scholarly journals Towards the first measurement of matter-antimatter gravitational interaction

2018 ◽  
Vol 182 ◽  
pp. 02040
Author(s):  
C. Evans ◽  
S. Aghion ◽  
C. Amsler ◽  
G. Bonomi ◽  
R.S. Brusa ◽  
...  
Keyword(s):  
Stark Effect ◽  
Gravitational Interaction ◽  
Gravitational Acceleration ◽  
Exchange Reactions ◽  
Weak Equivalence Principle ◽  
Transmission Geometry ◽  
Position Sensitive ◽  
Pass Through ◽  
First Time ◽  
Electromagnetic Trap

The AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) is a CERN based experiment with the central aim to measure directly the gravitational acceleration of antihydrogen. Antihydrogen atoms will be produced via charge exchange reactions which will consist of Rydberg-excited positronium atoms sent to cooled antiprotons within an electromagnetic trap. The resulting Rydberg antihydrogen atoms will then be horizontally accelerated by an electric field gradient (Stark effect), they will then pass through a moiré deflectometer. The vertical deflection caused by the Earth's gravitational field will test for the first time the Weak Equivalence Principle for antimatter. Detection will be undertaken via a position sensitive detector. Around 103 antihydrogen atoms are needed for the gravitational measurement to be completed. The present status, current achievements and results will be presented, with special attention toward the laser excitation of positronium (Ps) to the n=3 state and the production of Ps atoms in the transmission geometry.

Antihydrogen physics: gravitation and spectroscopy in AEgISThis paper was presented at the International Conference on Precision Physics of Simple Atomic Systems, held at École de Physique, les Houches, France, 30 May – 4 June, 2010.

2011 ◽  
Vol 89 (1) ◽  
pp. 17-24 ◽  
Author(s):  
R. Ferragut ◽  
A. S. Belov ◽  
G. Bonomi ◽  
I. Boscolo ◽  
R. S. Brusa ◽  
...  
Keyword(s):  
Equivalence Principle ◽  
Stark Effect ◽  
Rydberg State ◽  
Free Fall ◽  
Second Phase ◽  
General Description ◽  
Exchange Reactions ◽  
Weak Equivalence Principle ◽  
Atomic Systems ◽  
Subsequent Measurement

AEgIS (Antimatter experiment: gravity, interferometry, spectroscopy) is an experiment approved by CERN with the goal of studying antihydrogen physics. In AEgIS, antihydrogen will be produced by charge exchange reactions of cold antiprotons with positronium atoms excited in a Rydberg state (n > 20). In the first phase of the experiment, controlled acceleration by an electric field gradient (Stark effect) and subsequent measurement of free fall in a Moiré deflectometer will allow a test of the weak equivalence principle. In a second phase, the antihydrogen will be slowed, confined, and laser-cooled to perform CPT studies and detailed spectroscopy. In the present work, after a general description of the experiment, the present status of advancement will be reviewed, with special attention to the production and excitation of positronium atoms.

scholarly journals Rigid ventilating video bronchoscope with forceps for bronchoscopic foreign body removal in children

2019 ◽  
Vol 5 (4) ◽  
pp. 1129
Author(s):  
Sagar Jawale ◽  
Parthapratim Gupta ◽  
Bharti Kulkarni
Keyword(s):  
Foreign Body ◽  
Gold Standard ◽  
Medical Literature ◽  
Rigid Bronchoscopy ◽  
Foreign Body Aspiration ◽  
Indian Children ◽  
Foreign Body Removal ◽  
Rigid Tube ◽  
Pass Through ◽  
First Time

<p>Bronchoscopic foreign body removal is a potentially dangerous and challenging procedure in pediatric surgery. bronchoscopy under general anaesthesia is the gold standard of diagnosis and management of foreign body aspiration. A large ventilating channel and better control over the tip of the instrument and cheaper instrument are the merits of rigid bronchoscopy over flexible one. Traditionally a rigid tube alone is used for this purpose which has extreme limitations of vision and it is risky. Foreign body aspiration typically occurs in 6 to 18 month age and the size of glottis is very small at this age. In Indian children who are small and malnourished the large assembly of sheath and telescope mounted forceps does not pass through the glottis. To overcome the limitations of the traditional equipment I designed my own bronchoscopy equipment by my 15 year of experience in bronchoscopy. This type of device is reported for the first time in medical literature and patent is filed for it at Mumbai office.</p><p> </p>

Micro Diffraction Imaging of Bulk Polycrystalline Materials

2006 ◽  
Vol 524-525 ◽  
pp. 273-278
Author(s):  
Thomas Wroblewski ◽  
A. Bjeoumikhov ◽  
Bernd Hasse
Keyword(s):  
High Spatial Resolution ◽  
Polycrystalline Materials ◽  
X Rays ◽  
X Ray Diffraction ◽  
Short Sample ◽  
X Ray ◽  
Detector Distance ◽  
Transmission Geometry ◽  
Diffraction Imaging ◽  
Position Sensitive

X-ray diffraction imaging applies an array of parallel capillaries in front of a position sensitive detector. Conventional micro channel plates of a few millimetre thickness have successfully been used as collimator arrays but require short sample to detector distances to achieve high spatial resolution. Furthermore, their limited absorption restricts their applications to low energy X-rays of around 10 keV. Progress in the fabrication of long polycapillaries allows an increase in the sample to detector distance without decreasing resolution and the use of high X-ray energies enables bulk investigations in transmission geometry.

scholarly journals Antimatter gravity and the Universe

2019 ◽  
Vol 35 (08) ◽  
pp. 2030001
Author(s):  
Dragan Slavkov Hajdukovic
Keyword(s):  
Gravitational Acceleration ◽  
Quantum Vacuum ◽  
Cpt Symmetry ◽  
Cyclic Universe ◽  
Gravitational Repulsion ◽  
Antimatter Gravity ◽  
Gravitational Dipoles ◽  
First Time ◽  
Theoretical Paradigms ◽  
The Universe

The aim of this brief review is twofold. First, we give an overview of the unprecedented experimental efforts to measure the gravitational acceleration of antimatter; with antihydrogen, in three competing experiments at CERN (AEGIS, ALPHA and GBAR), and with muonium and positronium in other laboratories in the world. Second, we present the 21st Century’s attempts to develop a new model of the Universe with the assumed gravitational repulsion between matter and antimatter; so far, three radically different and incompatible theoretical paradigms have been proposed. Two of these three models, Dirac–Milne Cosmology (that incorporates CPT violation) and the Lattice Universe (based on CPT symmetry), assume a symmetric Universe composed of equal amounts of matter and antimatter, with antimatter somehow “hidden” in cosmic voids; this hypothesis produced encouraging preliminary results. The heart of the third model is the hypothesis that quantum vacuum fluctuations are virtual gravitational dipoles; for the first time, this hypothesis makes possible and inevitable to include the quantum vacuum as a source of gravity. Standard Model matter is considered as the only content of the Universe, while phenomena usually attributed to dark matter and dark energy are explained as the local and global effects of the gravitational polarization of the quantum vacuum by the immersed baryonic matter. An additional feature is that we might live in a cyclic Universe alternatively dominated by matter and antimatter. In about three years, we will know if there is gravitational repulsion between matter and antimatter; a discovery that can forever change our understanding of the Universe.

scholarly journals The effect of hyperfine splitting on Stark broadening for three blue-green Cu i lines in laser-induced plasma

2019 ◽  
Vol 488 (4) ◽  
pp. 5594-5603 ◽  
Author(s):  
A M Popov ◽  
N I Sushkov ◽  
S M Zaytsev ◽  
T A Labutin
Keyword(s):  
Hyperfine Splitting ◽  
Stark Effect ◽  
Stellar Atmospheres ◽  
Spectral Lines ◽  
Stark Broadening ◽  
Laser Induced Plasma ◽  
Radiation Sources ◽  
And Shifts ◽  
First Time ◽  
Existing Data

ABSTRACT Stark effect is observed in many natural and artificial plasmas and is of great importance for diagnostic purposes. Since this effect alters profiles of spectral lines, it should be taken into account when assessing chemical composition of radiation sources, including stars. Copper is one of the elements which studies of stellar atmospheres deal with. To this end, UV and visible Cu lines are used. However, there is a lack of agreement between existing data on their Stark parameters. It is therefore of interest to obtain new experimental data on these lines and to compare them to previous results. In this work, we have estimated Stark widths and shifts for three blue-green lines at 5105.54, 5153.24, and 5218.20 Å (corresponding transitions are [3d104p] 2P° → [3d94s2] 2D and [3d104d] 2D → [3d104p] 2P°) observed in a ‘long-spark’ laser-induced plasma. For the first time, we have accurately estimated an impact of hyperfine splitting on the profile shapes of the studied lines taking also into account the isotope shifts. We have shown that both effects considerably influence shift and width of Cu i line at 5105.54 Å, and shifts of Cu i lines at 5153.24 and 5218.20 Å.

Constraints on gravitational properties of antimatter from cyclotron-frequency measurements

2014 ◽  
Vol 30 ◽  
pp. 1460260
Author(s):  
Michael H. Holzscheiter
Keyword(s):  
Gravitational Field ◽  
Gravitational Force ◽  
Normal Gravity ◽  
Free Fall ◽  
Gravitational Acceleration ◽  
Technical Problems ◽  
Weak Equivalence Principle ◽  
Normal Matter ◽  
Gravitational Experiment ◽  
Fall Experiment

A fundamental question in physics that has yet to be addressed experimentally is whether particles of antimatter, such as the antiproton or positron, obey the weak equivalence principle (WEP). Several theoretical arguments have been put forward arguing limits for possible violations of WEP. No direct `classical' gravitational experiment, the measurement of the free fall of an antiparticle, has been performed to date to determine if a particle of antimatter would experience a force in the gravitational potential of a normal matter body that is different from normal gravity. 30 years ago we proposed a free fall experiment using protons and antiprotons, modeled after the experiment to measure the gravitational acceleration of a free electron. At that time we gave consideration to yet another possible observation of gravitational differences between matter and antimatter based on the gravitational red shift of clocks. I will recall the original arguments and make a number of comments pertaining to the technical problems and other issues that prevented the execution of the antiproton free fall measurement. Note that a different gravitational force on antimatter in the gravitational field of matter would not constitute a violation of CPT, as this is only concerned with the gravitational acceleration of antimatter in the gravitational field of an antimatter body.

Mechanisms and models for homogeneous copper mediated ligand exchange reactions of the type: CuNu + ArX → ArNu + CuX

1985 ◽  
Vol 63 (1) ◽  
pp. 111-120 ◽  
Author(s):  
Christiane Couture ◽  
Anthony James Paine
Keyword(s):  
Molecular Design ◽  
Nucleophilic Aromatic Substitution ◽  
Common Mechanism ◽  
Aromatic Substitution ◽  
Exchange Reactions ◽  
Design And Synthesis ◽  
Alkyl Groups ◽  
Leaving Group ◽  
First Time ◽  
Redox Equilibria

The title reactions are an important class of copper mediated nucleophilic aromatic substitution processes, which constitute a useful tool in the molecular design and synthesis of small molecules. We report the results of extensive investigation of these processes, primarily focussing on cyanodeiodination (ArI + CuCN → CuI + ArCN). Among the interesting features of these processes are: (a) an unusual rate equation involving autocatalysis by CuI product; (b) retardation by both excess nucleophile (as KCN) and excess leaving group (as KI), which compete with ArX to complex with CuNu; (c) only cuprous nucleophiles are active (ligand exchanged products from cupric salts arise from prior redox equilibria which form CuNu); (d) the halogen effect is large (kI ~ 40–100 kBr ~ 300–5000kCl) but the Hammett ρ value is zero; (e) ortho-alkyl groups do not hinder the reaction (and actually cause mild acceleration by relief of steric strain). Finally, the introduction of an ortho-COO− group accelerates the reaction by a factor of 104–105, but the general features of the accelerated reactions are also the same, again indicating a common mechanism, with entropic acceleration by ortho-carboxylate. Both kinetic and thermodynamic factors were considered in detail, the latter apparently for the first time. Applications to practical syntheses are considered, and novel mechanistic models for these interesting processes are discussed.

ELECTRON MOMENTUM SPECTROSCOPY OF SURFACES

1999 ◽  
Vol 06 (05) ◽  
pp. 579-584 ◽  
Author(s):  
S. TIXIER ◽  
Y. ZHENG ◽  
T. TIEDJE ◽  
G. COOPER ◽  
C. E. BRION
Keyword(s):  
Gas Phase ◽  
Momentum Distribution ◽  
Electron Momentum ◽  
Electron Momentum Distribution ◽  
Electrostatic Analyzer ◽  
Transmission Geometry ◽  
Electron Momentum Spectroscopy ◽  
Reflection Geometry ◽  
Position Sensitive ◽  
Position Sensitive Detectors

Electron momentum spectroscopy [binary (e,2e) spectroscopy] using transmission geometry is a unique experimental tool for imaging the electron momentum distribution in gas phase samples as well as in thin films. In a solid, the electron momentum distribution is related to the band structure. Development of the (e,2e) technique using a more versatile reflection geometry is attractive since a much wider range of surfaces could be studied. The design of a new reflection (e,2e) spectrometer is presented. It is based on a two-step scattering model in which an incident electron successively reflects and ejects a valence electron from the surface. The scattered and ejected electrons are detected in coincidence and their energies and momentum vectors are simultaneously determined using a high throughput 90° truncated spherical electrostatic analyzer and position-sensitive detectors.

Mikrowellenspektrum, Struktur und l-Typ-Dublett-Aufspaltung der HCNO (Knallsäure)

1967 ◽  
Vol 22 (11) ◽  
pp. 1724-1737 ◽  
Author(s):  
Manfred Winnewisser ◽  
Hans Karl Bodenseh
Keyword(s):  
Ground State ◽  
Stark Effect ◽  
Coupling Constants ◽  
Vibrational Modes ◽  
Quadrupole Coupling ◽  
Bending Modes ◽  
First Time ◽  
O 11 ◽  
O 10 ◽  
Marked Dependence

The microwave spectra of unstable, gaseous fulminic acid H12C14N16O and five of its isotopically substituted species have been studied in the frequency range from 10 to 46 GHz. The spectrum of molecules in the ground vibrational state established the linearity of the chain HCNO. The following rotational constants B0 for the ground state were obtained:B0 (H12C14N16O) = 11 469.04 MHz, B0 (H12C14N17O) = 11 151.69 MHz,B0 (D12C14N16O) = 10 292.51 MHz, B0 (H12C14N18O) = 10 865.34 MHz,B0 (H13C14N16O) = 11 091.57 MHz, B0 (D13C14N16O) = 10 011.18 MHz.From these a combined r8- and r0-structure has been evaluated: r(C—H) = (1.027±0.001) A, r(C—N) = (1.161 ± 0.015) A, r(N—O) = (1.207±0.015) A.The rather large uncertainties in the C—N- and N—O-distances are due to the proximity of the N-atom to the center of gravity.It appears to be the first time that, in the same molecule, two different ι-type doublets (Δl=0, AJ= + 1) and their corresponding series of /-type doubling transitions (Al =2, ΔJ = 0), arising from the two degenerate bending modes (υ4=1 and v5=1), have been observed.The analysis of the two ι-type doubling series revealed a marked dependence of the /-type doubling constants q4 and q5 on higher powers of the angular momentum J. This J-dependence was found to be substantially different for the two vibrational modes.The doubling constants given in MHz areq4=23.6722 - (0.6139·10-3) J(J+1) + (0.1417·10-6) [J(J+1)]2-(0199·10-10) [J(J+1)]3,q5=34.6391 - (0.1623·10-3) J(J+1) + (1.00·10-9) [J(J+1)]2.The molecular dipole moment was determined from Stark-effect measurements on the J=0 → 1 transition in the ground state and found to be (3.06 ± 0.15) Debye. The nuclear quadrupole coupling constants for the 14N- and 170-nuclei can be given ase q Q (17O) = — (12.31 ± 0.12) MHz and | e q Q (14N) | ≦ 0.3 MHz.

scholarly journals Invasive Pest and Disease Pathogen as Sneakers in Railways for Their Spread in Different Ecological Region: A New Report

2021 ◽  
Vol 3 (1) ◽  
pp. 124-127
Author(s):  
Suresh Borkar
Keyword(s):  
Insect Pest ◽  
Uttar Pradesh ◽  
Early Morning ◽  
Invasive Pest ◽  
Positive Phototaxis ◽  
Crop Pest ◽  
Ecological Region ◽  
Pass Through ◽  
Banana Leaves ◽  
First Time

A new pathway of travels by invasive pest and disease pathogen through railways, as sneakers, were noticed for the first time. The Indian railways passing through the soybean fields infested with Spodoptera litura, after evening attracted the moth of Spodoptera by the illuminating lights in the railways compartment and the moth enters into the compartment through open compartment windows. These moths remain in the railway compartment until the dawn and get out of the compartment as the early morning sun light enters into the compartments and are thus the sneakers crop pest in railways due to their unnoticed travels/transport. Such sneakers crop pest travels up to a distance of 600 km during the period of night from one ecological region to another ecological region having the same crop to infest or the alternative host crop of the pest to cause the fresh infestation. This phenomenon of pest travel was observed in the region of Lalitpur in Uttar Pradesh, India, having soybean infestation. This is a quick travel by the pest into different areas, unseen and unreported earlier and may occur in any part of the world where the railways pass through the infested crop areas and attract the positive phototaxis pest and transport them, as sneakers, in to another ecological region. In another instance, the Sigatoka disease pathogen of banana was also noticed to travels from one ecological region to another ecological region through the railways, as sneakers without notice. This phenomenon of disease pathogen’s travels was noticed in Jalgaon region from where the banana produce is transported to different parts of India. In the trading and transport of banana through railways, the loaders use the banana leaves infected with the sigatoka pathogen as a packaging material for banana bunches while loading the banana produce in the railway wagons for their transportation. Thus, the sigatoka pathogen travels up to a distance of 1200 km/day along with the banana produce through the railways. The sigatoka infected leaves, with the unloading of banana produce also sneaks into the new ecological region and spread to infect the banana crop available in the region. Thus, the positive phototaxis insect pest are the sneakers in the railways for their travels while diseases pathogens with healthy crop produce travels and embarks to sneaks into a new ecological region and thus the railways transport system unintentionally transport the crop pest and disease pathogen from one ecological region to another. The knowledge of this new travel pathway will be useful in finalizing the strategies of plant quarantine and management of invasive pest and disease pathogens.

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