Electron ejection from beam-tilted-foil experiments
TL;DR: In this article, the total yield of secondary electrons (SE) emitted during the passage of heavy ions through thin C-foils with incident energies in the MeV range has been measured by a simple method.
About: This article is published in Nuclear Instruments and Methods.The article was published on 1978-05-15. It has received 20 citations till now. The article focuses on the topics: Secondary electrons & Projectile.
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TL;DR: In this article, a novel interference effect of electron density waves in a solid was reported. But the interference was not considered in the analysis of the total electron yield in the ion-solid interaction.
31 citations
TL;DR: In this article, an interference on the wake potentials induced in the solid by the two Coulomb-exploding nuclear fragments is explained by a strong molecular effect on the total electron emission.
Abstract: Measurements of low energy electron spectra and the total electron yield γ from energetic E/M > 20 keV/U ion/solid-interaction are used to obtain information on electron production and emission processes. The data for monoatomic projectile ions can be explained in the framework of current theories. Comparing the isotachic yields γ of atomic and molecular projectile ions a strong molecular effect on the total electron emission is found. It is explained by an interference on the wake potentials induced in the solid by the two Coulomb-exploding nuclear fragments. From these data the wake wavelength or the plasma frequency of the electron in the solid can be calculated.
28 citations
15 Jun 1986-Nuclear Instruments & Methods in Physics Research Section A-accelerators Spectrometers Detectors and Associated Equipment
TL;DR: In this article, a phase space compression technique applicable to short-lived particles is proposed, which treats each single particle separately by measuring its phase via position sensitive particle detectors and steers it via pulsed electromagnetic deflection.
Abstract: A phase space compression technique applicable to short-lived particles is proposed. Its specific feature is that it treats each single particle separately by measuring its phase via position sensitive particle detectors and steers it via pulsed electromagnetic deflection. By applying the method to muons, very high quality low energy beams can be obtained. A specific design is presented that should allow to achieve a 50 keV muon beam with 0.1π mm mrad transverse emittance and 104 s−1 intensity. These muons can be further decelerated to ultralow energies so that for example a 50 eV beam with 3π mm mrad and Δp/p = 10−3 is obtained. The overall phase space compression compared to the entrance beam exceeds 1015. With such beams, stopping of muons in atomic beams or on the first atomic layer of a solid can be envisioned. A short list of possible physics applications is given.
27 citations
01 Jan 1988-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: In this article, the secondary electron emission from both entrance (γb) and exit (γf) surfaces of thin carbon foils traversed by H+, H0 and H+2 projectiles was measured simultaneously.
Abstract: We report experimental work on secondary electron emission from both entrance (γb) and exit (γf) surfaces of thin carbon foils traversed by H+, H0 and H+2 projectiles (1.2 MeV/u). Secondary electron coefficients γb and γf, were measured simultaneously. The results are discussed in the framework of a semiempirical model for kinetic emission of target electrons from solid surfaces.
26 citations
02 Feb 1992-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: The hydrogen detection efficiency using the ERD-TOF technique based on the use of 10 μg/cm2 carbon foil as a start detector was measured with respect to the second conventional ERD detector with an absorber placed at nearly comparable geometry in the same experiment as mentioned in this paper.
Abstract: The hydrogen detection efficiency using the ERD-TOF technique, based on the use of 10 μg/cm2 carbon foil as a start detector, was measured with respect to the second conventional ERD detector with an absorber placed at nearly comparable geometry in the same experiment. The probing beams were 30 MeV 35Cl and 4 MeV 4He, with a detection angle of 30 ° with equal entrance and exit angles with respect to the target surface. From the studies of films of Mylar, Kapton and deuterated polyethylene as well as PECVD a-Si:H, Si3N4, and a-C:H targets, the ERD-TOF hydrogen efficiency was found to be ∼ 40% at 2.43 MeV hydrogen recoils, which increased gradually at lower energies. The hydrogen detection efficiency was also studied as a function of the MCP detector bias by scattering 1 and 3 MeV protons from a thin (100 A) Au film. The energy variation in the efficiency using nearly saturated MCP detector bias was found to be proportional to the energy loss ( d E d x ) of protons in the carbon. A considerable improvement in the efficiency was noted by coating the carbon foil with a thin low density MgO layer. The hydrogen depth profiles using the ERD-TOF technique show better depth resolution and an increased accessible depth than the ERD using absorber. The improved depth resolution, along with the intrinsic ability of the ERD-TOF technique to completely resolve the light element recoils, can be applied in many fields such as the study of hydrogen diffusion in double layer LPCVD Si3N4 structures and polymer diffusions with lower diffusion coefficients.
23 citations
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TL;DR: In this article, the authors analyzed the physical mechanism of secondary electron emission under the impact of high-speed heavy particles and showed that the yield is proportional to the rate of energy loss of the incident particles.
Abstract: The physical mechanism of secondary electron emission under the impact of high-speed heavy particles is analyzed. The treatment is based on the formation of secondaries according to the Bohr-Bethe theory of ionization, the diffusion of the slow secondaries to the surface, and their subsequent escape in the vacuum. The yield is found to be proportional to the rate of energy loss of the incident particles, and it is shown to be essentially the same for all metals, independent of their work function, conductivity, and other bulk properties. The observed energy distribution of the secondaries, the effect of adsorbed layers and the dependence of the yield on temperature, particle charge, and velocity are found to be explained in terms of this mechanism. The application to the general problem of the escape of electrons from metals and to the study of electron capture and loss by ions passing through solids is discussed.
422 citations
TL;DR: In this article, a system for the detection of secondary electrons which are emitted when ions pass through foils was described for detecting heavy ions in a similar way as a d E /d x -detector.
63 citations
23 citations