Highly efficient time-of-flight spectrometer for studying low-energy secondary emission from dielectrics: Secondary-electron emission from LiF film

Abstract

Articles you may be interested inA simple electron time-of-flight spectrometer for ultrafast vacuum ultraviolet photoelectron spectroscopy of liquid solutions Rev. Sci. Instrum. 85, 103117 (2014); 10.1063/1.4899062 Determining time resolution of microchannel plate detectors for electron time-of-flight spectrometers Rev. Sci. Instrum. 81, 073112 (2010); 10.1063/1.3463690 Angle-resolving time-of-flight electron spectrometer for near-threshold precision measurements of differential cross sections of electron-impact excitation of atoms and molecules Rev. Sci. Instrum. 79, 043105 (2008); 10.1063/1.2912824 High resolution time-of-flight spectrometer for crossed molecular beam study of elementary chemical reactions Rev. Sci. Instrum. 76, 083107 (2005); 10.1063/1.1960718High resolution pulsed field ionization photoelectron spectroscopy using multibunch synchrotron radiation: Timeof-flight selection scheme Rev.A highly efficient time-of-flight electron spectrometer is described. An incident electron current of the order of 10 Ϫ14 A makes it suitable for studying secondary emission from dielectric surfaces. A microchannel plate position-sensitive detector allows flight distance correction while keeping a large acceptance angle. Measured energy distribution curves of secondary electrons generated from a LiF film by 19-31 eV incident electrons demonstrate good energy resolution and reveal reproducible and stable emission features at 2.6Ϯ0.3 eV, 7.2Ϯ0.3 eV, and 10.3Ϯ0.3 eV.

Spin-dependent reflection of very-low-energy electrons from W(110)

“…We used a time-of-flight technique for electron energy measurements. 23 The incident electron beam is pulsed with a pulse width less than 1 ns to have a reference point on a time scale. Scattered and ejected electrons are detected by a position-sensitive detector based on 75 mm diameter microchannel plates.…”

Spin-orbit coupling in tungsten by spin-polarized two-electron spectroscopy

“…We use a combination of time-of-flight energy analysis and coincidence technique, which is described elsewhere. 5,20,21 The incident electron beam was pulsed (1 ns pulse width and 2.5ϫ 10 6 Hz repetition rate) to have a reference point on the time scale. Position sensitive detectors allow detection of electrons in a wide angular range as well as a flight distance correction for electrons arriving at different locations on the detectors.…”

Two‐Electron Spectroscopy Versus Single‐Electron Spectroscopy for Studying Secondary Emission from Surfaces

“…Given that the electron affinity of LiF is very small, much smaller than the band gap, the electrons with energy below (10 to 11) eV can probably escape from the solid if their momentum points to the vacuum. It is known that the secondary emission spectrum of a LiF film exhibits "true secondary emission" features at about 7 eV and 11 eV [13]. We analyzed one of these features (7 eV) using a combination of single-electron and two-electron spectroscopies.…”

“…Low energy secondary emission spectra from the LiF film at various primary energies were recorded using Relationship between parallel to the surface components of momenta of the scattered electrons K 1 and K 2 and the momentum of the bound electron q; a) accessible range of q || is determined by the combination of K 1 and K 2 that can be measured; b) combination of K 1 and K 2 that corresponds to the excitation of the valence electron with q || = 0, assuming conservation of the components parallel to the surface. one of the arms of the time-of-flight (e,2e) spectrometer when coincidence conditions were switched off [13]. A set of (e,2e) spectra was measured for the same primary energies.…”

“…A silicon single crystal, with crystallographic plane (001) parallel to the wafer surface, was chosen as a sample. It was chemically cleaned before placing into the vacuum chamber, as described elsewhere [13]. The final stage of the sample cleaning by heating was monitored by LEED and recorded (e,2e) spectra.…”