Search

At the Photo Injector Test facility at DESY, Zeuthen site (PITZ), high brightness electron sources for linac based Free Electron Lasers (FELs), like FLASH and the European XFEL are developed and characterized. The electrons are generated via the photoeffect at a cesium telluride (Cs₂Te) cathode and are accelerated by a 1.6-cell L-band RF-gun cavity with an accelerating gradient at the cathode of about 60 MV/m. The profile of the cathode laser pulse has been optimized yielding small emittances using laser pulse shaping methods. The transverse projected emittance is measured by a single slit scan technique. The measurement program in the last run period at PITZ concentrated on emittance measurements for the nominal 1 nC beam and emittance optimization for lower bunch charges. The recent results show that normalized projected emittances of about 1 mm-mrad for 1 nC charge and below 0.5 mm-mrad for 250 pC bunch charges can be realized at PITZ. The facility setup and measurement results including the uncertainty of the measured values will be reported and discussed in this contribution., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The Photo Injector Test facility at DESY, Zeuthen site (PITZ), develops, optimizes and characterizes high brightness electron sources for free electron lasers like FLASH and the European XFEL. In the last year, the facility was significantly upgraded by the installation of a new normal conducting radio- frequency (RF) gun cavity with its new waveguide system for the RF feed, which should allow stable and reliable gun operation, as required for the European XFEL. Other relevant additions include beamline modifications for improving the electron beam transport through the PITZ accelerator, extending the beam-based measurement capabilities, and preparing the installation of a plasma cell. Furthermore, the laser hutch was re-arranged in order to be able to house an additional, new photo cathode drive laser system which should be able to produce 3D ellipsoidal laser pulses to further improve the electron beam quality. This paper describes in detail the aforementioned facility upgrades and reports on the first operation experience with the new gun setup., Proceedings of the 6th Int. Particle Accelerator Conf., IPAC2015, Richmond, VA, USA

3rd European Advanced Accelerator Concepts Workshop, EAAC 2017, Elba, Italy, 24 Sep 2017 - 29 Sep 2017; Nuclear instruments & methods in physics research / A 909, 239 - 242 (2018). doi:10.1016/j.nima.2018.01.036, We present a status update on the dedicated R&D facility SINBAD which is currently under construction at DESY. The facility will host multiple independent experiments on the acceleration of ultra-short electron bunches and novel, high gradient acceleration methods. The first experiment is the ARES-experiment with a normal conducting 100 MeV S-band linac at its core. We present the objectives of this experiment ranging from the study of compression techniques to sub-fs level to its application as injector for various advanced acceleration schemes e.g. the plans to use ARES as a test-site for DLA experiments in the context of the ACHIP collaboration. The time-line including the planned extension with laser driven plasma-wakefield acceleration is presented. The second initial experiment is AXSIS which aims to accelerate fs-electron bunches to 15 MeV in a THz driven dielectric structure and subsequently create X-rays by inverse Compton scattering., Published by Elsevier, Amsterdam

At the Photo Injector Test Facility at DESY in Zeuthen (PITZ) high-brightness electron sources are optimized for use at the X-ray free-electron lasers FLASH and European XFEL. Transverse projected emittance measurements are carried out by a single-slit scan technique in order to suppress space charge effects at an energy of ~20 MeV. Previous slice emittance measurements, which employed the emittance measurement in conjunction with a transverse deflecting structure, suffer from limited time resolution and low signal-to-noise ratio (SNR) due to a long drift space from the mask to the observation screen. Recent experimental studies at PITZ show improvement of the temporal resolution and SNR by utilizing quadrupole magnets between the mask and the screen. The measurement setup is described and first results are shown., Proceedings of the 8th International Beam Instrumentation Conference, IBIC2019, Malmö, Sweden

For successful operation of X-ray Free Electron Lasers, one crucial parameter is the ultrashort electron bunch length yielding a high peak current and a short saturation length. In order to effectively compress the bunches during the acceleration process, a detailed understanding of the full longitudinal phase space distribution already in the injector is required. Transverse deflecting RF structures (TDS) can shear the bunch transversely, mapping the longitudinal coordinate to a transverse axis on an observation screen downstream. In addition to the bunch length, the slice emittance along the bunch as well as the full longitudinal phase space can be obtained. At the Photo Injector Test Facility at DESY, Zeuthen site (PITZ), an S-band traveling wave TDS is under commissioning since 2015. This cavity is a prototype for the TDS in the injector part of the European XFEL and has been designed and manufactured by the Institute for Nuclear Research (INR, Moscow, Russia). In this paper, first commissioning results of the system at PITZ are presented and discussed., Proceedings of the 37th International Free Electron Laser Conference, FEL2015, Daejeon, Republic of Korea

The self-modulation of long particle beams in a plasma has recently gained interest in light of the ongoing preparation for the plasma wakefield acceleration experiment of the AWAKE collaboration at CERN. Instrumental to the experiment is the self-modulation of a proton beam to generate bunches short enough for producing high acceleration fields. As electron bunches are easier to handle and the underlying physics is identical, it is judicious to first gain insight into the experimental conditions of the self-modulation of long particle beams in plasma by using electron bunches before progressing to the experiment with proton bunches. The experimental demonstration of self-modulation of an electron bunch is in preparation at the Photo Injector Test facility at DESY, location Zeuthen (PITZ). In this contribution the fabrication and first experimental tests towards a Lithium plasma cell are highlighted. The distinctive feature of this plasma cell is the addition of side ports for insertion of the ionization laser beam and for diagnostics purposes., Proceedings of the 5th Int. Particle Accelerator Conf., IPAC2014, Dresden, Germany

Recently three RF guns were prepared at the Photo Injector Test Facility at DESY, location Zeuthen (PITZ) for their subsequent operation at FLASH and the European XFEL. The gun 3.1 is a previous cavity design and is currently installed and operated at FLASH, the other two guns 4.3 and 4.4 were of the current cavity design and are dedicated to serve for the start-up of the European XFEL photo-injector. All three cavities had been dry-ice-cleaned prior their conditioning and hence showed low dark current levels. The lowest dark current level – as low as 60μA at 65MV/m field amplitude – has been observed for the gun 3.1. This paper reports in details about the conditioning process of the most recent gun 4.4. It informs about experience gained at PITZ during establishing of the RF conditioning procedure and provides a comparison with the other gun cavities in terms of the dark currents. It also summarizes the major setup upgrades, which have affected the conditioning processes of the cavities., Proceedings of the 5th Int. Particle Accelerator Conf., IPAC2014, Dresden, Germany

The Photo Injector Test facility at DESY, Zeuthen site (PITZ), focuses on testing, characterizing and optimizing high brightness electron sources for free electron lasers. PITZ is equipped with a number of transverse emittance measurement stations, among which is the Phase Space Tomography (PST) module. A PST measurement requires a specific transport along the tomography lattice, which ideally rotates the beam in the normalized transverse phase space by 180 degrees in equidistant steps. A preceding matching section is used to provide an injection scheme that delivers the necessary beam parameters for the design transport along the tomography lattice. The high charge density and moderate energy of the electron bunch at PITZ contribute to significant space-charge forces which lead to emittance growth and consequent mismatches of the design parameters. This article presents and evaluates measurements of the emittance increase along the matching section of a 1 nC beam at 22 MeV/c under different focusing schemes., Proceedings of the 5th Int. Particle Accelerator Conf., IPAC2014, Dresden, Germany

3rd European Advanced Accelerator Concepts Workshop, EAAC 2017, La Biodola, Isola d'Elba, Italy, 24 Sep 2017 - 30 Sep 2017; Nuclear instruments & methods in physics research / A 909, 177 - 180 (2018). doi:10.1016/j.nima.2018.04.008, The AXSIS project (Attosecond X-ray Science: Imaging and Spectroscopy) aims to develop a THz-driven compact X-ray source for applications e.g. in chemistry and biology by using ultrafast coherent diffraction imaging and spectroscopy. The key components of AXSIS are the THz-driven electron gun and THz-driven dielectric loaded linear accelerator as well as an inverse Compton scattering scheme for the X-rays production.This paper is focused on the prototype of the THz-driven electron gun which is capable of accelerating electrons up to tens of keV. Such a gun was manufactured and tested at the test-stand at DESY. Due to variations in gun fabrication and generation of THz-fields the gun is not exactly operated at design parameters. Extended simulations have been performed to understand the experimentally observed performance of the gun. A detailed comparison between simulations and experimental measurements is presented in this paper., Published by Elsevier, Amsterdam