A system and method for peripheral control. A film is mounted directly on the support across the opening, and has a material and a thickness selected to transmit soft x-rays. Analog-to-digital conversion and processing circuits determine multiple electrical parameters with high resolution at a sampling rate sufficient to determine the electrical parameters for approximately each AC cycle. The second reflective surface has a concave cylindrical shape with a projected elliptical profile which is configured to reflect the light beam from the first reflective surface and which defines first and second focal lines.