Experiment 7: Spectrum of the Hydrogen Atom
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Stability of Narrow-Band Filter Radiometers in the Solar-Reflective Range
Stability of Narrow-Band Filter Radiometers in the Solar-Reflective Range D. E. Flittner and P. N. Slater Optical Sciences Center, University of Arizona, Tucson, AZ 85721 ABSTRACT:We show that the calibration, with respect to a continuous-spech.umsource, and the stability of radiometers using filters of about 10 nm full width, half maximum (FWHM) in the wavelength interval 0.4 to 1.0 pm, can change by several percent if the filters change in position by only a few nanometres. The cause is the shifts of the passbands of the filters into or out of Fraunhofer lines in the solar spectrum or water vapor or oxygen absorption bands in the Earth's atmosphere. These shifts can be due to ageing accompanied by the absorption of water vapor into the filter or temperature changes for field radiometers, or to outgassing and possibly high energy solar irradiation for space instru- ments such as the MODerate resolution Imaging Spectrometer - Nadir (MODIS-N) proposed for the Earth Observing System. INTRODUCTION sun, but can lead to errors in moderate to high spectral reso- lution measurements of the Earth-atmosphere system if their T IS WELL KNOWN that satellite multispectral sensor data in Ithe visible and near infrared are acquired with spectral band- effect is not taken into account. The concern is that the narrow- widths from about 40 nm (System Probatoire &Observation de band filters in a radiometer may shift, causing them to move la Terre (SPOT) band 2) and 70 nm (Thematic Mapper (TM)band into or out of a region containing a Fraunhofer line, thereby 3) to about 200 and 400 nm (Multispectral Scanner System (MSS) causing a noticeable change in the radiometer output. -
Fraunhofer Lidar Prototype in the Green Spectral Region for Atmospheric Boundary Layer Observations
Remote Sens. 2013, 5, 6079-6095; doi:10.3390/rs5116079 OPEN ACCESS Remote Sensing ISSN 2072-4292 www.mdpi.com/journal/remotesensing Article Fraunhofer Lidar Prototype in the Green Spectral Region for Atmospheric Boundary Layer Observations Songhua Wu *, Xiaoquan Song and Bingyi Liu Ocean Remote Sensing Institute, Ocean University of China, 238 Songling Road, Qingdao 266100, China; E-Mails: [email protected] (X.S.); [email protected] (B.L.) * Author to whom correspondence should be addressed; E-Mail: [email protected]; Tel.: +86-532-6678-2573. Received: 8 October 2013; in revised form: 27 October 2013 / Accepted: 13 November 2013 / Published: 18 November 2013 Abstract: A lidar detects atmospheric parameters by transmitting laser pulse to the atmosphere and receiving the backscattering signals from molecules and aerosol particles. Because of the small backscattering cross section, a lidar usually uses the high sensitive photomultiplier and avalanche photodiode as detector and uses photon counting technology for collection of weak backscatter signals. Photon Counting enables the capturing of extremely weak lidar return from long distance, throughout dark background, by a long time accumulation. Because of the strong solar background, the signal-to-noise ratio of lidar during daytime could be greatly restricted, especially for the lidar operating at visible wavelengths where solar background is prominent. Narrow band-pass filters must therefore be installed in order to isolate solar background noise at wavelengths close to that of the lidar receiving channel, whereas the background light in superposition with signal spectrum, limits an effective margin for signal-to-noise ratio (SNR) improvement. This work describes a lidar prototype operating at the Fraunhofer lines, the invisible band of solar spectrum, to achieve photon counting under intense solar background. -
The Solar Spectrum: an Atmospheric Remote Sensing Perspecnve
The Solar Spectrum: an Atmospheric Remote Sensing Perspec7ve Geoffrey Toon Jet Propulsion Laboratory, California Ins7tute of Technology Noble Seminar, University of Toronto, Oct 21, 2013 Copyright 2013 California Instute of Technology. Government sponsorship acknowledged. BacKground Astronomers hate the Earth’s atmosphere – it impedes their view of the stars and planets. Forces them to make correc7ons for its opacity. Atmospheric scien7sts hate the sun – the complexity of its spectrum: • Fraunhofer absorp7on lines • Doppler shis • Spaal Non-uniformi7es (sunspots, limb darKening) • Temporal variaons (transits, solar cycle, rotaon, 5-minute oscillaon) all of which complicate remote sensing of the Earth using sunlight. In order to more accurately quan5fy the composi5on of the Earth’s atmosphere, it is necessary to beFer understand the solar spectrum. Mo7vaon Solar radiaon is commonly used for remote sensing of the Earth: • the atmosphere • the surface Both direct and reflected sunlight are used: • Direct: MkIV, ATMOS, ACE, SAGE, POAM, NDACC, TCCON, etc. • Reflected: OCO, GOSAT, SCIAMACHY, TOMS, etc. Sunlight provides a bright, stable, and spectrally con7nuous source. As accuracy requirements on atmospheric composi5on measurements grows more stringent (e.g. TCCON), beFer representa5ons of the solar spectrum are needed. Historical Context Un7l 1500 (Copernicus), it was assumed that the Sun orbited the Earth. Un7l 1850 sun was assumed 6000 years old, based on the Old Testament. Sunspots were considered openings in the luminous exterior of the sun, through which the sun’s solid interior could be seen. 1814: Fraunhofer discovers absorp7on lines in visible solar spectrum 1854: von Helmholtz calculated sun must be ~20MY old based on heang by gravitaonal contrac7on. -
Spectroscopy and the Stars
SPECTROSCOPY AND THE STARS K H h g G d F b E D C B 400 nm 500 nm 600 nm 700 nm by DR. STEPHEN THOMPSON MR. JOE STALEY The contents of this module were developed under grant award # P116B-001338 from the Fund for the Improve- ment of Postsecondary Education (FIPSE), United States Department of Education. However, those contents do not necessarily represent the policy of FIPSE and the Department of Education, and you should not assume endorsement by the Federal government. SPECTROSCOPY AND THE STARS CONTENTS 2 Electromagnetic Ruler: The ER Ruler 3 The Rydberg Equation 4 Absorption Spectrum 5 Fraunhofer Lines In The Solar Spectrum 6 Dwarf Star Spectra 7 Stellar Spectra 8 Wien’s Displacement Law 8 Cosmic Background Radiation 9 Doppler Effect 10 Spectral Line profi les 11 Red Shifts 12 Red Shift 13 Hertzsprung-Russell Diagram 14 Parallax 15 Ladder of Distances 1 SPECTROSCOPY AND THE STARS ELECTROMAGNETIC RADIATION RULER: THE ER RULER Energy Level Transition Energy Wavelength RF = Radio frequency radiation µW = Microwave radiation nm Joules IR = Infrared radiation 10-27 VIS = Visible light radiation 2 8 UV = Ultraviolet radiation 4 6 6 RF 4 X = X-ray radiation Nuclear and electron spin 26 10- 2 γ = gamma ray radiation 1010 25 10- 109 10-24 108 µW 10-23 Molecular rotations 107 10-22 106 10-21 105 Molecular vibrations IR 10-20 104 SPACE INFRARED TELESCOPE FACILITY 10-19 103 VIS HUBBLE SPACE Valence electrons 10-18 TELESCOPE 102 Middle-shell electrons 10-17 UV 10 10-16 CHANDRA X-RAY 1 OBSERVATORY Inner-shell electrons 10-15 X 10-1 10-14 10-2 10-13 10-3 Nuclear 10-12 γ 10-4 COMPTON GAMMA RAY OBSERVATORY 10-11 10-5 6 4 10-10 2 2 -6 4 10 6 8 2 SPECTROSCOPY AND THE STARS THE RYDBERG EQUATION The wavelengths of one electron atomic emission spectra can be calculated from the Use the Rydberg equation to fi nd the wavelength ot Rydberg equation: the transition from n = 4 to n = 3 for singly ionized helium. -
Resonance Raman Scattering of Light from a Diatomic Molecule
University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Electrical & Computer Engineering, Department P. F. (Paul Frazer) Williams Publications of May 1976 Resonance Raman scattering of light from a diatomic molecule D. L. Rousseau Bell Laboratories, Murray Hill, New Jersey P. F. Williams University of Nebraska - Lincoln, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/elecengwilliams Part of the Electrical and Computer Engineering Commons Rousseau, D. L. and Williams, P. F., "Resonance Raman scattering of light from a diatomic molecule" (1976). P. F. (Paul Frazer) Williams Publications. 24. https://digitalcommons.unl.edu/elecengwilliams/24 This Article is brought to you for free and open access by the Electrical & Computer Engineering, Department of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in P. F. (Paul Frazer) Williams Publications by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Resonance Raman scattering of light from a diatomic molecule D. L. Rousseau Bell Laboratories. Murray Hill, New Jersey 07974 P. F. Williams Bell Laboratories, Murray Hill, New Jersey 07974 and Department of Physics, University of Puerto Rico, Rio Piedras, Puerto Rico 00931 (Received 13 October 1975) Resonance Raman scattering from a homonuclear diatomic molecule is considered in detail. For convenience, the scattering may be classified into three excitation frequency regions-off-resonance Raman scattering for inciderit energies well away from resonance with any allowed transitions, discrete resonance Raman scattering for excitation near or in resonance with discrete transitions, and continuum resonance Raman scattering for excitation resonant with continuum transitions, e.g., excitation above a dissociation limit or into a repulsive electronic state. -
The Demographics of Massive Black Holes
The fifth element: astronomical evidence for black holes, dark matter, and dark energy A brief history of astrophysics • Greek philosophy contained five “classical” elements: °earth terrestrial; subject to °air change °fire °water °ether heavenly; unchangeable • in Greek astronomy, the universe was geocentric and contained eight spheres, seven holding the known planets and the eighth the stars A brief history of astrophysics • Nicolaus Copernicus (1473 – 1543) • argued that the Sun, not the Earth, was the center of the solar system • the Copernican Principle: We are not located at a special place in the Universe, or at a special time in the history of the Universe Greeks Copernicus A brief history of astrophysics • Isaac Newton (1642-1747) • the law of gravity that makes apples fall to Earth also governs the motions of the Moon and planets (the law of universal gravitation) ° thus the square of the speed of a planet in its orbit varies inversely with its radius ⇒ the laws of physics that can be investigated in the lab also govern the behavior of stars and planets (relative to Earth) A brief history of astrophysics • Joseph von Fraunhofer (1787-1826) • discovered narrow dark features in the spectrum of the Sun • realized these arise in the Sun, not the Earth’s atmosphere • saw some of the same lines in the spectrum of a flame in his lab • each chemical element is associated with a set of spectral lines, and the dark lines in the solar spectrum were caused by absorption by those elements in the upper layers of the sun ⇒ the Sun is made of the same elements as the Earth A brief history of astrophysics ⇒ the Sun is made of the same elements as the Earth • in 1868 Fraunhofer lines not associated with any known element were found: “a very decided bright line...but hitherto not identified with any terrestrial flame. -
Fraunhofer Lines and the Composition of the Sun 1 Summary 2 Papers and Datasets 3 Scientific Background
Fraunhofer lines and the composition of the Sun 1 Summary The purpose of this lab is for you to examine the spectrum of the Sun, to learn about the composition of the Sun (it’s not just hydrogen and helium!), and to understand some basic concepts of spectroscopy. 2 Papers and datasets These documents are all available on the course web page. • Low resolution spectrum of the Sun (from the National Solar Observatory) • Absorption lines of various elements (from laserstars.org and NASA’s Goddard Space Flight Center) • Table of abundances in the Sun 3 Scientific background 3.1 Spectroscopy At its most basic level, spectroscopy is simply splitting light up into different wavelengths. The classic example is a prism: white light goes in, and a rainbow comes out. Spectroscopy for physics and astronomy usually drops the output onto some kind of detector that records the flux at different wavelengths as a “stripe” across the detector. In other words, the output is a data table that lists the measured flux as a function of pixel number. An critical aspect of spectroscopy is wavelength calibration: what wavelength corresponds to which pixel number? Note that that relationship does not have to be — and is often not — linear. That is, the mapping of wavelength to pixel is not a linear relationship, but something more complicated. 3.2 The Sun The Sun is mostly hydrogen and after that mostly helium. You have learned about the fusion processes in the Sun and in other stars that gradually convert hydrogen to helium and then, for some stars, onward to carbon, nitrogen, and oxygen (CNO cycle), and further upward through the periodic table to iron. -
Raman Spectroscopy for In-Line Water Quality Monitoring — Instrumentation and Potential
Sensors 2014, 14, 17275-17303; doi:10.3390/s140917275 OPEN ACCESS sensors ISSN 1424-8220 www.mdpi.com/journal/sensors Review Raman Spectroscopy for In-Line Water Quality Monitoring — Instrumentation and Potential Zhiyun Li 1, M. Jamal Deen 1,2,4,*, Shiva Kumar 2 and P. Ravi Selvaganapathy 1,3 1 School of Biomedical Engineering, McMaster University, Hamilton, ON L8S 4K1, Canada; E-Mails: [email protected] (Z.L.); [email protected] (P.R.S.) 2 Electrical and Computer Engineering, McMaster University, Hamilton, ON L8S 4K1 Canada; E-Mail: [email protected] 3 Mechanical Engineering, McMaster University, Hamilton, ON L8S 4K1, Canada 4 Electronic and Computer Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China * Author to whom correspondence should be addressed; E-Mail: [email protected] or [email protected]; Tel.: +1-905-525-9140 (ext. 27137); Fax: +1-905-521-2922. Received: 1 July 2014; in revised form: 7 September 2014 / Accepted: 9 September 2014 / Published: 16 September 2014 Abstract: Worldwide, the access to safe drinking water is a huge problem. In fact, the number of persons without safe drinking water is increasing, even though it is an essential ingredient for human health and development. The enormity of the problem also makes it a critical environmental and public health issue. Therefore, there is a critical need for easy-to-use, compact and sensitive techniques for water quality monitoring. Raman spectroscopy has been a very powerful technique to characterize chemical composition and has been applied to many areas, including chemistry, food, material science or pharmaceuticals. -
Basics of Plasma Spectroscopy
Home Search Collections Journals About Contact us My IOPscience Basics of plasma spectroscopy This content has been downloaded from IOPscience. Please scroll down to see the full text. 2006 Plasma Sources Sci. Technol. 15 S137 (http://iopscience.iop.org/0963-0252/15/4/S01) View the table of contents for this issue, or go to the journal homepage for more Download details: IP Address: 198.35.1.48 This content was downloaded on 20/06/2014 at 16:07 Please note that terms and conditions apply. INSTITUTE OF PHYSICS PUBLISHING PLASMA SOURCES SCIENCE AND TECHNOLOGY Plasma Sources Sci. Technol. 15 (2006) S137–S147 doi:10.1088/0963-0252/15/4/S01 Basics of plasma spectroscopy U Fantz Max-Planck-Institut fur¨ Plasmaphysik, EURATOM Association Boltzmannstr. 2, D-85748 Garching, Germany E-mail: [email protected] Received 11 November 2005, in final form 23 March 2006 Published 6 October 2006 Online at stacks.iop.org/PSST/15/S137 Abstract These lecture notes are intended to give an introductory course on plasma spectroscopy. Focusing on emission spectroscopy, the underlying principles of atomic and molecular spectroscopy in low temperature plasmas are explained. This includes choice of the proper equipment and the calibration procedure. Based on population models, the evaluation of spectra and their information content is described. Several common diagnostic methods are presented, ready for direct application by the reader, to obtain a multitude of plasma parameters by plasma spectroscopy. 1. Introduction spectroscopy for purposes of chemical analysis are described in [11–14]. Plasma spectroscopy is one of the most established and oldest diagnostic tools in astrophysics and plasma physics 2. -
Fluorescent, Prussian Blue-Based Biocompatible Nanoparticle System for Multimodal Imaging Contrast
Supplementary Materials Fluorescent, Prussian Blue-Based Biocompatible Nanoparticle System for Multimodal Imaging Contrast László Forgách 1,*, Nikolett Hegedűs 1, Ildikó Horváth 1, Bálint Kiss 1, Noémi Kovács 1, Zoltán Varga 1,2, Géza Jakab 3, Tibor Kovács 4, Parasuraman Padmanabhan 5, Krisztián Szigeti 1,*,† and Domokos Máthé 1,6,7,*,† 1 Department of Biophysics and Radiation Biology, Semmelweis University, 1085 Budapest, Hungary; [email protected] (N.H.); [email protected] (I.H.); [email protected] (B.K.); [email protected] (N.K.); [email protected] (Z.V.) 2 Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, 1117 Budapest, Hungary; [email protected] (Z.V.) 3 Department of Pharmaceutics, Semmelweis University, 1085 Budapest, Hungary; [email protected] 4 University of Pannonia, Institute of Radiochemistry and Radioecology, 8200 Veszprém, Hungary; [email protected] 5 Lee Kong Chian School of Medicine, Nanyang Technological University, 636921 Singapore, Singapore; [email protected] 6 In Vivo Imaging Advanced Core Facility, Hungarian Centre of Excellence for Molecular Medicine, 6723 Szeged, Hungary 7 CROmed Translational Research Centers, 1047 Budapest, Hungary * Correspondence: [email protected] (L.F.); [email protected] univ.hu (K.S.); [email protected] (D.M.); Tel.: +36-1-459-1500/60164 (L.F.); +36-1- 459-1500/60210 (D.M.) † These authors contributed equally to this work. Native, citrate-coated PBNPs The mean hydrodynamic diameter (intensity-based harmonic means or z-average) of citrate- coated PBNPs was 29.30 ± 2.08 (average ± SD, 푛 = 8), as determined by DLS. -
Ice Features in the Mid-IR Spectra of Galactic Nuclei?
A&A 385, 1022–1041 (2002) Astronomy DOI: 10.1051/0004-6361:20020147 & c ESO 2002 Astrophysics Ice features in the mid-IR spectra of galactic nuclei? H. W. W. Spoon1,2,J.V.Keane2,A.G.G.M.Tielens2,3,D.Lutz4,A.F.M.Moorwood1, and O. Laurent4 1 European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching, Germany e-mail: [email protected]; [email protected] 2 Kapteyn Institute, PO Box 800, 9700 AV Groningen, The Netherlands e-mail: [email protected]; [email protected] 3 SRON, PO Box 800, 9700 AV Groningen, The Netherlands 4 Max-Planck-Institut f¨ur Extraterrestrische Physik (MPE), Postfach 1312, 85741 Garching, Germany e-mail: [email protected] Received 28 November 2001 / Accepted 24 January 2002 Abstract. Mid infrared spectra provide a powerful probe of the conditions in dusty galactic nuclei. They variously contain emission features associated with star forming regions and absorptions by circumnuclear silicate dust plus ices in cold molecular cloud material. Here we report the detection of 6–8 µm water ice absorption in 18 galaxies observed by ISO. While the mid-IR spectra of some of these galaxies show a strong resemblance to the heavily absorbed spectrum of NGC 4418, other galaxies in this sample also show weak to strong PAH emission. The 18 ice galaxies are part of a sample of 103 galaxies with good S/N mid-IR ISO spectra. Based on our sample we find that ice is present in most of the ULIRGs, whereas it is weak or absent in the large majority of Seyferts and starburst galaxies. -
Supporting Information Kerr Gated Raman Spectroscopy of Lipf6 Salt
Electronic Supplementary Material (ESI) for Physical Chemistry Chemical Physics. This journal is © the Owner Societies 2019 Supporting Information Kerr gated Raman spectroscopy of LiPF6 salt and LiPF6-based organic carbonate electrolyte for Li-ion batteries Laura Cabo-Fernandez,[a] Alex R. Neale,[a] Filipe Braga,[a] Igor V. Sazanovich,[b] Robert Kostecki,[c] Laurence J. Hardwick*[a] [a] Stephenson Institute for Renewable Energy, Department of Chemistry, University of Liverpool, Peach Street, Liverpool, L69 7ZF (United Kingdom). [b] Central Laser Facility, Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Harwell Campus, Didcot, Oxfordshire, OX11 0QX (United Kingdom). [c] Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States). * [email protected] S1 Principles of Raman spectroscopy When a sample is lightened by a laser, the molecule interacts with the incident photon through the virtual energy level and then another photon is scattered; therefore, scattering processes can be looked at as the absorption of one photon and the instantaneous emission of another photon. The process is elastic if the scattered photon has the same energy as the incident one (Es=Ei), in which case it is known as Rayleigh scattering, or if both photons have different energy (Es≠Ei) it is an inelastic process. Raman spectroscopy is based on these inelastic phenomena and it could be a Stokes scattering if the scattered photon has less energy than the incident one (Es< Ei) or if it has more energy (Es>Ei) an anti-Stokes scattering, as seen in Figure 1 (a). Fluorescence lifetime and quantum yields1 Fluorescence quantum yield (Q) defined as the ratio of photons emitted to the number of photons absorbed1 could be equal to 1, whereas the yield of Raman inelastic scattering can be several orders of magnitude lower.