IPAC2011 - List of Authors (Gonzalez, O.)

Paper	Title	Page
MOPC043	Electromagnetic Simulations of the Input Power Couplers for the ESS-Bilbao RFQ	172
	O. Gonzalez, I. Bustinduy, N. Garmendia, J.L. Munoz, A. Velez ESS Bilbao, Bilbao, Spain F.J. Bermejo Bilbao, Faculty of Science and Technology, Bilbao, Spain V. Etxebarria, J. Portilla University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
	An input power system is currently being designed at ESS-Bilbao in order to inject the RF power provided by a klystron into the RFQ as part of the linac. In this work, some input power couplers based on a coaxial topology are carefully studied from an electromagnetic point of view. As we will show, the electrical properties of the ceramic window used to ensure the vacuum of the RFQ crucially deteriorates the matching of the devices. To overcome this drawback, a full-wave electromagnetic simulator is used to optimize the coupler dimensions in order to minimize both the return and insertion losses.

MOPC044	Design of the Radiofrequency Quadrupole Coldmodel for the ESS-BILBAO Linear Accelerator	175
	A. Velez, I. Bustinduy, N. Garmendia, O. Gonzalez, J.L. Munoz, D. de Cos ESS Bilbao, Bilbao, Spain F.J. Bermejo Bilbao, Faculty of Science and Technology, Bilbao, Spain V. Etxebarria, J. Portilla University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
	This work will present the design of the ESS-Bilbao LINAC RFQ cold model. The process goes through the electromagnetic design of the cavity by properly setting the resonant quadrupole and dipole modes, as well as the resonance frequency. The prototype includes the vane modulation designed to accelerate a 75 mA proton beam from 75 keV to 3 MeV, with an operating frequency of 352.2 MHz. To this end, electromagnetic and electrostatic simulations have been performed by means of the commercial software COMSOL. Furthemore, results for the three components of the electrical field distribution will be presented and compared to those calculated by evaluating the 8-term multipole expansion.

THPS023	Automatic Tuner Unit Design, Simulation and Measurement for Automatic Operation of the RF System in the ESS-Bilbao H⁺ Ion Source	3469
	L. Muguira, I. Arredondo, D. Belver, M. Eguiraun, F.J. Fernandez Huerta, J. Feuchtwanger, N. Garmendia, O. Gonzalez, J. Verdu ESS-Bilbao, Zamudio, Spain V. Etxebarria, J. Jugo, J. Portilla University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
	Funding: The present work is supported by the Basque Government and Spanish Ministry of Science and Innovation. The Ion Source responsible intended to generate a high current and low emittance proton beam for the ESS-Bilbao is currently under construction. The plasma in the source is generated by coupling the 2.72 GHz power input from a Klystron through a magnetic field with an intensity close to the electron cyclotron resonance (ECR) field at the input RF frequency. The electrical behavior of the plasma strongly depends on different plasma characteristics which, at the same time, also depend on the microwave absorption. Thus, in order to maximize the RF power transferred to the plasma, a waveguide automatic tuner unit is employed to match the generator output to the electric impedance of the plasma. This device is generally adjusted manually. In this paper, the design, the 1D and 3D simulation, and measurements are presented which allows us to propose an automatic and real time control of the device. In a first approximation, with the aim of testing the proper operation of the automatic tuner unit, an in-house variable phase shifter and attenuator has been designed and manufactured to simulate the electric behavior of the plasma.

Paper

Title

Page

Electromagnetic Simulations of the Input Power Couplers for the ESS-Bilbao RFQ

172

O. Gonzalez, I. Bustinduy, N. Garmendia, J.L. Munoz, A. Velez
ESS Bilbao, Bilbao, Spain
F.J. Bermejo
Bilbao, Faculty of Science and Technology, Bilbao, Spain
V. Etxebarria, J. Portilla
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain

An input power system is currently being designed at ESS-Bilbao in order to inject the RF power provided by a klystron into the RFQ as part of the linac. In this work, some input power couplers based on a coaxial topology are carefully studied from an electromagnetic point of view. As we will show, the electrical properties of the ceramic window used to ensure the vacuum of the RFQ crucially deteriorates the matching of the devices. To overcome this drawback, a full-wave electromagnetic simulator is used to optimize the coupler dimensions in order to minimize both the return and insertion losses.

MOPC044

Design of the Radiofrequency Quadrupole Coldmodel for the ESS-BILBAO Linear Accelerator

175

A. Velez, I. Bustinduy, N. Garmendia, O. Gonzalez, J.L. Munoz, D. de Cos
ESS Bilbao, Bilbao, Spain
F.J. Bermejo
Bilbao, Faculty of Science and Technology, Bilbao, Spain
V. Etxebarria, J. Portilla
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain

This work will present the design of the ESS-Bilbao LINAC RFQ cold model. The process goes through the electromagnetic design of the cavity by properly setting the resonant quadrupole and dipole modes, as well as the resonance frequency. The prototype includes the vane modulation designed to accelerate a 75 mA proton beam from 75 keV to 3 MeV, with an operating frequency of 352.2 MHz. To this end, electromagnetic and electrostatic simulations have been performed by means of the commercial software COMSOL. Furthemore, results for the three components of the electrical field distribution will be presented and compared to those calculated by evaluating the 8-term multipole expansion.

THPS023

Automatic Tuner Unit Design, Simulation and Measurement for Automatic Operation of the RF System in the ESS-Bilbao H⁺ Ion Source

3469

L. Muguira, I. Arredondo, D. Belver, M. Eguiraun, F.J. Fernandez Huerta, J. Feuchtwanger, N. Garmendia, O. Gonzalez, J. Verdu
ESS-Bilbao, Zamudio, Spain
V. Etxebarria, J. Jugo, J. Portilla
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain

Funding: The present work is supported by the Basque Government and Spanish Ministry of Science and Innovation.
The Ion Source responsible intended to generate a high current and low emittance proton beam for the ESS-Bilbao is currently under construction. The plasma in the source is generated by coupling the 2.72 GHz power input from a Klystron through a magnetic field with an intensity close to the electron cyclotron resonance (ECR) field at the input RF frequency. The electrical behavior of the plasma strongly depends on different plasma characteristics which, at the same time, also depend on the microwave absorption. Thus, in order to maximize the RF power transferred to the plasma, a waveguide automatic tuner unit is employed to match the generator output to the electric impedance of the plasma. This device is generally adjusted manually. In this paper, the design, the 1D and 3D simulation, and measurements are presented which allows us to propose an automatic and real time control of the device. In a first approximation, with the aim of testing the proper operation of the automatic tuner unit, an in-house variable phase shifter and attenuator has been designed and manufactured to simulate the electric behavior of the plasma.