Mary PW Chin 钱碧慧博士
PhD (Wales), MSc (Surrey)


FTREE is an interactive catalogue of complete radiation cascades. It is a creative use of Monte Carlo simulations. Simulations are intercepted to access instantaneous values of the desired attributes before they get over-written as the simulation progress. Interceptions are passive; none modifies the physics or transport in any way. Rigorous post-processing spins out the awesome family trees. FTREE is not a Monte Carlo radiation transport code. Thus named, with F for FLUKA, and TREE in honour of the most enduring DOS command.

Beginning from a single particle impinging matter, each progeny is tracked under real-life irradiation conditions until it is fully absorbed or goes below preset energy thresholds. The ensuing radiation field is characterised interaction by interaction, accounting for nth secondaries producing (n+1)th secondaries, recursively, in a full inventory from upstream all the way downstream. Each progeny is uniquely differentiated into a family tree, indented by the nth generation of the particle, rooting from the single source particle as the first foreparent. The kinship, no less complicated than real life, between each particle is uniquely identified without ambiguity. This mode of scientific observation, analysis and presentation goes beyond:

FTREE also offers a unique opportunity to observe rare events far out in the Gaussian tail which would have been washed out by averaging; such are the events less probable, but no less correct in physics compared to highly probable events populating the Gaussian peak.

The idea for FTREE was first conceived at a workshop, where the maiden work, Carbon stories in calcium, was presented. This was followed by some early developments:

Later, at the International Nuclear Chemistry Congress in Brazil, FTREE found herself a novel experiment technique as much as a novel teaching resource. The reference paper is here: Single-history Monte Carlo analysis for radiation detection and measurement 2015 J Radioanal Nucl Chem.

Snapshot from CERN: the horizontal n_TOF tunnel
tracks from the horizontal n_TOF tunnel
The vertical (new) n_TOF beamline
tracks from the vertical n_TOF beamline
480 MeV proton on tungsten: the bold
tracks from a proton-on-tungsten spallation neutron source
480 MeV proton on tungsten: the beautiful
tracks from a proton-on-tungsten spallation neutron source
Carbon therapy of a human brain
tracks from carbon therapy of a virtual human brain