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Showing 1 to 20 of 34 for “"penning"”.
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Penning trap mass spectroscopy at 0.1 ppb
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1993.
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Penning ionization studies using a crossed-beam technique
… crossed-beam apparatus for the investigation of Penning ionization at thermal energies has been designed and constructed. Details are given for the production of a beam of helium metastable atoms by electron impact excitation. The production of well-collimated neutral beams of stable species …
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The penning trap electron gun for the KATRIN experiment
… the calibration sources for this experiment: the Penning trap electron gun. This calibration source will use ion storage techniques usually used in high resolution mass spectroscopy to store and excite electrons to a known energy and then release them with a user-controlled angular distribution. …
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Examining the Effects of Penning on Juvenile Eastern Box Turtles (Terrapene carolina carolina)
… one: forcing turtles to overwinter on site by penning them in an outdoor enclosure. Two sets of juvenile box turtles were released at the Virginia Commonwealth University Rice Center: one penned on site in a pen for one year, the other allowed to move freely. Our objective was to compare a …
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A mass measurement of the short-lived halo nucleus ¹¹Li with the TITAN Penning trap spectrometer
… were made using recently commissioned TITAN Penning trap mass spectrometer at TRIUMF. The measurement of the halo nucleus ¹¹Li represents a new standard in Penning trap mass spectrometry, as it is the shortest lived, t₁/₂ = 8.8 ms, isotope ever weighed using this technique. Low energy, E = 20 …
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A study of the accuracy of the Penning trap mass spectrometer ISOLTRAP and Standard-Model tests with superallowed beta decays
ISOLTRAP ist ein Penningfallen-Massenspektrometer, das an dem on-line Isotopenseparator ISOLDE/CERN installiert ist. Es dient der Messung der atomaren Massen von kurzlebigen radioaktiven Nukliden. Die statistischen Meßungenauigkeiten einzelner Massenmessungen erreichen in etwa 10E-8. Mit Hilfe von …
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Nested Well Plasma Traps
… of a positive and negative component in Penning type traps with nested electric potential wells are presented. Computational techniques for the self-consistent calculation of potential and plasma density distributions are developed. Analyses are presented of the use of nested well Penning …
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A sub-ppb measurement of the mass of cesium for a new determination of the fine-structure constant
This thesis describes recent single-ion Penning trap mass spectrometry measurements of the mass of atomic Cesium with a relative uncertainty of 2 x 10-10. This measurement reduces the uncertainty on the mass of Cesium by a factor of 100, and removes this uncertainty as a limitation on the accuracy …
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First on-line mass measurements at SHIPTRAP and mass determinations of neutron-rich Fr and Ra isotopes at ISOLTRAP
… a superconducting magnet with two cylindrical Penning traps at a field strength of 7 T. In this work the Penning trap system has been installed and extensively characterized. The first on-line mass measurements of short-lived nuclides were carried out and the masses of 147Er and 148Er could be …
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A new ion beam cooler and buncher for ISOLTRAP and mass measurements of radioactive argon isotopes
… of radioactive argon isotopes - ISOLTRAP is a Penning trap mass spectrometer installed at ISOLDE/CERN. It is set up to measure the mass of short-lived nuclides with a relative accuracy delta m / m of typically 1* 10^-7. In this work an ion beam cooler and buncher based on a linear radio …
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Two-ion control and polarization forces for precise mass comparisons
… done by simultaneously confining two ions in a Penning trap, and simultaneously comparing their cyclotron frequencies which are inversely proportional to the masses. The precision of the previous technique of alternately trapping the two ions was completely limited by magnetic field noise. Our …
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On the Variability of the Fine Structure Constant
… the time dependence of alpha using particles in Penning traps is compared to the results obtained by existing methods, including those using astrophysical data and those obtained in atomic clock experiments. Suggestions are made on the nature of trapped particles and the trapping fields.
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The buffer-gas cell and the extraction RFQ for SHIPTRAP
… to cool and accumulate the ions and a tandem Penning-trap system for isobaric purification and high-precision mass measurements. The buffer-gas cell and the extraction RFQ were developed, assembled and tested within this thesis at the MLL in Garching and at the GSI.
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Cold trapped positrons and progress to cold antihydrogen
… The cooling takes place in a 4.2 K, nested Penning trap where conditions are ideal for the eventual goal of the formation of antihydrogen.
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Characterization and applications of pulsed millisecond glow discharge sources
… the separation of electron-ionized species from Penning ionized species. Penning ionization is a relatively soft ionization process, where analyte molecules are ionized by collisions with metastable argon atoms. In pulsed glow discharge plasmas these two processes are separated both temporally …
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Using the method of moments and Robin Hood method to solve electromagnetic scattering problems
… used for the KATRIN experiment to ensure that no Penning traps occur in the electron spectrometer.
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Experimental Investigation of a Rubidium-Argon Dual Species Magneto-Optical Trap
… losses, for an <sup>40</sup>Ar* MOT it is due to Penning and associative ionization losses. An Ar* PI/AI ionization ratio of 6.7 ± 3.6 was determined, which makes the Penning ionization rate the dominant loss mechanism. The ionization rate was obtained with a SRS RGA200 mass spectrum analyzer …
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Surface studies using spin-polarized ion neutralization spectroscopy
… be explained using the traditional Auger or Penning processes. A model is proposed in which the He+ forms a collision complex with one or more CO 2 molecules in the surface layer, making it energetically possible for an electron to be ejected.
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Direct mass measurements beyond the proton drip-line
At GSI in Darmstadt the Penning trap spectrometer SHIPTRAP was set up to perform precision experiments with low-energetic radioactive ions produced in fusion-evaporation reactions at the velocity filter SHIP. First high-precision measurements were performed determining the masses of 18 …
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