Charge diffusion in the field-free region of charge-coupled devices

The goal of the ASACUSA-CUSP collaboration at the Antiproton Decelerator of CERN is to measure the ground-state hyperfine splitting of antihydrogen using an atomic spectroscopy beamline. A milestone was achieved in 2012 through the detection of 80 antihydrogen atoms 2.7 m away from their production region. This was the first observation of ‘cold’ antihydrogen in a magnetic field free region. In parallel to the progress on the antihydrogen production, the spectroscopy beamline was tested with a source of hydrogen. This led to a measurement at a relative precision of 2.7×10 −9 which constitutes the most precise measurement of the hydrogen hyperfine splitting in a beam. Further measurements with an upgraded hydrogen apparatus are motivated by CPT and Lorentz violation tests in the framework of the Standard Model Extension. Unlike for hydrogen, the antihydrogen experiment is complicated by the difficulty of synthesizing enough cold antiatoms in the ground state. The first antihydrogen quantum states scan at the entrance of the spectroscopy apparatus was realized in 2016 and is presented here. The prospects for a ppm measurement are also discussed. This article is part of the Theo Murphy meeting issue ‘Antiproton physics in the ELENA era’.

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Field-Free Region (FFR)

IUPAC Standards Online ◽

10.1515/iupac.85.0457 ◽

2016 ◽

Author(s):

Kermit K. Murray ◽

Robert K. Boyd ◽

Marcos N. Eberlin ◽

G. John Langley ◽

Liang Li ◽

...

Keyword(s):

Free Region ◽

Field Free Region

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Synthesis and properties of an electron-ion plasma

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1961.0204 ◽

1961 ◽

Vol 264 (1318) ◽

pp. 355-366

Keyword(s):

Plasma Frequency ◽

Electron Velocity ◽

Signal Frequency ◽

Electric Signal ◽

Lithium Aluminium ◽

Ion Plasma ◽

Free Region ◽

Field Free Region ◽

Field Lines ◽

Singly Charged

It is shown that a low-density neutral plasma in a steady state, consisting of electrons and ions only, can be obtained by injecting opposing beams of charges into a field-free region. With the aid of electrostatic probes the electric neutrality of such a synthetic plasma can be controlled. Experiments were carried out with a plasma consisting of singly charged lithium ions of energy up to 300 eV drawn from a lithium-aluminium silicate emitter and electrons of energy 12 to 24 eV drawn from a dispenser cathode. The residual gas pressure was kept so low that collision with atoms did not contribute to the effects measured. A continuous electric signal of frequency 2 to 30 Mc/s was transmitted through the plasma. Whereas in a gaseous plasma a resonance peak at the plasma frequency was found by varying either the signal frequency or the discharge current (and thus the plasma frequency), a resonance absorption was recorded in an electron-ion plasma. This suggests that for frequencies lower than that corresponding to an individual electron crossing the region of influence of the signal the phase of the electron oscillation always tends to reduce the local field. As the electron velocity was raised the magnitude of absorption was shown to grow. The transmission in the electron-ion plasma was also studied with a magnetic field parallel to the direction of the beams which caused the electrons to circulate about the field lines. By varying the field strength the absorption was found to reach a maximum when the electron cyclotron frequency equals the plasma frequency. The width of the absorption curves for the electron-ion plasma was greater than that with an electron beam only. The interaction between ions and electrons has been demonstrated by measuring the electric noise produced by the plasma. For electron energies between 10 and 70 eV the increase in noise corresponds to a change of the electron temperature by 400 to 500 °K or to an average scattering angle of 1 to 3°.

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Positron extraction to an electromagnetic field free region

Journal of Physics B Atomic Molecular and Optical Physics ◽

10.1088/0953-4075/49/1/014001 ◽

2015 ◽

Vol 49 (1) ◽

pp. 014001 ◽

Cited By ~ 5

Author(s):

D A Cooke ◽

G Barandun ◽

S Vergani ◽

B Brown ◽

A Rubbia ◽

...

Keyword(s):

Electromagnetic Field ◽

Free Region ◽

Field Free Region

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Behaviorof Ion Beams For Triplet Quadrupole Lenses

Al-Mustansiriyah Journal of Science ◽

10.23851/mjs.v27i5.174 ◽

2017 ◽

Vol 27 (5) ◽

pp. 95

Author(s):

Hiyam Chasib Majed ◽

Ameera Jawad Kadhem ◽

Esraa Akram Abass ◽

Taghreed Khalid Hameed

Keyword(s):

Ion Beam ◽

Free Field ◽

Charged Particles ◽

Vertical Plane ◽

System Matrix ◽

Free Region ◽

Field Free Region ◽

Region Length ◽

Quadrupole Lenses ◽

Focusing Properties

This research includes a study to understand the behavior of charged particles beam through consideration of systems of quadrupole triplet reaching to the optimum design of beam transport through a system of triplet quadrupole triplet lenses. In this work, tracing the path of charged particles beam has been within the free field space and quadrupole electrostatic lens system which include the triplet quadrupolelens by using matrices to described particle trajectories throughout the system. Matrix representation deals with ion beam as bunched and representing phase ellipse for both horizontal and vertical planes. The present work investigated the effect of the main parameters of triplet quadruple such as length of quadrupole, the distance between the lenses, voltage applying on lenses,second field free region length. Matlab program built to study these parameters, the results indicated that good focusing properties for both horizontal and vertical plane.

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Design and Control of Field-Free Region Using Two Permanent Magnets for Selective Magnetic Hyperthermia

IEEE Access ◽

10.1109/access.2019.2926793 ◽

2019 ◽

Vol 7 ◽

pp. 96094-96104 ◽

Cited By ~ 1

Author(s):

Armando Ramos Sebastian ◽

Se Hwan Ryu ◽

Haye Min Ko ◽

Sung Hoon Kim

Keyword(s):

Permanent Magnets ◽

Magnetic Hyperthermia ◽

Free Region ◽

Field Free Region ◽

And Control

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Coherent excitation of then=3 level of hydrogen in a field free region

Zeitschrift für Physik A Atoms and Nuclei ◽

10.1007/bf01408082 ◽

1978 ◽

Vol 287 (2) ◽

pp. 137-142 ◽

Cited By ~ 21

Author(s):

K. Blum ◽

E. E. Fitchard ◽

H. Kleinpoppen

Keyword(s):

Coherent Excitation ◽

Free Region ◽

Field Free Region

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Metastable ion studies. VI. The identification of C2H5N+• ion structures from their characteristic kinetic energy releases

Canadian Journal of Chemistry ◽

10.1139/v76-145 ◽

1976 ◽

Vol 54 (7) ◽

pp. 1007-1014 ◽

Cited By ~ 22

Author(s):

John L. Holmes ◽

Johan K. Terlouw

Keyword(s):

Kinetic Energy ◽

Energy Release ◽

Kinetic Energy Release ◽

Open Chain ◽

Structural Identity ◽

Free Region ◽

Unequivocal Identification ◽

Field Free Region ◽

Labelling Experiment ◽

Precursor Molecules

Metastable peaks for the fragmentation C2H5N+• → C2H4N+ + H• have been studied in the first field-free region of a double focussing mass spectrometer. Isomeric structures of C2H5N+• ions derived from a variety of precursor molecules were characterised by their metastable peak shape and kinetic energy release. The identifications were aided by appropriate deuterium labelling experiments. Four isomeric ionsr [Formula: see text]were shown to retain their structural identity within the ion energy and lifetime ranges observable in these experiments. Ion (a), generated from aziridine was found to be indistinguishable from its open chain isomer [Formula: see text]The results closely parallel those previously found for the isoelectronic C2H5N+• ions, but the differences in characteristic kinetic energy release are smaller. A simple deuterium exchange labelling experiment may be necessary for the unequivocal identification of C2H5N+• ion structures.

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