2 research outputs found
Cascade infrared thermal photon emission
The time development of the excitation energy of molecules and clusters
cooling by emission of thermal vibrational infrared radiation has been studied.
The energy distributions and the photon emission rates develop into
near-universal functions that can be characterized with only a few parameters,
irrespective of the precise vibrational spectra and oscillator strengths of the
systems. The photon emission constant and emitted power averaged over all
thermally populated states vary linearly with total excitation energy with a
small offset. The time developments of ensemble internal energy distributions
are calculated with respect to their first two moments. For the derived linear
dependence of the emission rate constant, these results are exact
Velocity Map Imaging with No Spherical Aberrations
Velocity map imaging (VMI) is a powerful technique that allows to infer the
kinetic energy of ions or electrons that are produced from a large volume in
space with good resolution. The size of the acceptance volume is determined by
the spherical aberrations of the ion optical system. Here we present an
analytical derivation for velocity map imaging with no spherical aberrations.
We will discuss a particular example for the implementation of the technique
that allows using the reaction microscope recently installed in the Cryogenic
storage ring (CSR) in a VMI mode. SIMION simulations confirm that a beam of
electrons produced almost over the entire volume of the source region, with
width of 8 cm, can be focused to a spot of 0.1 mm on the detector. The use of
the same formalism for position imaging, as well as an option of position
imaging in one axis and velocity map imaging in a different axis, are also
discussed