Rutherford and the Nuclear Atom
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James Chadwick: Ahead of His Time
July 15, 2020 James Chadwick: ahead of his time Gerhard Ecker University of Vienna, Faculty of Physics Boltzmanngasse 5, A-1090 Wien, Austria Abstract James Chadwick is known for his discovery of the neutron. Many of his earlier findings and ideas in the context of weak and strong nuclear forces are much less known. This biographical sketch attempts to highlight the achievements of a scientist who paved the way for contemporary subatomic physics. arXiv:2007.06926v1 [physics.hist-ph] 14 Jul 2020 1 Early years James Chadwick was born on Oct. 20, 1891 in Bollington, Cheshire in the northwest of England, as the eldest son of John Joseph Chadwick and his wife Anne Mary. His father was a cotton spinner while his mother worked as a domestic servant. In 1895 the parents left Bollington to seek a better life in Manchester. James was left behind in the care of his grandparents, a parallel with his famous predecessor Isaac Newton who also grew up with his grandmother. It might be an interesting topic for sociologists of science to find out whether there is a correlation between children educated by their grandmothers and future scientific geniuses. James attended Bollington Cross School. He was very attached to his grandmother, much less to his parents. Nevertheless, he joined his parents in Manchester around 1902 but found it difficult to adjust to the new environment. The family felt they could not afford to send James to Manchester Grammar School although he had been offered a scholarship. Instead, he attended the less prestigious Central Grammar School where the teaching was actually very good, as Chadwick later emphasised. -
People and Things
People and things On 15 April, Haim Harari of the Weizmann Institute, Israel, was guest speaker at a symposium to mark 20 years of accelerator operation at the Paul Scherrer Institute, Maurice Jacob's roving camera caught Murray Villigen, Switzerland. Gell Mann in a London pub with the manu (Photo Armin Muller) script of his book 'The Quark and the Jaguar'. 20 years of PSI In April the Swiss Paul Scherrer Institute celebrated 20 years of accelerator operations. Originally built for particle research, these facilities now extend over a wide spectrum of applications, from molecular structure to cancer therapy. Each year over 400 visiting researchers make use of PSI particle beams. Meetings An international symposium on strangeness and quark matter will be held from 1-5 September in Crete, covering 1. strangeness and quark- gluon plasma, 2. strangeness con LAPP, Annecy, well known authority French Academy of Sciences densation, 3. strange astrophysics, 4. on non-Abelian gauge theories, and strangelets, 5. dedicated instrumen Michel Davier, long-time specialist in tation for strangeness and quark Among the new corresponding electron-positron collision physics matter. Information from the Secre members of the French Academy of and former Director of the Orsay tariat, University of Athens, Physics Sciences (Academie des Sciences Linear Accelerator Laboratory. Other Dept., Nuclear & Particle Physics de Paris) are Raymond Stora of new members are Alain Aspect, Division, Panepistimioupolis, Greece- 15771 Athens, tel. (30-1)7247502, 7243362, 7243143, fax (30- 1)7235089, email gvassils ©atlas, uoa.ariadne-t.gr At a special colloquium held at CERN on 20 April to mark Carlo Rubbia's 60th birthday and the tenth anniversary of his Nobel Prize award with Simon van der Meer, left to right - Canadian TRIUMF Laboratory Director and former UA1 co-spokesman Alan Astbury, LHC Project Director Lyn Evans, Carlo Rubbia, Director General Chris Llewellyn Smith, and former UA 1 co-spokesman John Dowel I. -
REPORTS on RESEARCH PL9800669 6.1 the NA48
114 Annual Report 1996 I REPORTS ON RESEARCH PL9800669 6.1 The NA48 experiment on direct CP violation by A.Chlopik, Z.Guzik, J.Nassalski, E.Rondio, M.Szleper and W.WisIicki The NA48 experiment [1] was built and tested on the kaon beam at CERN. It aims to measure the effect of direct violation of the combined CP transformation in two-pion decays of neutral kaons with precision of 0.1 permille. To perform such a measurement beams of the long-lived and short-lived Ks are produced which decay in the common region of phase space. Decays of both kaons into charged and neutral pions are measured simultaneously. The Warsaw group contributed to the electronics of the data acquisition system, to the offline software and took part in the data taking during test runs in June and September 1996. The hardware contribution of the group consisted of design, prototype manufacturing, testing and production supervision of the data acquisition blocks: RIO Fiber Optics Links, Cluster Interconnectors and Clock Fanouts. These elements are described in a separate note of this report. We worked on the following software related issues: (i) reconstruction of data and Monte Carlo in the magnetic spectrometer consisting of four drift chambers, the bending magnet and the trigger hodoscope. Energy and momentum resolution and background sources were carefully studied, (ii) decoding and undecoding of the liquid kryptonium calorimeter data. This part of the equipment is crucial for the measurement of neutral decays, (iii) correlated Monte Carlo to use the same events to simulate KL and K^ decays and thus speed up simulation considerably. -
Harry Moseley: Numbering the Elements
MYSTERY OF MATTER: SEARCH FOR THE ELEMENTS 5. Harry Moseley: Numbering the Elements Dmitri Mendeleev (identified on screen) works on the Periodic Table, writes down the atomic weights of the elements. NARR: Previously on The Mystery of Matter… HISTORIAN MICHAEL GORDIN VO He figures out something rather extraordinary about the elements. DMITRI MENDELEEV, partly in VO The eye is immediately struck by a pattern within the horizontal rows and the vertical columns. Mendeleev’s first table morphs into the familiar modern Periodic Table. AUTHOR ERIC SCERRI VO He found an absolutely fundamental principle of nature. Humphry Davy (identified on screen) performs an experiment with his voltaic pile. HISTORIAN DAVID KNIGHT VO Somehow the particles of matter have to be glued together to form molecules. What Davy has had is a big idea. Perhaps electricity could be this kind of glue. Marie Curie (identified on screen) sits down at the spectroscope and peers into the eyepiece. NARR: The spectroscope kicked off a whole new round in the discovery of elements. The spectra of four elements appear on screen, along with their names. PHYSICIST DAVID KAISER VO It’s almost like each element has its own bar code. Marie and Pierre enter their lab at night and see vials of radium glowing on the shelves. MARIE TO PIERRE Don’t light the lamps! Look! 1 MYSTERY OF MATTER: SEARCH FOR THE ELEMENTS PHYSICIST DAVID KAISER VO Radioactivity was a sign that the atom itself was unstable. It could break apart. Marie and Pierre look in wonder at their radiant element. NARR: Scientists now had a pressing new question to answer: What’s inside the atom? Fade to black ANNOUNCER: Major funding for The Mystery of Matter: Search for the Elements was provided by the National Science Foundation, where discoveries begin. -
Ernest Rutherford and the Accelerator: “A Million Volts in a Soapbox”
Ernest Rutherford and the Accelerator: “A Million Volts in a Soapbox” AAPT 2011 Winter Meeting Jacksonville, FL January 10, 2011 H. Frederick Dylla American Institute of Physics Steven T. Corneliussen Jefferson Lab Outline • Rutherford's call for inventing accelerators ("million volts in a soap box") • Newton, Franklin and Jefferson: Notable prefiguring of Rutherford's call • Rutherfords's discovery: The atomic nucleus and a new experimental method (scattering) • A century of particle accelerators AAPT Winter Meeting January 10, 2011 Rutherford’s call for inventing accelerators 1911 – Rutherford discovered the atom’s nucleus • Revolutionized study of the submicroscopic realm • Established method of making inferences from particle scattering 1927 – Anniversary Address of the President of the Royal Society • Expressed a long-standing “ambition to have available for study a copious supply of atoms and electrons which have an individual energy far transcending that of the alpha and beta particles” available from natural sources so as to “open up an extraordinarily interesting field of investigation.” AAPT Winter Meeting January 10, 2011 Rutherford’s wish: “A million volts in a soapbox” Spurred the invention of the particle accelerator, leading to: • Rich fundamental understanding of matter • Rich understanding of astrophysical phenomena • Extraordinary range of particle-accelerator technologies and applications AAPT Winter Meeting January 10, 2011 From Newton, Jefferson & Franklin to Rutherford’s call for inventing accelerators Isaac Newton, 1717, foreseeing something like quarks and the nuclear strong force: “There are agents in Nature able to make the particles of bodies stick together by very strong attractions. And it is the business of Experimental Philosophy to find them out. -
Radiation and Radioactivity Quantified? Do You Think of These “People” When I Say RADIATION? Do You Think of These Things As Well?
Welcome To RadTown USA •Click to Explore RadTown USA • Click on any location in RadTown USA and find out about radiation sources or uses at that location. The Alpha, Beta, Gammas of Nuclear Education March 2nd, 2014 Fundamentals of Ionizing Radiation Debra N Thrall, PhD Executive Director Albert I Pierce Foundation Radiation Fundamentals What is radiation? Where does it come from? How does it interact with matter? What is radioactivity? What are fission and fusion? How are radiation and radioactivity quantified? Do you think of these “people” when I say RADIATION? Do you think of these things as well? • Food • Space • Utilities • Consumer Products • Medicine Brief History of the Atom • 500 BC Democritus Atom • Long time (Romans Dark Ages) • 1808 AD Dalton Plum Pudding • 1911 Rutherford Nucleus • 1913 Bohr Orbits • 1920’s Many People Quantum Mechanics Rutherford’s Gold Foil Experiment The Design 1. Bombard positively charged alpha particles into thin gold foil. 2. Use fluorescent screen to detect particles as they exit the gold foil. 3. Use angle of deflection to determine interior of the atom. So, What is an Atom? • Atoms are made up of protons, neutrons & electrons • Protons: + charge p+ • Neutrons: no charge n0 • Electrons: - charge e- • Atoms want to have a stable energy level • This translates to having no net charge • # protons = # electrons Mass of an Atom • Masses • Proton: 1.000000 amu • Neutron: 1.000000 amu • Electron: 0.000549 amu (Translates to 1.2 lbs/1 ton ~ a kitten on an elephant!) • The mass of an atom is approximately -
6.2 Transition Radiation
Contents I General introduction 9 1Preamble 11 2 Relevant publications 15 3 A first look at the formation length 21 4 Formation length 23 4.1Classicalformationlength..................... 24 4.1.1 A reduced wavelength distance from the electron to the photon ........................... 25 4.1.2 Ignorance of the exact location of emission . ....... 25 4.1.3 ‘Semi-bare’ electron . ................... 26 4.1.4 Field line picture of radiation . ............... 26 4.2Quantumformationlength..................... 28 II Interactions in amorphous targets 31 5 Bremsstrahlung 33 5.1Incoherentbremsstrahlung..................... 33 5.2Genericexperimentalsetup..................... 35 5.2.1 Detectors employed . ................... 35 5.3Expandedexperimentalsetup.................... 39 6 Landau-Pomeranchuk-Migdal (LPM) effect 47 6.1 Formation length and LPM effect.................. 48 6.2 Transition radiation . ....................... 52 6.3 Dielectric suppression - the Ter-Mikaelian effect.......... 54 6.4CERNLPMExperiment...................... 55 6.5Resultsanddiscussion....................... 55 3 4 CONTENTS 6.5.1 Determination of ELPM ................... 56 6.5.2 Suppression and possible compensation . ........ 59 7 Very thin targets 61 7.1Theory................................ 62 7.1.1 Multiple scattering dominated transition radiation . .... 62 7.2MSDTRExperiment........................ 63 7.3Results................................ 64 8 Ternovskii-Shul’ga-Fomin (TSF) effect 67 8.1Theory................................ 67 8.1.1 Logarithmic thickness dependence -
Hadronic R Decays and QCD
FR0005562 LAL 99-78 December 1999 Hadronic r decays and QCD M. Davier Laboratoire de l'Accelerateur Lineaire IN2P3-CNRS et Universite de Paris-Sud, BP 34, F-91898 Orsay Cedex Invited talk given at the &h International Symposium on Heavy Flavour Physics University of Southampton, England, 25-29 July 1999 U.E.R Institut National de de Physique Nucleaire PUniversite Paris-Sud et de Physique des Particules 32/ 05 B.P. 34 ~ Bailment 200 - 91898 ORSAY CEDEX Gestion IH\S Doc. Enreg. I© .iU4/. N* TRN &&.O.O.OSS LAL 99-78 December 1999 Hadronic r decays and QCD Michel Davier Laboratoire de VAccel6rateur Lineaire IN2P3/CNRS et University de Paris-Sud 91898 Orsay, France E-mail: davierQlal.in2p3.fr ABSTRACT: Hadronic decays of the r lepton provide a clean source to study hadron dynamics in an energy regime dominated by resonances, with the interesting information captured in the spectral functions. Recent results on exclusive channels are reviewed. Inclusive spectral functions are the basis for QCD analyses, delivering an accurate determination of the strong coupling constant and quantitative information on nonperturbative contributions. Strange decays yield a determination of the strange quark mass. 1. Introduction Radiative corrections violate CVC, as contained in the SEW factor which is dominated by short- Hadrons produced in T decays are borne out of distance effects and thus expected to be essen- the charged weak current, i.e. out of the QCD tially final-state independent. vacuum. This property garantees that hadronic Hadronic r decays are then a clean probe of physics factorizes in these processes which are hadron dynamics in an interesting energy region then completely characterized for each decay chan- dominated by resonances. -
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..f.,5$1______ -~ survey -------) WHO WAS WHO IN KINETICS, REACTION ENGINEERING, AND CATALYSIS CAMI L. JACKSON AND JOSEPH H . HOLLES University of liyoming • Laramie, WY 82071 n the tradition of "Who was Who in Transport Phenom We have tried to include the names that are encountered ena" by Byron Bird in Chemical Engineering Education,CI J frequently in textbooks for both undergraduates and gradu Iwe have developed a similar set of microbiographies for ates (by noted authors such as Levenspiel, Hill, Fogler, and persons in the fields of kinetics, reaction engineering, and Froment and Bischoff). Again, we follow Bird's lead and do catalysis. As noted by Bird, an otherwise typical lecture not include these people simply for authoring books in these can be enlivened by presenting biographical information fields . We do, however, include-where appropriate- famous about the people whose names appear in famous equations, texts written by those scientists and engineers included for dimensionless groups, plots, approximations, and theories . other reasons. We have tried to focus on those persons who The wide variety of applications for this type of information contributed to the science of a field and not just contributed to has been demonstrated by using activity breaks to teach the a specific reaction or system (e.g., Haber and Bosch). While history of our professionl21 and as trading card rewards for contributions to specific reactions or systems are important, academic performance _l31 we elected not to include them in order to limit the scope of With the introduction and widespread acceptance ofWiki the project. Finally, we have tried to include interesting non pedia, basic biographical information on many of the early technical or non-professional information where possible to contributors to the profession of chemical engineering can be show the breadth of these individuals. -
Prix Andr Lagarrigue 2010
2010 André Lagarrigue Prize Under the sponsorship of the French Physical Society (SFP) and on the occasion of the 50th birthday of the Orsay Linear Accelerator Laboratory (LAL) in 2006, a prestigious Prize, awarded every second year, was created in honor of Professor André Lagarrigue. Director of LAL from 1969 until his untimely death in 1975. André Lagarrigue discovered, together with an European team, the weak interaction neutral currents in 1973, a crucial step in establishing the present theory of particle physics. The André Lagarrigue Prize rewards a senior physicist who has lead a large experimental project including conceptual design and realisation of a complex apparatus and has extracted the best of it with a strong team spirit and has carried out his work in a French laboratory or in close collaboration with French teams. This prize is co-financed by CEA, CERN, Ecole Polytechnique, IN2P3, LAL and the University Paris Sud 11. The international jury of the Andre Lagarrigue Prize1 met under the chairmanship of IN2P3 director Jacques Martino, and reviewed the nominees proposed by the French community of particles physics following a call for proposal sent to all French lab directors. The winner of the 2010 Andre Lagarrigue Prize is Michel Davier, Professor of Physics at the University Paris Sud 11 and a member of the French Academy of Science. Michel Davier's worldwide authority in the field of particle physics is undisputed and his prominent role is in every way worthy of that of André Lagarrigue. They share the same qualities of deep understanding of physics and of experimental devices of great complexity, of tenacity and pedagogy with the same passion for training young people. -
Mayda M. VELASCO Northwestern University, Dept. of Physics And
Mayda M. VELASCO Northwestern University, Dept. of Physics and Astronomy 2145 Sheridan Road, Evanston, IL 60208, USA Phone: Work: +1 847 467 7099 Cell: +1 847 571 3461 E-mail: [email protected] Last Updated: May 2016 Research Interest { High Energy Experimental Elementary Particle Physics: Work toward the understanding of fundamental interactions and its important role in: (a) solving the problem of CP violation in the Universe { Why is there more matter than anti- matter?; (b) explaning how mass is generated { Higgs mechanism and (c) finding the particle nature of Dark-Matter, if any... The required \new" physics phenomena is accessible at the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN). I am an active member of the Compact Muon Solenoid (CMS) collaboration already collect- ing data at the LHC, that led to the discovery of the Higgs boson or \God particle" in 2012. Education: • Ph.D. 1995: Northwestern University (NU) Experimental Particle Physics • 1995: Sicily, Italy ERICE: Spin Structure of Nucleon • 1994: Sorento, Italy CERN Summer School • B.S. 1988: University of Puerto Rico (UPR) Physics (Major) and Math (Minor) Rio Piedras Campus Fellowships and Honors: • 2015: NU, The Graduate School (TGS) Dean's Faculty Award for Diversity. • 2008-09: Paid leave of absence sponsored by US Department of Energy (DOE). • 2002-04: Sloan Research Fellow from Sloan Foundation. • 2002-03: Woodrow Wilson Fellow from Mellon Foundation. • 1999: CERN Achievement Award { Post-doctoral. • 1996-98: CERN Fellowship with Experimental Physics Division { Post-doctoral. • 1989-1995: Fermi National Accelerator Laboratory(FNAL)/URA Fellow { Doctoral. -
Sub Atomic Particles and Phy 009 Sub Atomic Particles and Developments in Cern Developments in Cern
1) Mahantesh L Chikkadesai 2) Ramakrishna R Pujari [email protected] [email protected] Mobile no: +919480780580 Mobile no: +917411812551 Phy 009 Sub atomic particles and Phy 009 Sub atomic particles and developments in cern developments in cern Electrical and Electronics Electrical and Electronics KLS’s Vishwanathrao deshpande rural KLS’s Vishwanathrao deshpande rural institute of technology institute of technology Haliyal, Uttar Kannada Haliyal, Uttar Kannada SUB ATOMIC PARTICLES AND DEVELOPMENTS IN CERN Abstract-This paper reviews past and present cosmic rays. Anderson discovered their existence; developments of sub atomic particles in CERN. It High-energy subato mic particles in the form gives the information of sub atomic particles and of cosmic rays continually rain down on the Earth’s deals with basic concepts of particle physics, atmosphere from outer space. classification and characteristics of them. Sub atomic More-unusual subatomic particles —such as particles also called elementary particle, any of various self-contained units of matter or energy that the positron, the antimatter counterpart of the are the fundamental constituents of all matter. All of electron—have been detected and characterized the known matter in the universe today is made up of in cosmic-ray interactions in the Earth’s elementary particles (quarks and leptons), held atmosphere. together by fundamental forces which are Quarks and electrons are some of the elementary represente d by the exchange of particles known as particles we study at CERN and in other gauge bosons. Standard model is the theory that laboratories. But physicists have found more of describes the role of these fundamental particles and these elementary particles in various experiments.