Karl K. Darrow

Bio: Karl K. Darrow is an academic researcher. The author has contributed to research in topics: Resonance & Magnetic field. The author has an hindex of 5, co-authored 22 publications receiving 210 citations.

Nuclear fission

Abstract: This article pertains to the most newly-discovered and most sensational mode of transmutation, in which the entry of a neutron into a massive atom-nucleus brings about an internal explosion in which the nucleus is “fissured” or divided into two fragments which share the total mass and charge between them in nearly equal proportions, (In all other modes of transmutation except those affecting the very lightest elements, the division is into fragments of very unequal mass and charge.) The conversion of rest-mass into kinetic energy, or (as is more commonly said) the release of energy, is unprecedented in scale. A multitude of radioactive bodies, many hitherto unknown, is formed; and there is spontaneous emission of fresh neutrons in great quantities, possibly sufficient to convert the process once initiated into a self-perpetuating one under realizable conditions.

Magnetic resonance: Part I — Nuclear magnetic resonance

Abstract: Magnetic resonance is the name of a phenomenon discovered less than sixteen years ago, which from the start has had a high theoretical importance and is now attaining a notable practical valve. Nuclear magnetic resonance occurs when a substance containing magnetic nuclei is exposed to crossed magnetic fields, one being steady and the other oscillating, and the strength of the former field and the frequency of the latter are matched in a particular way. When these are properly matched, the nuclei are turned over in the steady field, and energy is absorbed from the oscillating field. Another way of describing the effect is to say that resonance occurs when the applied frequency is equal to the frequency of precession of the nuclei in the steady field. This phenomenon illustrates very clearly some of the fundamental laws of Nature. For the purposes of nuclear physics it is used to determine the magnetic moments of nuclei and their relaxation-times in the substance that contains them. It is also used for chemical analysis, for measurement of magnetic fields, for analysis of crystal structure and for locating changes of phase of the substance containing the nuclei. Magnetic resonance of electrons is similar, but for a fundamental reason is confined almost exclusively to free atoms of certain kinds, to ferromagnetic substances and to certain strongly paramagnetic salts. For these last it serves to throw light on the fields prevailing within the crystals.

Contemporary advances in physics, XXIV high-frequency phenomena in gases, first part

Abstract: This is an account of the behavior of conducting gases subjected to high-frequency electrostatic fields — behavior which can be interpreted, in many cases with striking success, by supposing that the free electrons wandering in the gas are set into motion by the field, and oscillate and drift according to laws which can be derived from our knowledge of the response of free electrons to steady fields. When a constant magnetic field coexists with the high-frequency forces, the phenomena become more complicated, but remain predictable. There are also peculiar phenomena indicating that the electrons in a conductive gas have certain natural frequencies of oscillation. Applications are made to the absorption of radio-frequency waves in ionized gases.

Contemporary advances in physics, XXVI the nucleus, first part

Abstract: This article, like its forerunners on radioactivity and transmutation, is devoted to the beginnings of the oncoming stage of atomic physics: the study of the nucleus. The nucleus or kernel of an atom is in ultimate control of all its properties and features, for such of these as do not depend directly on it depend upon the number and arrangement of the orbital electrons, both of which are decided by the nuclear charge; further, the atomic weight is decided almost exclusively by the nuclear mass. Though in dealing with most of these properties it is usual to imagine the nucleus as a geometrical point endowed with mass and charge, the truth is far less simple and more interesting. Nuclei are structures built of elementary particles — some and maybe all of which are independently known to us — bound tightly together. It is of great importance to ascertain these structures, not only for their own sake, but because through understanding them we may become able to control and extend the transformations of nuclei from one kind to another — the processes of transmutation, some of which are already feasible. Several fields of research are apt to contribute to such an understanding. Accurate measurement of the masses of atoms, and of the masses and charges and other properties of the elementary particles, are the first two of these, and form the subject of the present article.

Contemporary Advances in Physics, XVI

Abstract: This is an elementary introduction to the phenomena of diffraction of waves by crystals, one of the most striking and important discoveries of the last twenty years of physics. These phenomena have proved that X-rays and electrons are partly of the nature of waves, and have supplied the best available methods of measuring their wave-lengths; while on the other hand, the study of the diffraction-pattern of a crystalline substance makes it possible to determine the arrangement and the interrelations of the atoms with a precision and fullness heretofore unimagined, which has already yielded knowledge of great value in all the fields of science and promises immeasurably more.

Practical Electronics for Inventors

Abstract: THE BOOK THAT MAKES ELECTRONICS MAKE SENSE This intuitive, applications-driven guide to electronics for hobbyists, engineers, and students doesn't overload readers with technical detail. Instead, it tells you-and shows you-what basic and advanced electronics parts and components do, and how they work. Chock-full of illustrations, Practical Electronics for Inventors offers over 750 hand-drawn images that provide clear, detailed instructions that can help turn theoretical ideas into real-life inventions and gadgets. CRYSTAL CLEAR AND COMPREHENSIVE Covering the entire field of electronics, from basics through analog and digital, AC and DC, integrated circuits (ICs), semiconductors, stepper motors and servos, LCD displays, and various input/output devices, this guide even includes a full chapter on the latest microcontrollers. A favorite memory-jogger for working electronics engineers, Practical Electronics for Inventors is also the ideal manual for those just getting started in circuit design. If you want to succeed in turning your ideas into workable electronic gadgets and inventions, is THE book. Starting with a light review of electronics history, physics, and math, the book provides an easy-to-understand overview of all major electronic elements, including: Basic passive components o Resistors, capacitors, inductors, transformers o Discrete passive circuits o Current-limiting networks, voltage dividers, filter circuits, attenuators o Discrete active devices o Diodes, transistors, thrysistors o Microcontrollers o Rectifiers, amplifiers, modulators, mixers, voltage regulators ENTHUSIASTIC READERS HELPED US MAKE THIS BOOK EVEN BETTER This revised, improved, and completely updated second edition reflects suggestions offered by the loyal hobbyists and inventors who made the first edition a bestseller. Reader-suggested improvements in this guide include: Thoroughly expanded and improved theory chapter New sections covering test equipment, optoelectronics, microcontroller circuits, and more New and revised drawings Answered problems throughout the book Practical Electronics for Inventors takes you through reading schematics, building and testing prototypes, purchasing electronic components, and safe work practices. You'll find all thisin a guide that's destined to get your creative-and inventive-juices flowing. Table of contents Chapter 1: Introduction to Electronics Chapter 2: Theory Chapter 3: Basic Electronic Circuit Components Chapter 4: Semiconductors Chapter 5: Optoelectronics Chapter 6: Integrated Circuits Chapter 7: Operational Amplifiers Chapter 8: Filters Chapter 9: Oscillators and Timers Chapter 10: Voltage Regulators and Power Supplies Chapter 11: Audio Electronics Chapter 12: Digital Electronics Chapter 13: DC Motors, RC Servos, and Stepper Motors Chapter 14: Hands-on Electronics Appendix A: Power Distribution and Home Wiring Appendix B: Error Analysis Appendix C: Useful Facts and Formulas Appendix D: Component Data, List of Logic ICs, Foreign Semiconductor Codes Appendix E: Microcontroller Circuits Index

Nuclear fission: a review of experimental advances and phenomenology.

Abstract: In the last two decades, through technological, experimental and theoretical advances, the situation in experimental fission studies has changed dramatically. With the use of advanced production and detection techniques both much more detailed and precise information can now be obtained for the traditional regions of fission research and, crucially, new regions of nuclei have become routinely accessible for fission studies. This work first of all reviews the recent developments in experimental fission techniques, in particular the resurgence of transfer-induced fission reactions with light and heavy ions, the emerging use of inverse-kinematic approaches, both at Coulomb and relativistic energies, and of fission studies with radioactive beams. The emphasis on the fission-fragment mass and charge distributions will be made in this work, though some of the other fission observables, such as prompt neutron and γ-ray emission will also be reviewed. A particular attention will be given to the low-energy fission in the so far scarcely explored nuclei in the very neutron-deficient lead region. They recently became the focus for several complementary experimental studies, such as β-delayed fission with radioactive beams at ISOLDE(CERN), Coulex-induced fission of relativistic secondary beams at FRS(GSI), and several prompt fusion-fission studies. The synergy of these approaches allows a unique insight in the new region of asymmetric fission around 180Hg, recently discovered at ISOLDE. Recent extensive theoretical efforts in this region will also be outlined. The unprecedented high-quality data for fission fragments, completely identified in Z and A, by means of reactions in inverse kinematics at FRS(GSI) and VAMOS(GANIL) will be also reviewed. These experiments explored an extended range of mercury-to-californium elements, spanning from the neutron-deficient to neutron-rich nuclides, and covering both asymmetric, symmetric and transitional fission regions. Some aspects of heavy-ion induced fusion-fission and quasifission reactions will be also discussed, which reveal their dynamical features, such as the fission time scale. The crucial role of the multi-chance fission, probed by means of multinucleon-transfer induced fission reactions, will be highlighted. The review will conclude with the discussion of the new experimental fission facilities which are presently being brought into operation, along with promising 'next-generation' fission approaches, which might become available within the next decade.

Self-consistent calculations of fission barriers in the Fm region

Abstract: The fission barriers of the nuclei ${}^{254}\mathrm{Fm},$ ${}^{256}\mathrm{Fm},$ ${}^{258}\mathrm{Fm},$ ${}^{258}\mathrm{No}$, and ${}^{260}\mathrm{Rf}$ are investigated in a fully microscopic way up to the scission point. The analysis is based on the constrained Hartree-Fock-Bogoliubov theory and Gogny's D1S force. The quadrupole, octupole, and hexadecapole moments as well as the number of nucleons in the neck region are used as constraints. Two fission paths, corresponding to the bimodal fission, are found. The decrease with isotope mass of the half-life times of heavy Fm isotopes is also explained.