Measurement of Cl and Br photofragment alignment using slice imaging

Slice imaging is used to measure directly the alignment of Br(P-2(3/2)) and Cl(P-2(3/2)) photofragments from the photodissociation of Br-2 and Cl-2, respectively, at 355 nm, using an intensity-normalization method that does not require the wavelength scanning of the probe laser. In both cases the C (1)Pi(1(u)) state is optically excited. The Br photofragments are maximally aligned and populate m(J)=+/-1/2 only, whereas the Cl photofragments populate both the m(J)=+/-1/2 and m(J)=+/-3/2 by 80% and 20%, respectively. These results show that Br-2 dissociates adiabatically, whereas nonadiabatic transitions occur to the A (3)Pi(1(u)) during Cl-2 dissociation. (C) 2002 American Institute of Physics.