The multiphoton absorption and decomposition of fluoroform-d: Laser isotope separation of deuterium

Multiphoton absorption (MPA) studies of fluoroform‐d, a molecule of interest for potential laser based hydrogen isotope separation processes, are reported for ${\mathrm{CDF}}_3$ pressures 0.2–1.3 kPa, and for a variety of 10 μm ${\mathrm{CO}}_2$ laser lines with pulse widths of 2 or 6 ns and fluences within the range ${10}^{\text{−3}}\text{–70\hspace{0.17em}}{\mathrm{J/cm}}^2.$ Unlike ${\mathrm{SF}}_6,$ no red shift of the MPA spectrum relative to the small signal spectrum was observed at high fluence. Selective multiphoton decomposition (MPD) experiments using the $\text{10R(26)}$ line, 6 ns pulse to excite the ${\mathrm{CDF}}_3$ component in natural‐abundance ${\mathrm{CHF}}_3\text{\hspace{0.17em}(∼\hspace{0.17em}150\hspace{0.17em}}\mathrm{ppm}\hspace{0.17em}\mathrm{D/H})$ at a pressure of 13.3 kPa resulted in the recovery of water enriched up to 30% in deuterium—a measured isotope enrichment of ⩾2000 fold. This demonstrates that a product, highly enriched in deuterium, can be recovered from the selective MPD of fluoroform.