Nuclear Fragmentation Reactions: from Basic Research to Medical Applications Igor N
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Lawrence Bragg's “Brainwave” Drives Father-Son Collaboration
www.mrs.org/publications/bulletin HISTORICAL NOTE Lawrence Bragg’s “Brainwave” Drives Father-Son Collaboration In 1912, some 17 years after the serendip- and quickly began to learn what he could itous discovery of x-rays by Wilhelm on the subject. Röntgen, a debate raged as to the wave or Until this point in his life, at age 42, particle nature of this radiation phenome- William later recalled, “It had never non. William Henry Bragg, a 50-year-old entered my head that I should do any professor of physics at Leeds University in research work.” His curiosity aroused by England, came down firmly on the side of his reading on radiation, he soon obtained particles, citing the bullet-like nature of the some radium samples and began the rays, and how they were preferentially experiments that were to make him a lead- scattered in the forward direction when ing figure in radiation theory in a few colliding with matter. Max von Laue of years’ time. He quickly developed novel Germany, having produced elegant spot- hypotheses about the nature of radioactiv- diffraction photographs of CuS by aiming ity. The penetrating power of x-rays, and x-rays at crystal samples, used the diffrac- the fact that they are not deflected by a tion behavior as evidence for the wave magnetic field, were accounted for by the argument. Experiments by Charles G. “neutral pair hypothesis,” which stated Barkla that demonstrated the polarization that x-rays consisted of “an electron which of x-rays confirmed the wave theory in the has assumed a cloak of darkness in the minds of many scientists. -
1 X-Ray Diffraction Masatsugu Sei Suzuki Department Of
x-ray diffraction Masatsugu Sei Suzuki Department of Physics, SUNY at Binghamton (Date: January 13, 2012) Sir William Henry Bragg OM, KBE, PRS] (2 July 1862 – 10 March 1942) was a British physicist, chemist, mathematician and active sportsman who uniquely shared a Nobel Prize with his son William Lawrence Bragg - the 1915 Nobel Prize in Physics. The mineral Braggite is named after him and his son. http://en.wikipedia.org/wiki/William_Henry_Bragg ________________________________________________________________________ Sir William Lawrence Bragg CH OBE MC FRS (31 March 1890 – 1 July 1971) was an Australian-born British physicist and X-ray crystallographer, discoverer (1912) of the Bragg law of X-ray diffraction, which is basic for the determination of crystal structure. He was joint winner (with his father, Sir William Bragg) of the Nobel Prize for Physics in 1915. http://en.wikipedia.org/wiki/William_Lawrence_Bragg 1 1. x-ray source Fig. Schematic diagram for the generation of x-rays. Metal target (Cu or Mo) is bombarded by accelerating electrons. The power of the system is given by P = I(mA) V(keV), where I is the current of cathode and V is the voltage between the anode and cathode. Typically, we have I = 30 mA and V = 50 kV: P = 1.5 kW. We use two kinds of targets to generate x-rays: Cu and Mo. The wavelength of CuK1, CuK2 and CuK lines are given by K1 1.540562 Å. K 2 = 1.544390 Å, K = 1.392218 Å. The intensity ratio of CuK1 and CuK2 lines is 2:1. The weighed average wavelength K is calculated as 2 K 1 K 2 = 1.54184 Å. -
Lsu-Physics Iq Test 3 Strikes You're
LSU-PHYSICS IQ TEST 3 STRIKES YOU'RE OUT For Physics Block Party on 9 September 2016: This was run where all ~70 people start answering each question, given out one-by-one. Every time a person missed an answer, they made a 'strike'. All was done with the Honor System for answers, plus a fairly liberal statement of what constitutes a correct answer. When the person accumulates three strikes, then they are out of the game. The game continue until only one person was left standing. Actually, there had to be one extra question to decide a tie-break between 2nd and 3rd place. The prizes were: FIRST PLACE: Ravi Rau, selecting an Isaac Newton 'action figure' SECOND PLACE: Juhan Frank, selecting an Albert Einstein action figure THIRD PLACE: Siddhartha Das, winning a Mr. Spock action figure. 1. What is Einstein's equation relating mass and energy? E=mc2 OK, I knew in advance that someone would blurt out the answer loudly, and this did happen. So this was a good question to make sure that the game flowed correctly. 2. What is the short name for the physics paradox depicted on the back of my Physics Department T-shirt? Schroedinger's Cat 3. Give the name of one person new to our Department. This could be staff, student, or professor. There are many answers, for example with the new profs being Tabatha Boyajian, Kristina Launey, Manos Chatzopoulos, and Robert Parks. Many of the people asked 'Can I just use myself?', with the answer being "Sure". 4. What Noble Gas is named after the home planet of Kal-El? Krypton. -
Absolute Zero, Absolute Temperature. Absolute Zero Is the Lowest
Contents Radioactivity: The First Puzzles................................................ 1 The “Uranic Rays” of Henri Becquerel .......................................... 1 The Discovery ............................................................... 2 Is It Really Phosphorescence? .............................................. 4 What Is the Nature of the Radiation?....................................... 5 A Limited Impact on Scientists and the Public ............................ 6 Why 1896? .................................................................. 7 Was Radioactivity Discovered by Chance? ................................ 7 Polonium and Radium............................................................. 9 Marya Skłodowska .......................................................... 9 Pierre Curie .................................................................. 10 Polonium and Radium: Pierre and Marie Curie Invent Radiochemistry.. 11 Enigmas...................................................................... 14 Emanation from Thorium ......................................................... 17 Ernest Rutherford ........................................................... 17 Rutherford Studies Radioactivity: ˛-and ˇ-Rays.......................... 18 ˇ-Rays Are Electrons ....................................................... 19 Rutherford in Montreal: The Radiation of Thorium, the Exponential Decrease........................................... 19 “Induced” and “Excited” Radioactivity .................................... 20 Elster -
William Henry Bragg 1862 - 1942 Awarded the Nobel Prize for Physics in 1915
William Henry Bragg 1862 - 1942 Awarded the Nobel Prize for Physics in 1915 William Henry Bragg was a pioneer British scientist in solid- state physics. He was born on July 2, 1862, in Wigton, Cumberland, England. Bragg's father came from a family of farmers and merchant seamen. His mother, a sweet and kind woman, was the daughter of the local vicar. He did not remember her very well, as she died when he was about seven. The small boy was taken to the family of his uncle, the owner of a pharmacy and grocery shop. In 1875 his father took him back and sent him to school at King William’s College, Isle of Man. Bragg was good in his lessons and sports and became the head boy. He was fond of all games and played them rather well. In 1881 Bragg tried for Cambridge University,but the first interview was not a success, and he had to return to school.After the next attempt he was granted a scholarship to Trinity College. Here he worked very hard at mathematics and two years later obtained third place in the final Both he and his son examination. Bragg played tennis and hockey well. His teacher was the famous physicist J.J. lectured at the Royal Thomson with whom he also played tennis. Thomson advised him to send an application for the Institution post of professor of mathematics and physics at Adelaide University in Australia. After an interview Bragg was appointed and went to Australia where he began his career. In Adelaide the young professor became one of the best lecturers and a brilliant experimentalist. -
Lawrence Bragg's
www.mrs.org/publications/bulletin HISTORICAL NOTE Lawrence Bragg’s “Brainwave” Drives Father-Son Collaboration In 1912, some 17 years after the serendip- and quickly began to learn what he could itous discovery of x-rays by Wilhelm on the subject. Röntgen, a debate raged as to the wave or Until this point in his life, at age 42, particle nature of this radiation phenome- William later recalled, “It had never non. William Henry Bragg, a 50-year-old entered my head that I should do any professor of physics at Leeds University in research work.” His curiosity aroused by England, came down firmly on the side of his reading on radiation, he soon obtained particles, citing the bullet-like nature of the some radium samples and began the rays, and how they were preferentially experiments that were to make him a lead- scattered in the forward direction when ing figure in radiation theory in a few colliding with matter. Max von Laue of years’ time. He quickly developed novel Germany, having produced elegant spot- hypotheses about the nature of radioactiv- diffraction photographs of CuS by aiming ity. The penetrating power of x-rays, and x-rays at crystal samples, used the diffrac- the fact that they are not deflected by a tion behavior as evidence for the wave magnetic field, were accounted for by the argument. Experiments by Charles G. “neutral pair hypothesis,” which stated Barkla that demonstrated the polarization that x-rays consisted of “an electron which of x-rays confirmed the wave theory in the has assumed a cloak of darkness in the minds of many scientists. -
Who Got Moseley's Prize?
Chapter 4 Who Got Moseley’s Prize? Virginia Trimble1 and Vera V. Mainz*,2 1Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92697-4575, United States 2Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61802, United States *E-mail: [email protected]. Henry Gwyn Jeffreys Moseley (1887-1915) made prompt and very skilled use of the then new technique of X-ray scattering by crystals (Bragg scattering) to solve several problems about the periodic table and atoms. He was nominated for both the chemistry and physics Nobel Prizes by Svante Arrhenius in 1915, but was dead at Gallipoli before the committees finished their deliberations. Instead, the 1917 physics prize (announced in 1918 and presented on 6 June 1920) went to Charles Glover Barkla (1877-1944) “for discovery of the Röntgen radiation of the elements.” This, and his discovery of X-ray polarization, were done with earlier techniques that he never gave up. Moseley’s contemporaries and later historians of science have written that he would have gone on to other major achievements and a Nobel Prize if he had lived. In contrast, after about 1916, Barkla moved well outside the scientific mainstream, clinging to upgrades of his older methods, denying the significance of the Bohr atom and quantization, and continuing to report evidence for what he called the J phenomenon. This chapter addresses the lives and scientific endeavors of Moseley and Barkla, something about the context in which they worked and their connections with other scientists, contemporary, earlier, and later. © 2017 American Chemical Society Introduction Henry Moseley’s (Figure 1) academic credentials consisted of a 1910 Oxford BA with first-class honors in Mathematical Moderations and a second in Natural Sciences (physics) and the MA that followed more or less automatically a few years later. -
Newsletter, November 2017
ISSN 1756-168X (Print) ISSN 2516-3353 (Online) Newsletter No. 35 November 2017 Published by the History of Physics Group of the Institute of Physics (UK & Ireland) ISSN 1756-168X IOP History of Physics Newsletter November 2017 Contents Editorial 2 Meeting Reports Chairman’s Report 3 Rutherford’s chemists - abstracts 5 ‘60 Years on from ZETA’ by Chris Warrick 10 Letters to the editor 13 Obituary John W Warren by Stuart Leadstone 15 Features Anti-matter or anti-substance? by John W Warren 16 A Laboratory in the Clouds - Horace-Bénédict de Saussure by Peter Tyson 18 On Prof. W.H.Bragg’s December 1914 Letter to the Vice- Chancellor of the University of Leeds by Chris Hammond 34 Book Reviews Crystal Clear - Autobiographies of Sir Lawrence and Lady Bragg by Peter Ford 54 Forthcoming Meetings 69 Committee and contacts 70 61 2 Editorial A big ‘Thank you’! Around 45 people attended the Bristol meeting on the History of Particle Colliders, in April. It was a joint meeting between the History of Physics Group, the High Energy Physics Group, and the Particle Accelerators and Beams Group. With a joint membership of around 2000, that works out at well under 3% - and that was a good turnout. The Rutherford’s Chemists meeting held in Glasgow attracted probably a similar percentage - not very high you might think. But time and travel costs to attend come at a premium so any means by which the content of our meetings may be promulgated - reports in our newsletter and in those of the other groups - is a very worthwhile task. -
April 8-11, 2019 the 2019 Franklin Institute Laureates the 2019 Franklin Institute AWARDS CONVOCATION APRIL 8–11, 2019
april 8-11, 2019 The 2019 Franklin Institute Laureates The 2019 Franklin Institute AWARDS CONVOCATION APRIL 8–11, 2019 Welcome to The Franklin Institute Awards, the range of disciplines. The week culminates in a grand oldest comprehensive science and technology medaling ceremony, befitting the distinction of this awards program in the United States. Each year, the historic awards program. Institute recognizes extraordinary individuals who In this convocation book, you will find a schedule of are shaping our world through their groundbreaking these events and biographies of our 2019 laureates. achievements in science, engineering, and business. We invite you to read about each one and to attend We celebrate them as modern day exemplars of our the events to learn even more. Unless noted otherwise, namesake, Benjamin Franklin, whose impact as a all events are free and open to the public and located scientist, inventor, and statesman remains unmatched in Philadelphia, Pennsylvania. in American history. Along with our laureates, we honor Franklin’s legacy, which has inspired the We hope this year’s remarkable class of laureates Institute’s mission since its inception in 1824. sparks your curiosity as much as they have ours. We look forward to seeing you during The Franklin From shedding light on the mechanisms of human Institute Awards Week. memory to sparking a revolution in machine learning, from sounding the alarm about an environmental crisis to making manufacturing greener, from unlocking the mysteries of cancer to developing revolutionary medical technologies, and from making the world III better connected to steering an industry giant with purpose, this year’s Franklin Institute laureates each reflect Ben Franklin’s trailblazing spirit. -
Scientists and War 1916-2016 by Dave Webb Leeds Beckett University and Scientists for Global Responsibility
Scientists and War 1916-2016 By Dave Webb Leeds Beckett University and Scientists for Global Responsibility The quest for understanding and to know how things work – to find out why they are, what they are - has always been a major driving force for scientists. There are, however, other more negative external drivers – such as the pursuit for military superiority, even in times of peace. Science and engineering have unfortunately made killing easier by helping to develop new types of weapons and World War 1 saw more than its fair share of those. The war also saw a mixture of attitudes from scientists and engineers. Many thought it their duty to help develop new weapons technologies. But there were also those who would not participate in the killing. To understand the social pressures on scientists who spoke out against the war, we need to recognise the cultural context at that time. Just before World War 2 an article in Time magazine dated 11 September 1939, entitled Science and War, expressed the opinion that scientists were not to blame for the way in which their discoveries were used by “men of bad will” and misapplied to “the conquest and murder of men”. This also seemed to be the attitude of many scientists in 1914, and perhaps remains so today. Some though were directly involved. At the outbreak of the First World War, men with specialist scientific and technological skills were not prevented from serving at the Front – by Germany or the Allies. Although some were placed into departments of Time Magazine Front Cover, the armed forces where their skills could be used – for example September 11, 1939 Physicists Ernest Rutherford (Professor of Physics at Manchester since 1907 and winner of the 1908 Nobel Prize in Chemistry) and William Henry Bragg (holder of the Cavendish chair of physics at Leeds since 1909) went to carry out anti-submarine work for the Admiralty. -
Nobel Prizes in Physics Closely Connected with the Physics of Solids
Nobel Prizes in Physics Closely Connected with the Physics of Solids 1901 Wilhelm Conrad Röntgen, Munich, for the discovery of the remarkable rays subsequently named after him 1909 Guglielmo Marconi, London, and Ferdinand Braun, Strassburg, for their contributions to the development of wireless telegraphy 1913 Heike Kamerlingh Onnes, Leiden, for his investigations on the properties of matter at low temperatures which lead, inter alia, to the production of liquid helium 1914 Max von Laue, Frankfort/Main, for his discovery of the diffraction of X-rays by crystals 1915 William Henry Bragg, London, and William Lawrence Bragg, Manchester, for their analysis of crystal structure by means of X-rays 1918 Max Planck, Berlin, in recognition of the services he rendered to the advancement of Physics by his discovery of energy quanta 1920 Charles Edouard Guillaume, Sèvres, in recognition of the service he has rendered to precise measurements in Physics by his discovery of anoma- lies in nickel steel alloys 1921 Albert Einstein, Berlin, for services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect 1923 Robert Andrews Millikan, Pasadena, California, for his work on the ele- mentary charge of electricity and on the photo-electric effect 1924 Manne Siegbahn, Uppsala, for his discoveries and researches in the field of X-ray spectroscopy 1926 Jean Baptiste Perrin, Paris, for his work on the discontinuous structure of matter, and especially for his discovery of sedimentation equilibrium 1928 Owen Willans Richardson, London, for his work on the thermionic phe- nomenon and especially for his discovery of the law named after him 1929 Louis Victor de Broglie, Paris, for his discovery of the wave nature of electrons 1930 Venkata Raman, Calcutta, for his work on the scattering of light and for the discovery of the effect named after him © Springer International Publishing Switzerland 2015 199 R.P. -
Main Attributes of Nuclides Presented in This Book
Appendix A Main Attributes of Nuclides Presented in This Book Data given in TableA.1 can be used to determine the various decay energies for the specific radioactive decay examples as well as for the nuclear activation examples presented in this book. M stands for the nuclear rest mass; M stands for the atomic rest mass. The data were obtained from the NIST and are based on CODATA 2010 as follows: 1. Data for atomic masses M are given in atomic mass constants u and were obtained from the NIST at: (http://www.physics.nist.gov/pml/data/comp.cfm). 2. Rest mass of proton mp, neutron mn, electron me, and of the atomic mass constant u are from the NIST (http://www.physics.nist.gov/cuu/constants/index. html) as follows: −27 2 mp = 1.672 621 777×10 kg = 1.007 276 467 u = 938.272 046 MeV/c (A.1) −27 2 mn = 1.674 927 351×10 kg = 1.008 664 916 u = 939.565 379 MeV/c (A.2) −31 −4 2 me = 9.109 382 91×10 kg = 5.485 799 095×10 u = 0.510 998 928 MeV/c (A.3) − 1u= 1.660 538 922×10 27 kg = 931.494 060 MeV/c2 (A.4) 3. For a given nuclide, its nuclear rest energy was determined by subtracting the 2 rest energy of all atomic orbital electrons (Zmec ) from the atomic rest energy M(u)c2 as follows 2 2 2 Mc = M(u)c − Zmec = M(u) × 931.494 060 MeV/u − Z × 0.510 999 MeV.