Secondary-electron yield as a probe of preequilibrium stopping power of heavy ions colliding with solids

Koschar, P.; Kroneberger, K.; Clouvas, A.; Burkhard, M.; Meckbach, W.; Heil, O.; Kemmler, J.; Rothard, H.; Groeneveld, K. O.; Schramm, R.; Betz, Hans Dieter

doi:10.1103/physreva.40.3632

Cited by 52 publications

(30 citation statements)

References 18 publications

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“…As observed by Koschar et al [24], the secondary electron yield for 12 MeV 12 C ions is saturated for a carbon foil thickness over 15 lg/cm 2 , while at 3 and 10 lg/cm 2 the electron emission is already 65% and 90% of the maximum, respectively. On the other hand thinner foils are preferred for a smaller energy straggling and MS. Consequently, a compromise of the optimal carbon foil thickness is then required.…”

Section: Detection Efficiencymentioning

confidence: 57%

Low-energy heavy-ion TOF-ERDA setup for quantitative depth profiling of thin films

Giangrandi

Sajavaara

Brijs

et al. 2008

Nuclear Instruments and Methods in Physics Research Section B:

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Section: Detection Efficiencymentioning

confidence: 57%

Low-energy heavy-ion TOF-ERDA setup for quantitative depth profiling of thin films

Giangrandi

Sajavaara

Brijs

et al. 2008

Nuclear Instruments and Methods in Physics Research Section B:

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“…The electron emission from both surfaces (entrance and exit) of the target is called total emission (and the total yield is denoted by Y T , where the total secondary-electron yield is the sum of the backward yield and forward yield (Y T = Y B + Y F ) [Potiriadis et al, 2005]. Koschar et al [1989] separated the secondary electrons in two groups: (1) 5.2. The emission of secondary electrons from a thin foil bombarded with protons low-energy secondary-electrons excited in distant collisions and (2) high-energy δ-electrons excited in close collisions.…”

Section: The Emission Of Secondary Electrons From a Thin Foil Bombardmentioning

confidence: 99%

“…For a target of thickness d, the forward and backward secondary-electron yields are reported in equations 5.2 and 5.3, respectively [Koschar et al, 1989].…”

Section: The Emission Of Secondary Electrons From a Thin Foil Bombardmentioning

confidence: 99%

Development of a PET cyclotron based irradiation setup for proton radiobiology

et al. 2015

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An out-of-yoke irradiation setup using the proton beam from a cyclotron that ordinary produces radioisotopes for positron emission tomography (PET) has been developed, characterized, calibrated and validated. The current from a 20 µm thick aluminum transmission foil is readout by home-made transimpedance electronics, providing online dose information. The main monitoring variables, delivered in real-time, include beam current, integrated charge and dose rate. Hence the dose and integrated current delivered at a given instant to an experimental setup can be computercontrolled with a shutter. In this work, we report on experimental results and Geant4 simulations of a setup which exploits for the first time the 18 MeV proton beam from a PET cyclotron to irradiate a selected region of a target using the developed irradiation system. By using this system, we are able to deliver a homogeneous beam on targets with 18 mm diameter, allowing to achieve the controlled irradiation of cell cultures located in biological multi-well dishes of 16 mm diameter. We found that the magnetic field applied inside the cyclotron plays a major role for achieving the referred to homogeneity. The quasi-Gaussian curve obtained by scanning the magnet current and measuring the corresponding dose rate must be measured before any irradiation procedure, with the shutter closed. At the optimum magnet current, which corresponds to the center of the Gaussian, a homogenous dose is observed over the whole target area. Making use of a rotating disk with a slit of 0.5 mm at a radius of 150 mm, we could measure dose rates on target ranging from 500 mGy/s down to 5 mGy/s. For validating the developed irradiation setup, several Gafchromic R EBT2 films were exposed to different values of dose. The absolute dose in the irradiated films were assessed in the 2D film dosimetry system of the Department of Radiotherapy of Coimbra University Hospital Center with a precision better than 2%. In the future, we plan to irradiate small animals, cell cultures, or other materials or samples.

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“…Since it is not known whether these are surface or subsurface layers, it is important to consider the basic mechanisms involved in particle-induced electron emission. Electron ejection from a solid can be considered as a three-step process [17]: (1) production of excited electrons, (2) transport of electrons through the solid, and (3) escape of electrons from the surface. The dependence of the electron emission efficiency on the specific trajectories of the scattered particles results in an increasing probability for detection of scattered particles that emit more electrons along their trajectory.…”

Section: Mechanisms Of Particle-induced Electron Emissionmentioning

confidence: 99%

Electron-ion/atom coincidence measurements of 3keV He+ interacting with a SiH(100)-(2×1) surface

et al. 2005

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Secondary-electron yield as a probe of preequilibrium stopping power of heavy ions colliding with solids

Cited by 52 publications

References 18 publications

Low-energy heavy-ion TOF-ERDA setup for quantitative depth profiling of thin films

Low-energy heavy-ion TOF-ERDA setup for quantitative depth profiling of thin films

Development of a PET cyclotron based irradiation setup for proton radiobiology

Electron-ion/atom coincidence measurements of 3keV He+ interacting with a SiH(100)-(2×1) surface

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