We describe design of optimized undulator with SC windings able to generate magnetic field of opposite helicities, including elliptic and a linear ones oriented as desired. For undulator period 25mm, aperture 8mm, length ~10m (single piece), K factor could be changed from zero up to 1.5 by changing the feeding current. 1. OVERVIEW Undulators are planned for installation in all SR facilities. Un...

In the proposed E-166 experiment at SLAC, 50 GeV electrons pass through a helical undulator, and produce circularly polarized photons, which interact with a tungsten target and generate longitudinally polarized positrons. The background is an important issue for an experiment under consideration. To address this issue, simulations were performed with the code GEANT3 to model the production of s...

The feasibility to generate powerful monochromatic radiation of the undulator type in the gamma region of the spectrum by means of planar channeling of ultrarelativistic electrons in a periodically bent crystal is proven. It is shown that to overcome the restriction due to the smallness of the dechanneling length, an electron-based crystalline undulator must operate in the regime of higher beam...

The VISA (Visible to Infrared SASE Amplifier) FEL is designed to obtain high gain at a radiation wavelength of 800nm. The FEL uses the high brightness electron beam of the Accelerator Test Facility (ATF), with energy of 72MeV. VISA uses a novel, 4 m long, strong focussing undulator with a gap of 6mm and a period of 1.8cm. To obtain large gain the beam and undulator axis have to be aligned to be...

A rotatable high-resolution angle-resolved photoemission spectroscopy (ARPES) system has been developed to utilize tunable linear-polarization geometries on the linear undulator beamline (BL-1) at Hiroshima Synchrotron Radiation Center. By rotating the whole ARPES measurement system, the photoelectron detection plane can be continuously changed from parallel to normal against the electric field...

The generation of Free Electron Laser (FEL) radiation relies on the extraction of electromagnetic energy from kinetic energy of a relativistic electron beam by propagating it along the axis of a periodic lattice of alternating magnetic dipolar fields, known as undulator. This forces the beam to undulate transversally, thus causing the electrons to emit electromagnetic radiation. The fundamental...

Terawatt-scale sub-10-fs laser technology – key to generation of GW-level attosecond pulses in X-ray free electron laser Abstract We propose a technique for the production of attosecond X-ray pulses which is based on the use of X-ray SASE FEL combined with a femtosecond laser system. A few-cycle optical pulse from a Ti:sapphire laser interacts with the electron beam in a two-period undulator re...

An electron beam halo monitor has been developed in order to protect undulator permanent magnets against radiation damage for the X-ray free electron laser facility at SPring-8 (XFEL/SPring-8). The halo monitor will be installed at the upstream of the undulator and detect the electron beam that might hit the undulator magnets. Diamond detector, which operates in photoconductive mode, is good ca...

A number of methods for producing sub-picosecond beam microbunching have been developed in recent years. A train of these bunches is capable of generating THz radiation via multiple mechanisms like transition, Cherenkov and undulator radiation. We utilize a bunch train with tunable spacing to selectively excite high order TM0,n modes in a multimode structure. In this paper we present experiment...

The radiation shielding for an Advanced Photon Source (APS) insertion device beamline using a mirror as the first optical component is discussed. The beamline layout for a specific Synchrotron Radiation Instrumentation Collaborative Access Team beamline (sector 2 of SRI CAT) is described, and the methodology used to determine the radiation shielding is presented. Results indicate that, by using...