31 research outputs found
Production of long bunch trains with 4.5muC total charge using a photoinjector
No full textA photoinjector, PHIN (PHotoINjector), has been realized at CERN by a joint effort of several institutes within the European Coordinated Accelerator Research in Europe program. The test facility has been installed and commissioned at CERN with the aim to demonstrate the beam parameters needed for the CLIC Test Facility 3 (CTF3). This beam is unique with respect to its long bunch train and high average charge per bunch requirements. The nominal beam for CTF3 consists of 1908 bunches each having a 2.33 nC charge and a bunch frequency of 1.5 GHz. Thus, a total charge of ∼4.4 μC has to be extracted and accelerated. The stability of the intensity and the beam parameters along this exceptionally high average current train is crucial for the correct functioning of the CLIC drive beam scheme. Consequently, extensive time-resolved measurements of the transverse and longitudinal beam parameters have been developed, optimized, and performed. The shot-to-shot intensity stability has been studied in detail for the electron and the laser beams, simultaneously. The PHIN photoinjector has been commissioned between 2008 and 2010 during intermittent operations. This paper reports on the obtained results in order to demonstrate the feasibility and the stability of the required beam parameters
The AWAKE Run 2 programme and beyond
No full textAutores: Edda Gschwendtner, Konstantin Lotov, Patric Muggli, Matthew Wing, Riccardo Agnello, Claudia Christina Ahdida, Maria Carolina Amoedo Goncalves, Yanis Andrebe, Oznur Apsimon, Robert Apsimon, Jordan Matias Arnesano, Anna-Maria Bachmann, Diego Barrientos, Fabian Batsch, Vittorio Bencini, Michele Bergamaschi, Patrick Blanchard, Philip Nicholas Burrows, Birger Buttenschön, Allen Caldwell, James Chappell, Eric Chevallay, Moses Chung, David Andrew Cooke, Heiko Damerau, Can Davut, Gabor Demeter, Amos Christopher Dexter, Steffen Doebert, Francesa Ann Elverson, John Farmer, Ambrogio Fasoli, Valentin Fedosseev, Ricardo Fonseca, Ivo Furno, Spencer Gessner, Aleksandr Gorn, Eduardo Granados, Marcel Granetzny, Tim Graubner, Olaf Grulke, Eloise Daria Guran, Vasyl Hafych, Anthony Hartin, James Henderson, Mathias Hüther, Miklos Kedves, Fearghus Keeble, Vadim Khudiakov, Seong-Yeol Kim, Florian Kraus, Michel Krupa, Thibaut Lefevre, Linbo Liang, Shengli Liu, Nelson Lopes, Miguel Martinez Calderon, Stefano Mazzoni, David Medina Godoy, Joshua Moody, Kookjin Moon, Pablo Israel Morales Guzmán, Mariana Moreira, Tatiana Nechaeva, Elzbieta Nowak, Collette Pakuza, Harsha Panuganti, Ans Pardons, Kevin Pepitone, Aravinda Perera, Jan Pucek, Alexander Pukhov, Rebecca Louise Ramjiawan, Stephane Rey, Adam Scaachi, Oliver Schmitz, Eugenio Senes, Fernando Silva, Luis Silva, Christine Stollberg, Alban Sublet, Catherine Swain, Athanasios Topaloudis, Nuno Torrado, Petr Tuev, Marlene Turner, Francesco Velotti, Livio Verra, Victor Verzilov, Jorge Vieira, Helmut Vincke, Martin Weidl, Carsten Welsch, Manfred Wendt, Peerawan Wiwattananon, Joseph Wolfenden, Benjamin Woolley, Samuel Wyler, Guoxing Xia, Vlada Yarygova, Michael Zepp, Giovanni Zevi Della Porta. ::: Publisher: [MDPI] ::: Location: [
Challenges of Automating the Photocathode Fabrication Process at CERN
No full textThe CERN Photoemission Laboratory was founded in 1989 with the goal of studying laser-driven electron sources, for producing high-brightness electron beams within the framework of the Compact Linear Collider (CLIC) study. To produce these photocathodes, two processes run in parallel. The first process, which is slow and asynchronous, controls and monitors the evaporation of photoemissive material. For this first step several power supplies are controlled to evaporate different metals through the Joule effect, with the power maintained constant in time and the thickness deposited monitored. The second process is synchronized with a laser trigger ranging from 0.1 to 50Hz, where the photocurrent and laser energy are measured to calculate the Quantum Efficiency. The control system for these processes has recently been renovated to benefit from the modularity of a PXI-based real-time environment using the standard CERN MiddleWare communication layer (CMW). This paper describes the challenges of the fabrication process as well as the flexibility introduced by using a PXI system
Capabilities and performance of the CLEAR facility photo-injector
No full textThis paper describes the current functionality and newly implemented capabilities of the CLEAR facility photo-injector laser. The primary focus for CLEAR is general R&D and component studies for existing and future machines at CERN. Accordingly, its photo-injector laser system has been upgraded in order to accommodate for a large range of experimental setups and tests. The systems and performance presented here have been developed with a view on improving the CLEAR injector flexibility, reliability and its systematic optimization
Production of Mass-Separated Erbium-169 Towards the First Preclinical in vitro Investigations
No full textThe β−-particle-emitting erbium-169 is a potential radionuclide toward therapy of metastasized cancer diseases. It can be produced in nuclear research reactors, irradiating isotopically-enriched 168Er2O3. This path, however, is not suitable for receptor-targeted radionuclide therapy, where high specific molar activities are required. In this study, an electromagnetic isotope separation technique was applied after neutron irradiation to boost the specific activity by separating 169Er from 168Er targets. The separation efficiency increased up to 0.5% using resonant laser ionization. A subsequent chemical purification process was developed as well as activity standardization of the radionuclidically pure 169Er. The quality of the 169Er product permitted radiolabeling and pre-clinical studies. A preliminary in vitro experiment was accomplished, using a 169Er-PSMA-617, to show the potential of 169Er to reduce tumor cell viability. © Copyright © 2021 Talip, Borgna, Müller, Ulrich, Duchemin, Ramos, Stora, Köster, Nedjadi, Gadelshin, Fedosseev, Juget, Bailat, Fankhauser, Wilkins, Lambert, Marsh, Fedorov, Chevallay, Fernier, Schibli and van der Meulen.The authors thank CERN ISOLDE and RILIS teams for the laser operation (Maxim D. Seliverstov, Katerina Chrysalidis), radiation protection and logistic teams of PSI (Tobias Schneider) and CERN (Alexandre Dorsival, Matthieu Deschamps and Elodie Aubert, Philippe Bertreix, Nicolas Riggaz, Nabil Menaa, Aurore Boscher, Jeremie Comte, Benjamin Juif); the LARISSA workgroup of Mainz University for the laser preparation and erbium laser ionization scheme development (Prof. Dr. Klaus Wendt and Dr. Dominik Studer). The authors are grateful to Fan Sozzi-Guo, Muhamet Djelili, Alexander V?gele and Walter Hirzel (PSI) and Bernard Cr?pieux, Giacomo Lunghi, Francesco Riccardi, Miranda Van Stenis, Thomas Schneider (CERN) for technical support. Funding. ZT and NM received funding from the Swiss National Science Foundation (SNF Grant Number: 200021_188495). CM obtained funding for this project from the Swiss Cancer Research (KFS-4678-02-2019-R). FB received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sk?odowska-Curie Grant Agreement No 701647
X-ray Photoemission Spectroscopy Studies of Cesium Antimonide Photocathodes for Photoinjector Applications
No full textWithin the CLIC (Compact Linear Collider) project, feasibility studies of a photoinjector option for the drive beam as an alternative to its baseline design using a thermionic electron gun (Geschonke et al. [1] ) are on-going. This R&D; program covers both the laser and the photocathode side. Cesium antimonide cathodes were produced at CERN by co-deposition onto copper substrates and characterized by photoemission and by XPS (X-ray Photoemission Spectroscopy) analysis. A systematic study on newly produced and used photocathodes was conducted in order to correlate the surface composition to the photoemissive properties
Recent Results on the Performance of Cs3Sb Photocathodes in the PHIN RF-Gun
No full textFor the CLIC drive beam a photoinjector option is under study at CERN as an alternative to the thermionic electron gun in the CLIC baseline design. The CLIC drive beam requires a high bunch charge of 8.4 nC and 0.14 ms long trains with 2 ns bunch spacing, which is challenging for a photoinjector. In particular the required long and high intensity laser pulses cause a degradation of the beam quality during the frequency conversion process, which generates the ultra-violet laser beam needed for standard Cs2Te photocathodes. To overcome this issue Cs3Sb cathodes sensitive to green light have been studied at the high-charge PHIN photoinjector since a few years. In this paper recent measurements of fundamental properties of Cs3Sb photocathodes such as quantum efficiency, cathode lifetime and dark current from summer 2014 will be presented, and compared with previous measurements and with the performance of Cs2Te photocathodes
Studies of Cs3Sb cathodes for the CLIC drive beam photo injector option
No full textWithin the CLIC (Compact Linear Collider) project, feasibility studies of a photo injector option for the drive beam as an alternative to its baseline design using a thermionic electron gun are on-going. This R&D program covers both the laser and the photocathode side. Whereas the available laser pulse energy in ultra-violet (UV) is currently limited by the optical defects in the 4thharmonics frequency conversion crystal induced by the0.14 ms long pulse trains, recent measurements of Cs3Sbphotocathodes sensitive to green light showed their potential to overcome this limitation. Moreover, using visible laser beams leads to better stability of produced electron bunches and one can take advantages of the availability of higher quality optics. The studied Cs3Sbphotocathodes have been produced in the CERN photo emission laboratory using the co-deposition technique and tested in a DC gun set-up. The analysis of data acquired during the cathode production process will be presented in this paper, as well as the results of lifetime measurements in the DC gu
Surface Characterization at CERN of Photocathodes for Photoinjector Applications
No full textR&D; on photocathodes takes place at CERN within the CLIC (Compact Linear Collider) project. Photocathodes are produced as thin films on Oxygen Free copper substrate using a co-deposition technique, and characterized in a dedicated laboratory with a DC photo-electron gun. A new UHV carrier vessel compatible with CERN’s XPS (X-ray Photoelectron Spectroscopy) analysis equipment has been commissioned and is used to transport photocathodes from the production laboratory to perform a systematic study of different compounds used as photoemissive materials. In this paper photocathodes used in a RF photoinjector will be characterized and the correlation of their surface properties with their performance will be investigated
Study of the Performance of Cs2Te Cathodes in the PHIN RF Photoinjector using Long Pulse Trains
No full textThe drive beam of CLIC requires unusually high peak and average currents which is challenging for the electron source. As an alternative to the thermionic electron gun foreseen in the baseline design, a photoinjector option is under study at CERN using the PHIN photoinjector, which was designed for a bunch charge of 2.3 nC and 1200 ns train length. During operation with nominal train length in 2014, a large pressure increase in the vacuum system, attributed to a heating of the Faraday cup, caused a degradation of the photocathode. To overcome this problem a vacuum window has been installed to separate the Faraday cup from the rest of the vacuum system. In addition the train length has been further increased to 1600 ns to advance the beam parameters towards CLIC requirements. In this paper recent improved photocathode lifetime measurements carried out under these new conditions will be presented and compared with earlier measurements. Furthermore, the utilized Cs2Te cathode has been analyzed with X-ray Photoelectron Spectroscopy (XPS) before and after its usage in PHIN to get a better understanding of photocathode surface deterioration effects, which will also be discussed
