Radiochemical Applications in Industry – A Journey through Time with RC Tritec

Over the course of time, radioactive applications have changed from miracle cures to a material that is treated with caution in public perception. As a Swiss company, which has always been working with radioactive materials, RC Tritec is an interesting example how the applications in private industry have changed over the years: The company was originally a Ra-226 activated luminous paint manufacturer which managed to become a leader in the field of tritium labelling, the construction of manifolds for the handling of ionizing gases, source production and neutron imaging.

Transient decomposition-recombination dynamics of dissociating and ionizing gases

A generic gas AB, initially at a relatively high temperature, undergoes a spatially homogeneous, constant-volume decomposition-recombination reaction represented by AB + M ⇌ A + B + M. The complete time-history of this variable temperature reaction is calculated by employing high activation energy asymptotic analysis developed originally for thermal explosion problems. The evolution of the reaction is described in terms of an initiation period with small changes in the mixture temperature and composition, a longer major decomposition period during which most of the conversion of AB to A and B occurs, and an extended final period during which recombination becomes important as the system relaxes to the equilibrium state. Explicit timescales are derived for each of the distinct reaction processes. The analytically derived solution agrees quantitatively with the numerical solution and qualitatively with experimental results.

Numerical Calculations on Reflection Processes of Ionizing Shocks on the End Wall of a Shock Tube

Numerical calculations have been made about shock reflection processes in ionizing argon on the end wall of a shock: tube. The two-step Lax-Wendroff scheme was employed to solve time-dependent one-dimensional inviscid flow problems for ionizing gases. Complicated flowfields were found to occur due to interactions between ionization relaxation processes and reflected shocks. Calculations were performed for three cases: incident-shock Mach number M s = 16 and initial pressure p1 = 1 torr; Ms = 14 and p1 = 3 torr; M s = 12 and p1 = 5 torr.