Status and operation of the Linac4 ion source prototypes

J Lettry; D Aguglia; P Andersson; S Bertolo; A Butterworth; Y Coutron; A Dallocchio; E Chaudet; J Gil-Flores; R Guida; J Hansen; A Hatayama; I Koszar; E Mahner; C Mastrostefano; S Mathot; S Mattei; Ø Midttun; P Moyret; D Nisbet; K Nishida; M O'Neil; M Ohta; M Paoluzzi; C Pasquino; H Pereira; J Rochez; J Sanchez Alvarez; J Sanchez Arias; R Scrivens; T Shibata; D Steyaert; N Thaus; T Yamamoto

doi:10.1063/1.4848975

Status and operation of the Linac4 ion source prototypes

Rev Sci Instrum. 2014 Feb;85(2):02B122. doi: 10.1063/1.4848975.

Authors

J Lettry¹, D Aguglia¹, P Andersson¹, S Bertolo¹, A Butterworth¹, Y Coutron¹, A Dallocchio¹, E Chaudet¹, J Gil-Flores¹, R Guida¹, J Hansen¹, A Hatayama², I Koszar¹, E Mahner¹, C Mastrostefano¹, S Mathot¹, S Mattei¹, Ø Midttun¹, P Moyret¹, D Nisbet¹, K Nishida², M O'Neil¹, M Ohta², M Paoluzzi¹, C Pasquino¹, H Pereira¹, J Rochez¹, J Sanchez Alvarez¹, J Sanchez Arias¹, R Scrivens¹, T Shibata², D Steyaert¹, N Thaus¹, T Yamamoto²

Affiliations

¹ CERN, 1211 Geneva 23, Switzerland.
² Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.

PMID: 24593562
DOI: 10.1063/1.4848975

Abstract

CERN's Linac4 45 kV H(-) ion sources prototypes are installed at a dedicated ion source test stand and in the Linac4 tunnel. The operation of the pulsed hydrogen injection, RF sustained plasma, and pulsed high voltages are described. The first experimental results of two prototypes relying on 2 MHz RF-plasma heating are presented. The plasma is ignited via capacitive coupling, and sustained by inductive coupling. The light emitted from the plasma is collected by viewports pointing to the plasma chamber wall in the middle of the RF solenoid and to the plasma chamber axis. Preliminary measurements of optical emission spectroscopy and photometry of the plasma have been performed. The design of a cesiated ion source is presented. The volume source has produced a 45 keV H(-) beam of 16-22 mA which has successfully been used for the commissioning of the Low Energy Beam Transport (LEBT), Radio Frequency Quadrupole (RFQ) accelerator, and chopper of Linac4.