Photon acceleration as a scattering process

Multiple Scattering as a Diffusion Process

Multiple scattering in participating media is generally a complex phenomenon. In the limit of an optically thick medium, i.e., when the mean free path of each photon is much smaller than the medium size, the effects of multiple scattering can be approximated by a diffusion process. We introduce this approximation from the radiative transfer literature to the computer graphics community and prop...

Charge Asymmetry as a Probe of Two-photon Effects in Elastic Photon-hadron Scattering

We consider the production of a lepton-antilepton pair by real photons off a hadronic target. The interference of one and two photon exchange amplitudes leads to a charge asymmetry term that may be calculated explicitly in the large-t limit in terms of hadronic distribution amplitudes. A rather compact expression emerges for the leading order asymmetry at fixed angle in the centre-of-mass of th...

Hardware acceleration of photon mapping

Photon Acceleration-Based Radiation Sources

The acceleration and deceleration of photons m a plasma provides the means lbr a series of new radiation sources. Previous work on a DC to AC Radiation Converter (DARC source) has shown variable acceleration of photons having zero frequency (i.e., an electrostatic field) to belx~een 6 and 100 GHz (I-3). These sources all had poor guiding characteristics resulting in poor power coupling froln th...

Compton scattering as a probe for materials investigation

This article investigates into the feasibility of using gamma radiation Compton backscatter spectra as a means of material characterization, with the view to developing a portable, hand held probe for investigative purposes such as searching for illicit substances hidden in wall or car door cavities.