PERMANENT MAGNET QUADRUPOLE FOR THE 1-ST TANK OF LINAC-4 *

Abstract A rare-earth (REPM) ∅60 mm diameter, 45 mm long quadrupole for the LINAC-4 focusing channel with an integrated gradient of 2.3 T is described. Thin side washers are used for tuning the quad into specified gradient integral with ±0.5 % accuracy. The single washer contribution calculations are discussed. A method for limiting to 30 μm the magnetic axis offset in the REPM quad is discussed to exclude its compensation by the outer diameter machining before inserting into the drift tube. Nonlinearity of the field is less than 1 % in the reference range of 75 % of beam aperture at the central crosssection near the quad axis. The angular quadrupole arrangement in the drift tube will be provided by machining the main groove on the quad surface in the median plane with 1 mrad accuracy. Calculations of the longitudinal gradient distribution between two neighbour quadrupoles showed that some percents should be added to the nominal gradient in the beginning of the LINAC-4 focusing channel because of partial field compensation

SERIES SUPERCONDUCTING CAVITY PRODUCTION FOR THE HIE-ISOLDE PROJECT AT CERN

Abstract In the context of the HIE-ISOLDE linac at CERN, the phase 1 is planned to boost the energy of the machine from 3 MeV/u to 5 MeV/u. For this purpose, it is planned to install 2 cryomodules based on quarter wave resonators (QWRs) made by niobium sputtered on copper. This paper presents the different steps of the cavity series production from the reception from industry to the cavity storage before cryomodule assembly. We will describe the cavity preparation including the resonance frequency measurement, the chemical treatment, the cavity rinsing, the niobium coating and the RF test at 4.5 K