Speaker
Description
FERMI has started the upgrade phase to FERMI 2.0. The ultimate goal of the upgrade plan is to extend the spectral range of the facility to cover the water window and beyond, and to reduce the minimum pulse duration below the characteristic lifetime of the light element core hole electrons. One of the main requirements of this upgrade is to preserve the uniqueness of FERMI: the possibility to control the properties of the radiation by seeding the FEL with an external laser system.
Much of the upgrade will affect the linac for an increased energy and improved beam quality, and the FEL-2 line. FEL-2 currently operates as a two-stage HGHG FEL. In the future FEL-2 will accommodate a first stage that can be configured as an EEHG FEL and a HGHG second stage with a shorter-period final amplifier. In a first phase of the upgrade, FERMI FEL-1 has been converted to an EEHG configuration and the linac energy was increased to 1.5 GeV at 50 Hz repetition rate (above 1.65 at 10 Hz). The experience with EEHG on the FEL-1 line will be an important step towards the final realisation of the FERMI FEL as a reliable source of highly coherent radiation at ~2 nm and below.
