High-power attosecond X-ray pulses carrying orbital angular momentum (OAM) are promising tools for various scientific applications, including imaging and spectroscopy. Self-seeded free-electron lasers (FELs) with OAM (SSOAM) offer an attractive approach for producing these pulses. In this work, we discuss several aspects concerning the generation of XFEL pulses carrying OAM with a SSOAM setup,...
The FERMI Free Electron Laser in Trieste (Italy) has been designed and built as a seeded source, for precise control of the properties of its light pulses. Its excellent longitudinal coherence is inherited from the seed laser, and is its uppermost distinctive feature. In the realm of atomic, molecular and optical science, the use of longitudinal coherence of laboratory lasers as a time...
Linac-based coherent THz radiation sources are being developed with the NSRRC high brightness photoinjector which has been installed in the Accelerator Test Area (ATA). The injector is equipped with a laser-driven photocathode rf gun and a 5.2-m long S-band traveling-wave linac for beam acceleration. A sub-picosecond electron bunch with 27-MeV beam energy has been produced from this injector...
X-ray free electron lasers (XFELs) offer the capability to produce ultra-intense (>10e12 photons) and ultra-short (few and sub-femtoseconds) x-ray pulses. The exceptional intensity of these pulses enables the massive ionization of core electronic states, resulting in the creation of transient resonances. Despite the inherent challenge posed by the ultra-fast decay time of these transient...
Terahertz/Infrared (THz/IR) radiation and technologies have witnessed incredible development in recent decades owing to their application in a great variety of fields, ranging from scientific research in physics, medicine and biology to research topics closer to our daily lives, such as communications, security or environmental science. In order to push the boundaries of research in all these...
Extreme focusing of XFEL beams is required to achieve power densities needed for applications like single-particle imaging or studies of nonlinear physics. However, focusing optics needs to have high radiation hardness and minimal absorption. We are developing multilayer Laue lenses (MLLs), diffraction-based X-ray optics with which we can focus X-rays to nanometer spot sizes. However, these...
X-ray probes, e.g., X-ray absorption and X-ray emission spectroscopies (XAS and XES, respectively) have the advantage of being sensitive to the electronic configurations and local structures around the absorbing element. They have routinely been employed to study photoexcited states of materials at synchrotron radiation and X-ray Free Electron Laser (XFEL) large-scale facilities. Time resolved...
