ridge Institute for Science and Education

    1995-01-01

    Salary information was collected for October 1995 for personnel working as nuclear engineers and health physicists. The salary information includes personnel at the B.S., M.S., and Ph.D. levels with zero, one, and three years of professional work experience. Information is provided for utilities and non-utilities. Non-utilities include private sector organizations and U.S. Department of Energy contractor-operated facilities. Government agencies, the military, academic organizations, and medical facilities are excluded

  17. Procedure for physicist's scanning in the image processing system of bubble chambers

    International Nuclear Information System (INIS)

    Gritsaenko, I.A.; Petrovykh, L.P.; Petrovykh, Yu.L.; Fenyuk, A.B.

    1984-01-01

    The algorithm of the program of physicist's scanning for data processing from photo images in experiments using bubble chambers is described. The program allows one to perform sorting or selection of specific events for subsequent processing and identification of separate particles by bubble density along the track or by the character of the decay. The fraction of protons separated automatically constituted 97%. The program has been used for processing 50 thousand events at the BEBC chamber

  18. Limited Resources, Limited Opportunities, and the Accumulation of Disadvantage: Evidence from the Global Survey of Physicists

    Science.gov (United States)

    Ivie, Rachel

    2012-03-01

    Using the results of the Global Survey of Physicists, which we conducted in collaboration with the International Union of Pure and Applied Physics Working Group on Women, we document the effect of limited resources and opportunities on women physicists' careers. We find that women respondents are less likely than men to report access to a variety of resources and opportunities that would be helpful in advancing a scientific career. These include access to funding, travel money, lab and office space, equipment, clerical support, and availability of employees or students to help with research. When asked about specific opportunities, women report fewer invited talks and overseas research opportunities. Women who responded are less likely to have been journal editors, acted as bosses or managers, advised graduate students, served on thesis or dissertation committees, and served on committees for grant agencies. We also show the disproportionate effects of children on women physicists' careers. Women who responded are more likely than men to have changed their work situations upon becoming parents. Mothers are more likely than men and women without children to report that their careers have progressed more slowly than colleagues who finished their degrees at the same time. Furthermore, women are more likely than men to report that their careers affected the decisions they made about marriage and children. The results of this survey draw attention to the need to focus on factors other than representation when discussing the situation of women in physics. 15,000 physicists in 130 countries answered this survey, and across all these countries, women have fewer resources and opportunities and are more affected by cultural expectations concerning child care. Cultural expectations about home and family are difficult to change. However, for women to have successful outcomes and advance in physics, they must have equal access to resources and opportunities.

  19. Qualification diploma in radiological and medical physics. Evolution of the initial training of hospital physicists

    International Nuclear Information System (INIS)

    Hammadi, A.

    2009-01-01

    This series of slides presents: - the evolution of the radio-physicists training since its creation (history, 1995-2005 era, 2005-2009 changes); - the qualification diploma in radiological and medical physics (QDRMP - DQPRM in French) in figures (validating services, number of qualified people); - the QDRMP context and goals (strength needs, limited number of candidates); - the means implemented to reach the goals; - the perspectives (increase of students number, continuous training). (J.S.)

  20. Role and responsibilities of medical physicists in radiological protection of patients

    International Nuclear Information System (INIS)

    Niroomand-Rad, A.

    2001-01-01

    The paper provides a brief history of the International Organization for Medical Physics (IOMP), followed by some general comments on the radiological protection of patients. The importance of establishing scientific guidelines and professional standards is emphasized, as is the need to ensure the protection of patients undergoing radiation therapy. The responsibility of qualified medical physicists in the protection of patients in nuclear medicine and in diagnostic and interventional radiology is also discussed. (author)

  1. Entrepreneurship for Physicists; A practical guide to move inventions from university to market

    Science.gov (United States)

    Iannuzzi, Davide

    2017-10-01

    This book offers a concise analysis of the key ingredients that enable physicists to successfully move their idea from university to market, bringing added value to their customers. It dives into a set of theories, models, and tools that play fundamental roles in technology transfer including topics often neglected by other books including trust, communication, and persuasion. It also explains how most of the topics discussed are applicable to careers in a broader sense.

  2. Anniversary Paper: The role of medical physicists in developing stereotactic radiosurgery

    International Nuclear Information System (INIS)

    Benedict, Stanley H.; Bova, Frank J.; Clark, Brenda; Goetsch, Steven J.; Hinson, William H.; Leavitt, Dennis D.; Schlesinger, David J.; Yenice, Kamil M.

    2008-01-01

    This article is a tribute to the pioneering medical physicists over the last 50 years who have participated in the research, development, and commercialization of stereotactic radiosurgery (SRS) and stereotactic radiotherapy utilizing a wide range of technology. The authors have described the evolution of SRS through the eyes of physicists from its beginnings with the Gamma Knife in 1951 to proton and charged particle therapy; modification of commercial linacs to accommodate high precision SRS setups; the multitude of accessories that have enabled fine tuning patients for relocalization, immobilization, and repositioning with submillimeter accuracy; and finally the emerging technology of SBRT. A major theme of the article is the expanding role of the medical physicist from that of advisor to the neurosurgeon to the current role as a primary driver of new technology that has already led to an adaptation of cranial SRS to other sites in the body, including, spine, liver, and lung. SRS continues to be at the forefront of the impetus to provide technological precision for radiation therapy and has demonstrated a host of downstream benefits in improving delivery strategies for conventional therapy as well. While this is not intended to be a comprehensive history, and the authors could not delineate every contribution by all of those working in the pursuit of SRS development, including physicians, engineers, radiobiologists, and the rest of the therapy and dosimetry staff in this important and dynamic radiation therapy modality, it is clear that physicists have had a substantial role in the development of SRS and theyincreasingly play a leading role in furthering SRS technology

  3. UC Riverside physicists contribute to state-of-the-art detector installed in Switzerland

    CERN Multimedia

    2008-01-01

    PMUC Riverside scientists led by Gail Hanson, a distinguished professor of physics, are part of a collaboration of approximately 2300 international physicists who announced Dec. 19 that the world 's largest silicon tracking detector at CERN in Geneva, Switzerland, had been successfully installed (see also ). Called the CMS (Compact Muon Solenoid) Silicon Strip Tracking Detector, the six-ton instrument has a total surface area of 205 square meters, about the same as a singles tennis court.

  4. UC Riverside physicists contribute to state-of-the-art detector installed in Switzerland

    CERN Multimedia

    2008-01-01

    UC Riverside scientists led by Gail Hanson, a distinguished professor of physics, are part of a collaboration of approximately 2300 international physicists who announced Dec. 19 that the world's largest silicon tracking detector at CERN in Geneva, Switzerland, had been successfully installed (see also ). Called the CMS (Compact Muon Solenoid) Silicon Strip Tracking Detector, the six-ton instrument has a total surface area of 205 square meters, about the same as a singles tennis court.

  5. Scientific productivity and academic promotion: a study on French and Italian physicists

    OpenAIRE

    Francesco Lissoni; Jacques Mairesse; Fabio Montobbio; Michele Pezzoni

    2011-01-01

    The article examines the determinants of scientific productivity (number of articles and journals' impact factor) for a panel of about 3600 French and Italian academic physicists active in 2004--2005. Endogeneity problems concerning promotion and productivity are addressed by specifying a generalized Tobit model, in which a selection probit equation accounts for the individual scientist's probability of promotion to her present rank, and a productivity regression estimates the effects of age,...

  6. Physicists to mark 20th anniversary of first string theory revolution

    CERN Document Server

    2004-01-01

    "Growing numbers of physicists see superstring theory as their best chance to formulate a set of natural laws that govern everything from the largest galaxies to the smallest quarks in one grand unifying theory of everything. The two men who started the revolution, Michael Green, now of the University of Cambridge, and John Schwarz of the California Institute of Technology, also will speak at the symposium" (1.5 pages)

  7. Physicists' views on hadrontherapy: a survey of members of the Italian Association of Medical Physics (AIFM).

    Science.gov (United States)

    Giandini, Tommaso; Tenconi, Chiara; Carrara, Mauro; Ciocca, Mario; Russo, Stefania; Panaino, Costanza M V; Cattani, Federica; Ciardo, Delia; Morlino, Sara; Avuzzi, Barbara; Bedini, Nice; Villa, Sergio; Marvaso, Giulia; Romanelli, Paola; Hasegawa, Azusa; Vischioni, Barbara; Valvo, Francesca; Jereczek-Fossa, Barbara A; Orecchia, Roberto; Valdagni, Riccardo; Pignoli, Emanuele

    2017-09-18

    This study was based on a survey to investigate perceptions of hadrontherapy of the members of the Italian Association of Medical Physics (AIFM). The survey was digitally submitted to the 991 members between the end of January and the beginning of April 2016. A 19-item questionnaire was designed focusing on advantages and disadvantages of hadrontherapy, current status and possible future improvements, and need and opportunities for future investments in Italy and abroad. Information about professional qualifications, main fields of clinical involvement and specific competencies of the respondents was also collected. The survey was completed by 121 AIFM members (response rate 12.2%). In the answers collected, it was shown that medical physicists expressed interest in hadrontherapy mainly for reasons of personal interest rather than for professional needs (90% ± 2.5% vs. 52% ± 4.3% of the respondents, respectively), with a good knowledge of the related basic aspects as well as of the pros and cons of its application. However, poor knowledge of the current status of hadrontherapy was observed among the medical physicists not directly involved at a professional level, who were less than 3% of the physicists working in radiotherapy. In light of these results, the implementation of new training and education initiatives should be devised to promote a deeper and global knowledge of hadrontherapy-related issues, not only from a theoretical point of view but also in practical terms. Moreover, a close collaboration between highly specialized medical physicists employed in hadrontherapy centers and others in oncology hospitals should be -encouraged.

  8. Fermi level dependent native defect formation: Consequences for metal-semiconductor and semiconductor-semiconductor interfaces

    International Nuclear Information System (INIS)

    Walukiewicz, W.

    1988-02-01

    The amphoteric native defect model of the Schottky barrier formation is used to analyze the Fermi level pinning at metal/semiconductor interfaces for submonolayer metal coverages. It is assumed that the energy required for defect generation is released in the process of surface back-relaxation. Model calculations for metal/GaAs interfaces show a weak dependence of the Fermi level pinning on the thickness of metal deposited at room temperature. This weak dependence indicates a strong dependence of the defect formation energy on the Fermi level, a unique feature of amphoteric native defects. This result is in very good agreement with experimental data. It is shown that a very distinct asymmetry in the Fermi level pinning on p- and n-type GaAs observed at liquid nitrogen temperatures can be understood in terms of much different recombination rates for amphoteric native defects in those two types of materials. Also, it is demonstrated that the Fermi level stabilization energy, a central concept of the amphoteric defect system, plays a fundamental role in other phenomena in semiconductors such as semiconductor/semiconductor heterointerface intermixing and saturation of free carrier concentration. 33 refs., 6 figs

  9. Semiconductor detectors in nuclear and particle physics

    International Nuclear Information System (INIS)

    Rehak, P.; Gatti, E.

    1992-01-01

    Semiconductor detectors for elementary particle physics and nuclear physics in the energy range above 1 GeV are briefly reviewed. In these two fields semiconductor detectors are used mainly for the precise position sensing. In a typical experiment, the position of a fast charged particle crossing a relatively thin semiconductor detector is measured. The position resolution achievable by semiconductor detectors is compared with the resolution achievable by gas filled position sensing detectors. Semiconductor detectors are divided into two groups: Classical semiconductor diode detectors and semiconductor memory detectors. Principles of the signal formation and the signal read-out for both groups of detectors are described. New developments of silicon detectors of both groups are reported

  10. Semiconductor detectors in nuclear and particle physics

    International Nuclear Information System (INIS)

    Rehak, P.; Gatti, E.

    1995-01-01

    Semiconductor detectors for elementary particle physics and nuclear physics in the energy range above 1 GeV are briefly reviewed. In these two fields semiconductor detectors are used mainly for the precise position sensing. In a typical experiment, the position of a fast charged particle crossing a relatively thin semiconductor detector is measured. The position resolution achievable by semiconductor detectors is compared with the resolution achievable by gas filled position sensing detectors. Semiconductor detectors are divided into two groups; (i) classical semiconductor diode detectors and (ii) semiconductor memory detectors. Principles of the signal formation and the signal read-out for both groups of detectors are described. New developments of silicon detectors of both groups are reported. copyright 1995 American Institute of Physics

  11. Transversal light forces in semiconductors

    CERN Document Server

    Lindberg, M

    2003-01-01

    The transversal light force is a well established effect in atomic and molecular systems that are exposed to spatially inhomogeneous light fields. In this paper it is shown theoretically that in an excited semiconductor, containing an electron-hole plasma or excitons, a similar light force exists, if the semiconductor is exposed to an ultrashort spatially inhomogeneous light field. The analysis is based on the equations of motion for the Wigner distribution functions of charge carrier populations and interband polarizations. The results show that, while the light force on the electron-hole plasma or the excitons does exist, its effects on the kinetic behaviour of the electron-hole plasma or the excitons are different compared to the situation in an atomic or molecular system. A detailed analysis presented here traces this difference back to the principal differences between atoms and molecules on the one hand and electron-hole plasmas or excitons on the other hand.

  12. Semiconductor electrolyte photovoltaic energy converter

    Science.gov (United States)

    Anderson, W. W.; Anderson, L. B.

    1975-01-01

    Feasibility and practicality of a solar cell consisting of a semiconductor surface in contact with an electrolyte are evaluated. Basic components and processes are detailed for photovoltaic energy conversion at the surface of an n-type semiconductor in contact with an electrolyte which is oxidizing to conduction band electrons. Characteristics of single crystal CdS, GaAs, CdSe, CdTe and thin film CdS in contact with aqueous and methanol based electrolytes are studied and open circuit voltages are measured from Mott-Schottky plots and open circuit photo voltages. Quantum efficiencies for short circuit photo currents of a CdS crystal and a 20 micrometer film are shown together with electrical and photovoltaic properties. Highest photon irradiances are observed with the GaAs cell.

  13. Hypersonic modes in nanophononic semiconductors.

    Science.gov (United States)

    Hepplestone, S P; Srivastava, G P

    2008-09-05

    Frequency gaps and negative group velocities of hypersonic phonon modes in periodically arranged composite semiconductors are presented. Trends and criteria for phononic gaps are discussed using a variety of atomic-level theoretical approaches. From our calculations, the possibility of achieving semiconductor-based one-dimensional phononic structures is established. We present results of the location and size of gaps, as well as negative group velocities of phonon modes in such structures. In addition to reproducing the results of recent measurements of the locations of the band gaps in the nanosized Si/Si{0.4}Ge{0.6} superlattice, we show that such a system is a true one-dimensional hypersonic phononic crystal.

  14. Dielectric function of semiconductor superlattice

    International Nuclear Information System (INIS)

    Qin Guoyi.

    1990-08-01

    We present a calculation of the dielectric function for semiconductor GaAs/Ga 1-x Al x As superlattice taking account of the extension of the electron envelope function and the difference of both the dielectric constant and width between GaAs and Ga 1-x Al x As layers. In the appropriate limits, our results exactly reduce to the well-known results of the quasi two-dimensional electron gas obtained by Lee and Spector and of the period array of two-dimensional electron layers obtained by Das Sarma and Quinn. By means of the dielectric function of the superlattice, the dispersion relation of the collective excitation and the screening property of semiconductor superlattice are discussed and compared with the results of the quasi two-dimensional system and with the results of the periodic array of the two-dimensional electron layers. (author). 4 refs, 3 figs

  15. Efficient Spin Injection into Semiconductor

    International Nuclear Information System (INIS)

    Nahid, M.A.I.

    2010-06-01

    Spintronic research has made tremendous progress nowadays for making future devices obtain extra advantages of low power, and faster and higher scalability compared to present electronic devices. A spintronic device is based on the transport of an electron's spin instead of charge. Efficient spin injection is one of the very important requirements for future spintronic devices. However, the effective spin injection is an exceedingly difficult task. In this paper, the importance of spin injection, basics of spin current and the essential requirements of spin injection are illustrated. The experimental technique of electrical spin injection into semiconductor is also discussed based on the experimental experience. The electrical spin injection can easily be implemented for spin injection into any semiconductor. (author)

  16. Compound semiconductor optical waveguide switch

    Science.gov (United States)

    Spahn, Olga B.; Sullivan, Charles T.; Garcia, Ernest J.

    2003-06-10

    An optical waveguide switch is disclosed which is formed from III-V compound semiconductors and which has a moveable optical waveguide with a cantilevered portion that can be bent laterally by an integral electrostatic actuator to route an optical signal (i.e. light) between the moveable optical waveguide and one of a plurality of fixed optical waveguides. A plurality of optical waveguide switches can be formed on a common substrate and interconnected to form an optical switching network.

  17. Dry etching technology for semiconductors

    CERN Document Server

    Nojiri, Kazuo

    2015-01-01

    This book is a must-have reference to dry etching technology for semiconductors, which will enable engineers to develop new etching processes for further miniaturization and integration of semiconductor integrated circuits.  The author describes the device manufacturing flow, and explains in which part of the flow dry etching is actually used. The content is designed as a practical guide for engineers working at chip makers, equipment suppliers and materials suppliers, and university students studying plasma, focusing on the topics they need most, such as detailed etching processes for each material (Si, SiO2, Metal etc) used in semiconductor devices, etching equipment used in manufacturing fabs, explanation of why a particular plasma source and gas chemistry are used for the etching of each material, and how to develop etching processes.  The latest, key technologies are also described, such as 3D IC Etching, Dual Damascene Etching, Low-k Etching, Hi-k/Metal Gate Etching, FinFET Etching, Double Patterning ...

  18. Ballistic superconductivity in semiconductor nanowires

    Science.gov (United States)

    Zhang, Hao; Gül, Önder; Conesa-Boj, Sonia; Nowak, Michał P.; Wimmer, Michael; Zuo, Kun; Mourik, Vincent; de Vries, Folkert K.; van Veen, Jasper; de Moor, Michiel W. A.; Bommer, Jouri D. S.; van Woerkom, David J.; Car, Diana; Plissard, Sébastien R; Bakkers, Erik P.A.M.; Quintero-Pérez, Marina; Cassidy, Maja C.; Koelling, Sebastian; Goswami, Srijit; Watanabe, Kenji; Taniguchi, Takashi; Kouwenhoven, Leo P.

    2017-01-01

    Semiconductor nanowires have opened new research avenues in quantum transport owing to their confined geometry and electrostatic tunability. They have offered an exceptional testbed for superconductivity, leading to the realization of hybrid systems combining the macroscopic quantum properties of superconductors with the possibility to control charges down to a single electron. These advances brought semiconductor nanowires to the forefront of efforts to realize topological superconductivity and Majorana modes. A prime challenge to benefit from the topological properties of Majoranas is to reduce the disorder in hybrid nanowire devices. Here we show ballistic superconductivity in InSb semiconductor nanowires. Our structural and chemical analyses demonstrate a high-quality interface between the nanowire and a NbTiN superconductor that enables ballistic transport. This is manifested by a quantized conductance for normal carriers, a strongly enhanced conductance for Andreev-reflecting carriers, and an induced hard gap with a significantly reduced density of states. These results pave the way for disorder-free Majorana devices. PMID:28681843

  19. Radiation tolerance of amorphous semiconductors

    International Nuclear Information System (INIS)

    Nicolaides, R.V.; DeFeo, S.; Doremus, L.W.

    1976-01-01

    In an attempt to determine the threshold radiation damage in amorphous semiconductors, radiation tests were performed on amorphous semiconductor thin film materials and on threshold and memory devices. The influence of flash x-rays and neutron radiation upon the switching voltages, on- and off-state characteristics, dielectric response, optical transmission, absorption band edge and photoconductivity were measured prior to, during and following irradiation. These extensive tests showed the high radiation tolerance of amorphous semiconductor materials. Electrical and optical properties, other than photoconductivity, have a neutron radiation tolerance threshold above 10 17 nvt in the steady state and 10 14 nvt in short (50 μsec to 16 msec) pulses. Photoconductivity increases by 1 1 / 2 orders of magnitude at the level of 10 14 nvt (short pulses of 50 μsec). Super flash x-rays up to 5000 rads (Si), 20 nsec, do not initiate switching in off-state samples which are voltage biased up to 90 percent of the threshold voltage. Both memory and threshold amorphous devices are capable of switching on and off during nuclear radiation transients at least as high as 2 x 10 14 nvt in 50 μsec pulses

  20. Thienoacene-based organic semiconductors.

    Science.gov (United States)

    Takimiya, Kazuo; Shinamura, Shoji; Osaka, Itaru; Miyazaki, Eigo

    2011-10-11

    Thienoacenes consist of fused thiophene rings in a ladder-type molecular structure and have been intensively studied as potential organic semiconductors for organic field-effect transistors (OFETs) in the last decade. They are reviewed here. Despite their simple and similar molecular structures, the hitherto reported properties of thienoacene-based OFETs are rather diverse. This Review focuses on four classes of thienoacenes, which are classified in terms of their chemical structures, and elucidates the molecular electronic structure of each class. The packing structures of thienoacenes and the thus-estimated solid-state electronic structures are correlated to their carrier transport properties in OFET devices. With this perspective of the molecular structures of thienoacenes and their carrier transport properties in OFET devices, the structure-property relationships in thienoacene-based organic semiconductors are discussed. The discussion provides insight into new molecular design strategies for the development of superior organic semiconductors. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.