Theoretical surface velocity distributions on acoustic splitter geometries for an engine inlet

The potential-flow velocity distributions on several splitter geometries in an engine inlet and their variation with different splitter leading-edge shapes and distances from the inlet highlight were analyzed. The velocity distributions on the inner and outer surfaces of the splitters are presented for low-speed and cruise conditions. At zero incidence angle, the splitter with the 4-to-1 elliptical leading edge had lower peak velocities and velocity gradients than the splitter with the 2-to-1 elliptical leading edge. The velocity gradients decreased as the distance from the inlet highlight to the splitter leading edge was increased. For a given distance, the peak velocity on the splitter inner surface increased with increasing inlet incidence angle. At an incidence angle of 50 deg, the velocity level and gradients on the inner surface of the splitter in the forward position were sufficiently severe to suggest local separation

Diagnostics at the MAX IV 3 GeV storage ring during commissioning

The MAX IV 3 GeV storage ring based on a multibend achromat lattice allows for horizontal emittances from 330 pm rad down to 180 pm rad, depending on the number of insertion devices. The diagnostics used during commissioning will be described, with emphasis on the emittance diagnostics. This will involve two diagnostic beam lines to image the electron beam with infrared and ultraviolet synchrotron radiation from bending magnets, in order to determine also beam energy spread. The scheme for horizontal emittance measurements looks promising also for an order of magnitude lower emittance. Bunch lengthening with harmonic cavities is essential for the low emittance machine performance. We have used a radiation-based sampling technique to verify individual bunch distributions