ATF2 is a final-focus test beam line which aims to focus the low emittance beam from the ATF damping ring to a vertical size of about 37 nm and to demonstrate nanometer level beam stability. Several advanced beam diagnostics and feedback tools are used. In December 2008, construction and installation were completed and beam commissioning started, supported by an international team of Asian, European, and U.S. scientists. The present status and first results are described.
More than twenty institutes join the FCAL Collaboration in study of design of the very forward region of a detector for ILC and CLIC. Of particular importance is an accurate luminosity measurement to the level of 10-3, a requirement driven by the potential for precision physics at a future linear collider. In this paper, the method for luminosity measurement, requirements on luminometer and its integration in the forward region are presented. The impact of several effects contributing to the systematic uncertainty of luminosity measurement is given.
