Richard D'Arcy

Abstract:

FLASHForward (FFV∗-) is the Future-ORiented Wakefield Accelerator Research and Development project at the DESY free-electron laser (FEL) facility FLASH. It aims to produce high-quality, GeV-energy electron beams over a plasma cell of a few centimeters. The plasma is created by means of a 25 TW Ti: Sapphire laser system. The plasma wakefield will be driven by high-current-density electron beams extracted from the FLASH accelerator. The project focuses on the advancement of plasma-based particle acceleration technology through the exploration of both external and internal witness-beam injection schemes. Multiple conventional and cutting-edge diagnostic tools, suitable for diagnosis of short electron beams, are under development. The design of the post-plasma beamline sections will be finalized based on the result of these aforementioned diagnostics. In this paper, the status of the project, as well as the progress towards achieving its overarching goal of demonstrating FEL gain via plasma wakefield acceleration, is discussed.

Abstract:

The SwissFEL project, under commissioning at the Paul Scherrer Institut (PSI), will produce FEL radiation for soft and hard X-rays with pulse durations ranging from a few to several tens of femtoseconds. A collaboration between DESY, PSI and CERN has been established with the aim of developing and building an advanced X-Band transverse deflection structure (TDS) with the new feature of providing variable polarization of the deflecting force. As this innovative CERN design requires very high manufacturing precision to guarantee highest azimuthal symmetry of the structure to avoid the deterioration of the polarization of the streaking field, the high-precision tuning-free assembly procedures developed at PSI for the SwissFEL C-band accelerating structures will be used for the manufacturing. Such a TDS will be installed downstream of the undulators of the soft X-ray beamline of SwissFEL and thanks to the variable polarization of the TDS it will be possible to perform a complete characterization of the 6D phase space. We summarize in this work the status of the project and its main technical parameters.

Abstract:

The PXIE accelerator [1] is the front-end test stand of the proposed Proton Improvement Plan (PIP-II) [2] initiative: a CW-compatible pulsed H-superconducting RF linac upgrade to Fermilab's injection system. The PXIE Ion Source and Low-Energy Beam Transport (LEBT) section are designed to create and transfer a 1-10 mA H-beam, in either pulsed (0.001-16 ms) or DC mode, from the ion source through to the injection point of the RFQ. This paper discusses the range of diagnostic tools - Allison-type Emittance Scanner, Faraday Cup, Toroid, DCCT, electrically isolated diaphragms - involved in the commissioning of the beam line and preparation of the beam for injection into the RFQ.

Abstract:

This chapter discusses the observation of intense XUV emission generated from a hollow cathode micro-discharge source. The emission in the 40 nm XUV spectral region has been characterized from capillary discharge and laser-produced plasmas containing potassium ions with time-averaged electron temperatures of 12 eV and electron densities of 1020 cm-3. Atomic structure calculations with the Cowan code together with available spectral data were used to generate theoretical spectra to compare with the observed emission.