DEMONSTRATION OF A BPM WITH 5 MICRON RESOLUTION OVER A 10 CM RANGE

At the Free electron LASer in Hamburg (FLASH), six distinct methods to measure the energy of the electron beam have been employed in and around the first bunch compressor chicane. First results from four of the six methods will be presented here and an attempt is made to benchmark all of the measurements against one another. The design and performance of RF phase measurement and EOM sampling schemes for the BPM in the dispersive section of the chicane are also presented in this context. The BPM is required to produce sub-5 um resolution over a 10 cm range, capable of resolving 2*10 -5