Publications by authors named "R Tromp"
Energy-Dispersive X-Ray Spectroscopy (EDS) is a technique frequently used in Scanning and Transmission Electron Microscopes to study the elemental composition of a sample. Briefly, high energy electrons of the incident electron beam may ionize an electron from a core shell. The decay of this excited state may result in the emission of a characteristic X-ray photon or Auger-Meitner electron.
View Article and Find Full Text PDFArticle Synopsis
- Connectomics, a method that utilizes large-volume serial electron microscopy, is an essential tool for understanding neural circuits.
- Current imaging techniques like transmission electron microscopy (TEM) and scanning electron microscopy (SEM) have limitations in achieving synaptic resolution.
- The introduction of photoemission electron microscopy (PEEM) offers a new approach that combines fast imaging with high resolution, allowing for efficient circuit mapping in neuroscience.
A new, complementary technique based on Photo Emission Electron Microscopy (PEEM) is demonstrated. In contrast to PEEM, the sample is placed on a transparent substrate and is illuminated from the back side while electrons are collected from the other (front) side. In this paper, the working principle of this technique, coined back-illuminated PEEM (BIPEEM), is described.
View Article and Find Full Text PDFArticle Synopsis
- The paper discusses a new cryogenic sample chamber designed for low energy electron microscopy (LEEM) and shares initial experimental findings.
- Modifications were made to the LEEM instrument to enable cooling mechanisms and minimize heat load, achieving sample temperatures as low as 15 K using liquid nitrogen and helium.
- Initial low-temperature LEEM experiments on a three-monolayer pentacene film revealed a significant decrease in electron beam damage at lower temperatures and changes in the LEEM-IV spectra, with explanations provided for these observations.
Article Synopsis
- The LEEM-IV spectra of few-layer graphene reveal specific energy minima that vary with the number of layers, while low-energy TEM spectra show transmission maxima at those corresponding energy levels.
- The observed patterns in both LEEM and TEM can be explained through electron wave function interference in an elastic scattering model.
- A new model is proposed that incorporates both elastic and inelastic scattering effects, allowing for a self-consistent extraction of Mean Free Path (MFP) values and a comparison with existing research.