Three kinds of research are pursued in the molecular beam laboratory: 1. High-precision studies of atomic and molecular hyperfine structure, an example being the recent discovery and measurement of an octopole interaction in the bromine atom. 2. The development of atomic frequency standards by using atomic and molecularbeam techniques. The carbon monoxide electric resonance studies and the ammo...

A myriad of advances in microscope stability, aberration correction and improved detectors now make it routinely possible to achieve atomic resolution energy dispersive X-ray (EDX) mapping [1], showing atomic-scale qualitative detail as to where the elements reside within a sample. Whenever we analyse crystals down a low-order zone axis we are exploiting electron channelling to provide us with ...

Rapid development of magnetic nanotechnologies calls for experimental techniques capable of providing magnetic information with subnanometre spatial resolution. Available probes of magnetism either detect only surface properties, such as spin-polarized scanning tunnelling microscopy, magnetic force microscopy or spin-polarized low-energy electron microscopy, or they are bulk probes with limited...

The use of a TEMoi*-mode laser beam has been proposed as a means of focusing an atomic beam to nanometerscale spot diameters. We have analyzed the classical trajectories of atoms through a TEM01*-mode laser beam, using methods developed for particle optics. The differential equation that describes the properties of the firstorder paraxial lens has exactly the same form as the bell-shaped magnet...

The HERMES hydrogen target was operated during 1996 and 1997 in the HERA electron ring at DESY to study the spin structure of the proton by deep inelastic lepton proton scattering. An Atomic Beam Source (ABS) injects an atomic hydrogen beam of high intensity and high proton polarization into a storage cell, made of thin aluminum and coated with Driilm. A sampling tube attached on the side of th...

We present a theoretical analysis of the evaporative cooling of a magnetically guided atomic beam by means of discrete radio-frequency antennas. First we derive the changes in flux and temperature, as well as in collision rate and phase-space density, for a single evaporation step. Next we show how the occurrence of collisions during the propagation between two successive antennas can be probed...

The design of a novel-type of atomic beam source which provides for long term, stable operation at high emission rates is reported. The heart of the design is the “candlestick” where liquid source material is transported by capillary action to a localized hot emission region. A surrounding cavity kept at the melting point for the source material shields the vacuum chamber walls from this region...

N+-bombarded multi-walled carbon nanotubes (N+-bombarded MWCNTs), with different nitrogen atomic percentages, were achieved by different N ion beam currents using ion beam-assisted deposition (IBAD) on MWCNTs synthesized by chemical vapor deposition (CVD). Characterizations of N+-bombarded MWCNTs were evaluated by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), R...

Structural characterisation of individual molecules by high-resolution transmission electron microscopy (HRTEM) is fundamentally limited by the element and electron energy-specific interactions of the material with the high energy electron beam. Here, the key mechanisms controlling the interactions between the e-beam and C-H bonds, present in all organic molecules, are examined, and the low ato...

Quantum interference is shown to deliver a means of regulating the diffraction pattern of a thermal atomic beam interacting with two standing wave electric fields. Parameters have been identified to enhance the diffraction probability of one momentum component over the others, with specific application to Rb atoms. PACS number(s): 32.80 Qk, 34.50 Dy, 39.20 +q, 39.25 +k, 03.75 Dg Typeset using R...