Search results for "electrons"
showing 10 items of 1325 documents
Untersuchung verschiedener Elektronenemissionsprozesse auf Mehrfachemission
1965
A comparison of the pulse hight distribution of several electron emission processes is drawn. Thermionic electrons, photoelectrons, field electrons and exoelectrons are found to be emitted as single electrons.
Microscopic quasiparticle-phonon description of odd-mass127−133Xeisotopes and their β decay
1998
Quasiparticle-phonon equations of motion are solved starting from a microscopic realistic many-body Hamiltonian. In this microscopic quasiparticle-phonon model (MQPM) the relevant part of the three-quasiparticle Hilbert space may possibly be taken into account even in calculations using large single-particle bases. As an example, the MQPM is applied to the calculation of energy levels and Fermi and Gamow-Teller beta-decay transition amplitudes for transitions between odd-mass ${}^{127\ensuremath{-}133}\mathrm{Xe}$, ${}^{127\ensuremath{-}133}\mathrm{I}$, and ${}^{127\ensuremath{-}133}\mathrm{Cs}$ isotopes. Considering the fully microscopic nature of the MQPM, comparison of its results and da…
Large-N Weinberg-Tomozawa interaction and spin-flavor symmetry
2006
The construction of an extended version of the Weinberg-Tomozawa Lagrangian, in which baryons and mesons form spin-flavor multiplets, is reviewed and some of its properties discussed, for an arbitrary number of colors and flavors. The coefficient tables of spin-flavor irreducible representations related by crossing between the $s$-, $t$- and $u$-channels are explicitly constructed.
Nachweis der Mehrfachemission von Sekund�relektronen mittels Proportionalz�hlrohr
1965
A proportional counter is used as analyser for electron energies (in the range 10 to 20 keV). The resolving power for 20 keV is 21%. The multiple emission of secondary electrons is investigated with this counter.
Zur Sekund�relektronenemission durch Argonionen und Argonatome im Energiebereich von 1 bis 20 keV
1966
Be-, CuBe-, Cu- and Al-targets are bombarded by single A+ and A0 in the energy range from 1 to 20 keV. The secondary electrons accelerated by 20 keV are counted by a proportional counter backed by a multichannel analyser. The probability distributionPn of emission ofn=0,1, 2, 3, ... secondary electrons can be found from the pulse height distribution. WhenPn is known the yield for A+ and A0 can be calculated. The counting of neutrals in the energy range investigated is discussed.
Nuclear magnetic resonance at millitesla fields using a zero-field spectrometer
2016
We describe new analytical capabilities for nuclear magnetic resonance (NMR) experiments in which signal detection is performed with chemical resolution (via spin-spin J couplings) in the zero to ultra-low magnetic field region, below 1μT. Using magnetic fields in the 100μT to 1mT range, we demonstrate the implementation of conventional NMR pulse sequences with spin-species selectivity.
The large-area micro-channel plate entrance detector of the heavy-ion magnetic spectrometer PRISMA
2005
This paper describes the entrance detector of the magnetic spectrometer PRISMA recently installed at Legnaro. The detector is based on rectangular (80 x 100 mm(2)) Micro-Channel Plates (MCP). It provides a fast time signal and its position-sensitive anode allows to extract the X and Y information. It exploits an electrostatic field for the acceleration of secondary electrons from a thin Carbon foil (similar or equal to 20 mu g/cm(2)) onto the MCP assembly. The electrons are guided by a parallel magnetic field. Good performances were obtained in the laboratory tests. The detector is presently installed at the entrance of PRISMA and gives resolutions <= 400 ps in time, and 1 mm in both X and …
High spin states of120Ba
1991
The very neutron deficient nucleus120Ba has been investigated in a high-spin γ-spectroscopic study. The yrast band of120Ba is extended up to spin 22ħ and one tentatively assigned negative-parity side band is observed up to spin 15ħ. The experimental results are compared with Total Routhian Surface calculations.
Spinrotator for MAMI
1991
A source of polarized electrons based on the photoemission of a GaAsP-cathode [1] has been set up to inject polarized electrons in the Mainz microtron MAMI. In order to compensate the spin precession in MAMI a spinrotator system has to be integrated in the 100 keV beamline from the source to the injector linac to achieve the required longitudinal spin direction at target position.
Tensor Network Annealing Algorithm for Two-Dimensional Thermal States
2019
Tensor network methods have become a powerful class of tools to capture strongly correlated matter, but methods to capture the experimentally ubiquitous family of models at finite temperature beyond one spatial dimension are largely lacking. We introduce a tensor network algorithm able to simulate thermal states of two-dimensional quantum lattice systems in the thermodynamic limit. The method develops instances of projected entangled pair states and projected entangled pair operators for this purpose. It is the key feature of this algorithm to resemble the cooling down of the system from an infinite temperature state until it reaches the desired finite-temperature regime. As a benchmark we …