Abstract
Novel techniques of flash photolysis experiments require high intensity light sources in the near UV. We describe here a simple and inexpensive flash device which may compete with bulky and expensive laser systems if the experiments do not necessitate very short light pulses. Using a particular optical arrangement and stored electrical energy, a variation of the parameters voltage and capacitance led to a difference in light output by a factor of more than two. The system is used to relax both skeletal and smooth muscle fibres in the rigor state by releasing up to 2 mM ATP from 12.5 mM caged-ATP.