SRF2013 - List of Authors (Pagani, C.)

Paper	Title	Page
MOP011	European XFEL 3.9 GHz System	100
	P. Pierini, M. Bertucci, A. Bosotti, C. Maiano, P. Michelato, L. Monaco, R. Paparella, D. Sertore INFN/LASA, Segrate (MI), Italy C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy E. Vogel DESY, Hamburg, Germany
	The third harmonic system of the European XFEL is a joint INFN and DESY contribution to the project. Achievements, status and activity plan will be reviewed.

TUP035	Neutron Activation Analysis as a Foreign Intrusion Cavity DetectionTool	495
	C. Maiano, P. Michelato INFN/LASA, Segrate (MI), Italy M. Clemenza Universita Milano Bicocca, MILANO, Italy C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy
	Neutron Activation Analysis (NAA) is one of the currently available techniques used to determine contaminants in Nb superconducting cavities, allowing a non-destructive determination of foreign materials, provided they have radioactive isotopes with a sufficiently long half-life. We present the NAA technique application with the goal of contaminants determination, identification and localization for the European XFEL 3rd harmonic cavities (3.9 GHz). Irradiation and analysis has been performed in collaboration with the LENA nuclear reactor (Pavia, Italy) and the University of Milano Bicocca. The main difference respect to the measurements performed in the past is the goal to apply of the NNA directly to entire cavities and not to material samples. Currently nine samples were exposed to thermal and fast neutron flux and the resulting activity was measured with HPGe detectors.

TUP062	Application of In-Vacuum Infrared Pyrometry During Fabrication of European XFEL Niobium Cavities	570
	L. Monaco, P. Michelato, D. Sertore INFN/LASA, Segrate (MI), Italy V. Battista, G. Corniani, M. Festa Ettore Zanon S.p.A., Schio, Italy C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy
	A technique to measure the temperature of Niobium components in vacuum during Electron Beam Welding (EBW) operation is presented and results obtained on the large scale cavity production for the European XFEL are discussed. During the EBW process, the knowledge of the components temperature during the welding operation could help both for the better choice of the welding parameters and for the optimization of the production cycle. In collaboration with the Italian firm Ettore Zanon (EZ), we developed a system able to measure the temperature of Nb components in vacuum during EBW operation using a IR pyrometer placed outside the vacuum chamber through an appropriate vacuum viewport. In the paper the experience of this device during the production of Nb components for the XFEL 1.3 GHz cavity production is discussed.

TUP102	Quench Detection Diagnostics on 3.9 GHz XFEL Cavities	710
	M. Bertucci, A. Bosotti, L. Garolfi, P. Michelato, L. Monaco, D. Sertore INFN/LASA, Segrate (MI), Italy C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy
	This paper presents results of quench localization on 3.9 GHz XFEL prototype cavities tested at LASA vertical test facility. Cavities have been equipped with OST second sound detectors and thermometry sensors. A first guess for quench position has been obtained from modal analysis. Second sound sensors confirmed the quench position resolving also the symmetry degeneracy given by the RF mode pattern analysis. In a subsequent vertical test, second sound and temperature sensors have been installed nearby the suspect quench position. From Thermometry mapping, a sudden increase in cavity temperature within a small region is evident, therefore confirming that a local thermal breakdown due to defect heating occurs in the predicted quench point. The quench region deduced with the mentioned techniques is eventually compared with results of optical inspection.

TUP110	An X-Ray Fluorescence Probe for Defect Detection in Superconducting 1.3 GHz Cavities	736
	P. Michelato, M. Bertucci INFN/LASA, Segrate (MI), Italy A. Navitski, W. Singer, X. Singer DESY, Hamburg, Germany C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy Y. Tamashevich Uni HH, Hamburg, Germany
	The aim of this project is to develop a system for defect detection by means of X-ray fluorescence (XRF) analysis. XRF is a high sensitivity spectroscopy technique allowing the detection of trace element content, such as the few microgram impurities, responsible for low cavity performances if embedded in the equatorial region during cavity manufacturing. The proposed setup is customized on 1.3 GHz TESLA-type niobium cavities: both the detector and the X-ray excitation source are miniaturized so to allow the probe to enter within the 70 mm iris diameter and aside of the HOM couplers. The detection-excitation geometry is focused on cavity cell equator surface located at about 10³ mm from the cavity axis, with an intrinsic spot-size of about 10 mm. The measuring head will be settled on a high angular resolution optical inspection system at DESY, exploiting the experience of OBACHT. Defect position is obtained by means of angular inner cavity surface scanning. A quantitative determination of defect content can also be carried out by means of fundamental parameters technique with a Niobium standard calibration.

THP077	Coaxial Blade Tuner for European XFEL 3.9 GHz cavities	1101
	R. Paparella, M. Bertucci, A. Bosotti INFN/LASA, Segrate (MI), Italy C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy
	The European XFEL linac injector features a third harmonic section jointly realized by INFN and DESY and hosting a 3.9 GHz 9-cell cavities cryomodule. The cold tuning system, developed by INFN for these cavities, is inspired by the coaxial Blade Tuner already qualified for ILC cavities. Design, fabrication and room temperature qualification of first tuner units produced are reviewed in this paper.

Paper

Title

Page

European XFEL 3.9 GHz System

100

P. Pierini, M. Bertucci, A. Bosotti, C. Maiano, P. Michelato, L. Monaco, R. Paparella, D. Sertore
INFN/LASA, Segrate (MI), Italy
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy
E. Vogel
DESY, Hamburg, Germany

The third harmonic system of the European XFEL is a joint INFN and DESY contribution to the project. Achievements, status and activity plan will be reviewed.

TUP035

Neutron Activation Analysis as a Foreign Intrusion Cavity DetectionTool

495

C. Maiano, P. Michelato
INFN/LASA, Segrate (MI), Italy
M. Clemenza
Universita Milano Bicocca, MILANO, Italy
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy

Neutron Activation Analysis (NAA) is one of the currently available techniques used to determine contaminants in Nb superconducting cavities, allowing a non-destructive determination of foreign materials, provided they have radioactive isotopes with a sufficiently long half-life. We present the NAA technique application with the goal of contaminants determination, identification and localization for the European XFEL 3rd harmonic cavities (3.9 GHz). Irradiation and analysis has been performed in collaboration with the LENA nuclear reactor (Pavia, Italy) and the University of Milano Bicocca. The main difference respect to the measurements performed in the past is the goal to apply of the NNA directly to entire cavities and not to material samples. Currently nine samples were exposed to thermal and fast neutron flux and the resulting activity was measured with HPGe detectors.

TUP062

Application of In-Vacuum Infrared Pyrometry During Fabrication of European XFEL Niobium Cavities

570

L. Monaco, P. Michelato, D. Sertore
INFN/LASA, Segrate (MI), Italy
V. Battista, G. Corniani, M. Festa
Ettore Zanon S.p.A., Schio, Italy
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy

A technique to measure the temperature of Niobium components in vacuum during Electron Beam Welding (EBW) operation is presented and results obtained on the large scale cavity production for the European XFEL are discussed. During the EBW process, the knowledge of the components temperature during the welding operation could help both for the better choice of the welding parameters and for the optimization of the production cycle. In collaboration with the Italian firm Ettore Zanon (EZ), we developed a system able to measure the temperature of Nb components in vacuum during EBW operation using a IR pyrometer placed outside the vacuum chamber through an appropriate vacuum viewport. In the paper the experience of this device during the production of Nb components for the XFEL 1.3 GHz cavity production is discussed.

TUP102

Quench Detection Diagnostics on 3.9 GHz XFEL Cavities

710

M. Bertucci, A. Bosotti, L. Garolfi, P. Michelato, L. Monaco, D. Sertore
INFN/LASA, Segrate (MI), Italy
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy

This paper presents results of quench localization on 3.9 GHz XFEL prototype cavities tested at LASA vertical test facility. Cavities have been equipped with OST second sound detectors and thermometry sensors. A first guess for quench position has been obtained from modal analysis. Second sound sensors confirmed the quench position resolving also the symmetry degeneracy given by the RF mode pattern analysis. In a subsequent vertical test, second sound and temperature sensors have been installed nearby the suspect quench position. From Thermometry mapping, a sudden increase in cavity temperature within a small region is evident, therefore confirming that a local thermal breakdown due to defect heating occurs in the predicted quench point. The quench region deduced with the mentioned techniques is eventually compared with results of optical inspection.

TUP110

An X-Ray Fluorescence Probe for Defect Detection in Superconducting 1.3 GHz Cavities

736

P. Michelato, M. Bertucci
INFN/LASA, Segrate (MI), Italy
A. Navitski, W. Singer, X. Singer
DESY, Hamburg, Germany
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy
Y. Tamashevich
Uni HH, Hamburg, Germany

The aim of this project is to develop a system for defect detection by means of X-ray fluorescence (XRF) analysis. XRF is a high sensitivity spectroscopy technique allowing the detection of trace element content, such as the few microgram impurities, responsible for low cavity performances if embedded in the equatorial region during cavity manufacturing. The proposed setup is customized on 1.3 GHz TESLA-type niobium cavities: both the detector and the X-ray excitation source are miniaturized so to allow the probe to enter within the 70 mm iris diameter and aside of the HOM couplers. The detection-excitation geometry is focused on cavity cell equator surface located at about 10³ mm from the cavity axis, with an intrinsic spot-size of about 10 mm. The measuring head will be settled on a high angular resolution optical inspection system at DESY, exploiting the experience of OBACHT. Defect position is obtained by means of angular inner cavity surface scanning. A quantitative determination of defect content can also be carried out by means of fundamental parameters technique with a Niobium standard calibration.

THP077

Coaxial Blade Tuner for European XFEL 3.9 GHz cavities

1101

R. Paparella, M. Bertucci, A. Bosotti
INFN/LASA, Segrate (MI), Italy
C. Pagani
Università degli Studi di Milano & INFN, Segrate, Italy

The European XFEL linac injector features a third harmonic section jointly realized by INFN and DESY and hosting a 3.9 GHz 9-cell cavities cryomodule. The cold tuning system, developed by INFN for these cavities, is inspired by the coaxial Blade Tuner already qualified for ILC cavities. Design, fabrication and room temperature qualification of first tuner units produced are reviewed in this paper.