TEA CO2 laser induced breakdown versus selective photochemistry in C2F5H and C2F5H/C2F5T mixtures

In the context of laser separation of tritium isotope using C2F5T in mixtur es with C2F5H, we have studied the laser induced dielectric breakdown (LIDB ) as a function of the system pressure using 10.6 mu m radiation of a TEA C O, laser. By taking also into account our isotope selective results, we hav e found that LIDB does not imply difficulties by affecting the laser select ive process. Analysis of the experimental results shows that LIDB works by cascade ionization and the recombination constitutes the major loss process . The LIDB threshold fluence Phi(th) for the tritiated mixture was found to be lower than the corresponding value In pure C2F5H indicating preionizati on in the medium due to beta emission of tritium. (C) 1999 Published by Els evier Science B.V. All rights reserved.