1-W, high-repetition-rate room temperature operation of mid-infrared optical parametric oscillator based on periodically poled MgO-doped LiNbO

In this paper a high-repetition-rate mid-infrared （mid-IR） optical parametric oscillator based on periodically poled MgO-doped LiNbO3 （PPMgLN） at room temperature was demonstrated. The maximum average mid-IR output power at 3.63μm was 1.02 W with the repetition rate of 60kHz and corresponding efficiency from the pump to the idler was 26.7%. The temperature tuning and the period tuning characteristics were also discussed.     

Waves,waves, and more waves

Institute of Applied Physics, Russian Academy of Sciences. Edited from Izvetiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 36, No. 7, pp. 576–587, July, 1993.     

Effect of chromium on structure,strength, and plasticity of high-temperature intermetallide Ni3Al

The effect of chromium on structure, strength characteristics, plasticity, and failure principles in the polycrystalline intermetallide Ni₃Al, produced by self-propagating high-temperature synthesis, is studied over the temperature range 290–1270 K. It is shown that the effect of chromium depends upon which element (nickel or aluminum) it is introduced in place of, although failure of alloys with various chromium contents at all deformation temperatures remains intercrystallite in nature.V. D. Kuznetsov Siberian Physicotechnical Institute at Tomsk State University. Institute of Strength Physics and Materials Science, Siberian Branch, Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 30–36, June, 1993.     

Introduction to focus issue on "randomness, structure, and causality: measures of complexity from theory to applications"

We introduce the contributions to this Focus Issue and describe their origin in a recent Santa Fe Institute workshop.     

Diffraction-limited short-wavelength optics: Analysis, fabrication, and application

The fundamental physical and technological problems of fabrication and testing, as well as new optics applications providing diffraction-quality images (with spatial resolutions varying from tens of nanometers to several nanometers) at wavelengths of 3?C60 nm, are analyzed. This type of optical systems is required in the mass production of very large-scale integrated circuits (ICs) (projection nanolithography), nanocertification (high-resolution X-ray microscopy), macrodiagnosis (extraterrestrial astronomy), and in fundamental investigations of the interaction between a material (vacuum) and superstrong electromagnetic fields (10²⁰?10²³ W/cm²). The current state of interaction studies around the world has been reviewed. The latest developments implemented in this area at the Institute for Physics of Microstructures, Russian Academy of Sciences, have been discussed.     

Active,two-element,microwave interferometry of the sea surface

Institute of Radio Engineering and Electronics, Academy of Sciences of the USSR. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 31, No. 3, pp. 263–273, March, 1988.     

Science, Technology, and the Niels Bohr Institute in Occupied Denmark

I argue that research in the basic sciences during the German occupation of Denmark, which began on April 9, 1940, suffered considerably, while research and development in technology enjoyed improved conditions as Danish industry moved toward the requirements of the German wartime economy. Several organizations were created to further Danish–German scientific and cultural collaboration or to manifest Danish cultural identity. The staff of the Danish Technical College and the number of their publications remained largely constant although no papers appeared in British or American journals after 1941. Danish universities massively resisted collaboration and maintained an illusion of “business as usual.” At the Niels Bohr Institute, laboratory equipment continued to be constructed and developed and scientists continued to publish in Danish and other Scandinavian journals, although they were increasingly isolated owing to their inability to obtain foreign scientific journals and to correspond with foreign scientists. The Niels Bohr Institute was occupied from December 6, 1943, to February 3, 1944, a surprisingly short period, owing, I argue, to strategic compromises in following incompatible orders from the German army, security police, and civilian administration. Finally, I offer an interpretation of Niels Bohr’s vehemently negative reaction to Werner Heisenberg in their meeting in Copenhagen in September 1941.     

Paul Ehrenfest, Niels Bohr, and Albert Einstein: Colleagues and Friends

In May 1918 Paul Ehrenfest received a monograph from Niels Bohr in which Bohr had used Ehrenfest’s adiabatic principle as an essential assumption for understanding atomic structure. Ehrenfest responded by inviting Bohr, whom he had never met, to give a talk at a meeting in Leiden in late April 1919, which Bohr accepted; he lived with Ehrenfest, his mathematician wife Tatyana, and their young family for two weeks. Albert Einstein was unable to attend this meeting, but in October 1919 he visited his old friend Ehrenfest and his family in Leiden, where Ehrenfest told him how much he had enjoyed and profited from Bohr’s visit. Einstein first met Bohr when Bohr gave a lecture in Berlin at the end of April 1920, and the two immediately proclaimed unbounded admiration for each other as physicists and as human beings. Ehrenfest hoped that he and they would meet at the Third Solvay Conference in Brussels in early April 1921, but his hope was unfulfilled. Einstein, the only physicist from Germany who was invited to it in this bitter postwar atmosphere, decided instead to accompany Chaim Weizmann on a trip to the United States to help raise money for the new Hebrew University in Jerusalem. Bohr became so overworked with the planning and construction of his new Institute for Theoretical Physics in Copenhagen that he could only draft the first part of his Solvay report and ask Ehrenfest to present it, which Ehrenfest agreed to do following the presentation of his own report. After recovering his strength, Bohr invited Ehrenfest to give a lecture in Copenhagen that fall, and Ehrenfest, battling his deep-seated self-doubts, spent three weeks in Copenhagen in December 1921 accompanied by his daughter Tanya and her future husband, the two Ehrenfests staying with the Bohrs in their apartment in Bohr’s new Institute for Theoretical Physics. Immediately after leaving Copenhagen, Ehrenfest wrote to Einstein, telling him once again that Bohr was a prodigious physicist, and again expressing the hope that he soon would see both of them in Leiden.     

Imploding stars,shifting continents,and the inconstancy of matter

Two revolutionary concepts of the twentieth century—continental drift and the existence of superdense stars and black holes—had extended histories which ran in curious parallel for five decades. Between the wars each encountered a fierce and emotionally charged resistance which may have had a common psychological root. Each threatened man's instinctive faith in the permanence of matter.Work supported by Canadian Institute for Advanced Research and by NSERC of Canada.     

Surface tension,percolation, and roughening

We describe inequalities relating to the interface between coexisting phases of Ising ferromagnets. Some implications for the nature of the roughening transition are discussed.Supported by National Science Foundation Grant No. MCS78-01885 at Princeton University and No. PHYS78-15920 at Rutgers University.Part of this work was done while Jean Bricmont was at the Mathematics Department of Princeton University and Joel L. Lebowitz at the Institute for Advanced Study, Princeton.     

Production of an Intense, Well-Collimated Submillimeter Wave Beam and Its Application to Plasma Scattering Measurements

Intense submillimeter wavelength radiation (f=354 GHz, P=110 W) from Gyrotron FU II is converted into a well-collimated, linearly-polarized beam by a quasi-optical transmission line consisting of a quasi-optical antenna and several mirrors. The observed focusing of the beam agrees with calculations based on the Huygens equation. We have used this intense beam to study low frequency density fluctuations by plasma scattering in Compact Helical System (CHS) plasmas at the National Institute for Fusion Science.     

Discoveries made by physicists from the Institute of Theoretical and Experimental Physics (ITEP, Moscow) or with their participation and officially included in the state register of discoveries of the USSR

The 60th Anniversary of the Institute of Theoretical and Experimental Physics (ITEP, Moscow) Elementary Particles and Fields

Discoveries made by physicists from the Institute of Theoretical and Experimental Physics (ITEP, Moscow) or with their participation and officially included in the state register of discoveries of the USSR     

ISLAND, revisited

This paper is in answer to the comment on the GRG paper: Lockerbie N.A. Gen. Rel. Grav. 36, 593 (2004), made by A.V. Sanders, G.T. Gillies (ibid.). N. A. Lockerbie is a member of the STEP (Satellite Test of the Equivalence Principle) Science Study Team, and an Associate of the Institute for Gravitational Research at the University of Glasgow, Scotland, UK.     

Spectroscopic parameters of CHFCl2, CHClF2, C2F6, and C3F8 molecules

We investigate the IR spectra of solutions of R-21,-22,-116, and R-218 in liquid argon at 90K. The frequencies, half-widths, and absolute integral intensities of all of the absorption bands recorded are obtained and interpreted. Scientific-Research Institute of Physics, 1, Ul'yanovskaya Str., Petrodvorets, St. Petersburg, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 3, pp. 297–301, May–June, 1997.     

A study of the Co59(p,n) reaction atE p =5·75–6·39 MeV

In this paper the angular distribution of neutrons from the reaction Co⁵⁹(p, n) Ni⁵⁹ was measured for six energies of the protonE _p lying in an interval between 5·75 and 6·39 MeV. The analysis of these results showed that other mechanisms besides the compound nucleus mechanism play a role in the whole studied region ofE _p . Neither their relative contribution nor the exact mechanism were determined.The authors would like to express their gratitude to Prof. Dr. V. Petrílka for his constant interest in this experiment and to Mr. Kemének from the Nuclear Research Institute of the Czechoslovak Academy of Sciences for the calculation of the coefficients in Table I. We are also indebted to the entire cyclotron team of the Nuclear Research Institute for their perfect cooperation during the measurements and to a group of physicists of this department for having put at our disposal the majority of the apparatus used.     

Powerful pulsed electrophysical transformers from the Institute of High-Current Electronics,Siberian Branch of the Russian Academy of Sciences

Problems in the creation and exploitation of powerful pulsed electrophysical transformers, developed at the Institute of High-Current Electronics, Siberian Branch of the Russian Academy of Sciences, are discussed. The power of the largest installations is 2.5·10¹² W (pulsed). The small size, the outside location of the main components requiring maintenance, and the absence of large volumes of transformer oil make the pulsed transformers competitive with pulsed voltage generators. Institute of High-Current Electronics, Siberian Branch of the Russian Academy of Sciences. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 12, pp. 58–66, December, 1995.     

Thermoluminiscence and exoelectron emission of KCl phosphors,activated by mercury-like ions

An experimental investigation is made of thermostimulated electronic emission and luminescence in potassium halide crystals activated with mercury-like ions. These phosphors were excited with X-rays or ultra-violet light in the activator absorption bands. The transfer of activator excitation to the host lattice, the creation of colour centres by these processes and the mechanism of exoelectron emission are discussed.Physics and Astronomy Institute of the Estonian Academy of Sciences, Tartu, Est.S.S.R. The experimental part of the work was completed in October–November 1962, during H. Käämbre's stay at the Institute of Solid State Physics, Prague.     

Hans Bethe, My Teacher

I sketch my experiences with Hans Bethe (1906–2005) as a teacher at Cornell University, beginning with my doctoral studies in 1961 and continuing with my work with him on a quantum-mechanics textbook. Hans Bethe, My Teacher: Based on my talk at the Bethe Memorial,Aspen Center for Physics,Aspen,CO, in August 2006. Roman Jackiw: Roman Jackiw is Jerrold Zacharias Professor of Physics at the Massachusetts Institute of Technology.     

A Remark on Asymptotic Completeness for the Critical Nonlinear Klein-Gordon Equation

We give a short proof of asymptotic completeness and global existence for the cubic Nonlinear Klein-Gordon equation in one dimension. Our approach to dealing with the long range behavior of the asymptotic solution is by reducing it, in hyperbolic coordinates to the study of an ODE. Similar arguments extend to higher dimensions and other long range type nonlinear problems. Mathematics Subject Classifications (2000): 35L15, 74J30, 76B15 ★ Part of this work was done while H.L. was a Member of the Institute for Advanced Study, Princeton, supported by the NSF grant DMS-0111298 to the Institute. H.L. was also partially supported by the NSF Grant DMS-0200226. † Also a member of the Institute of Advanced Study, Princeton. Supported in part by NSF grant DMS-0100490.     

Scalar fields around a charged,rotating black hole

The scalar wave equation is separated in a Kerr-Newman geometry and some properties of the effective potential barrier are discussed. Stationary solutions for massless scalar fields are found explicitly.For the most part, this work was carried out in 1973, while Z. S. and M. . were students at the Faculty of Mathematics and Physics. At present, Z. S. is at the Department of Physics, The School of Mines, Ostrava, M. . — at the Institute of Physical Metallurgy, Brno.