NEW GAS-PHASE EXPERIMENT AT THE NORMAL INCIDENCE BEAM LINE AT MAX

We have recently started a new program to study ion fragments from photoionization and photodissociation processes, using synchrotron radiation at the normal incidence beam line at the electron storage ring MAX in Lund, Sweden. The experimental chamber is connected to the beam line via a simple arrangement consisting of a glass capillary with approximately 25% transmission in the wavelength region 300-700 angstrom, leading through a differential pumping stage. This arrangement allows us to operate the target gas chamber at pressures of 1-3.10(-5) Torr. The design and performance of this new experiment is presented as well as examples of the first results from experiments on diatomic molecules and noble gases. In particular, it has been possible to record ion spectra with sufficient resolution and intensity to permit a detailed line profile analysis of autoionization resonances.