IPAC2011 - List of Authors (Munoz, J.L.)

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.

WEPC023	Beam Dynamics Simulations for the ESS-Bilbao H⁻ Ion Source	2052
	I. Bustinduy, F.J. Bermejo, D. Fernandez-Cañoto, J.L. Munoz, I. Rodríguez ESS Bilbao, Bilbao, Spain M. Eguiraun, J. Feuchtwanger, Z. Izaola ESS-Bilbao, Zamudio, Spain
	Simulations are performed for the Ion Source Test Stand (ITUR) of the ESS-Bilbao research accelerator facility. The beam dynamics is investigated as a function of the extraction voltages, the ion current, and the inclination angle of the ion source. The ITUR Penning H− ion source has the plasma aperture plate and extraction electrode inclined a certain angle with respect to the vertical axis to compensate for the Penning magnets field. The negative charged particles are extracted through a rectangular slit of 10×6 mm2. The extraction system is mainly composed of two devices, a rectangular extraction electrode and a refrigerated trumpet shaped device acting as an Einzel lens to focus the beam, and also, as a trap for neutral cesium atoms exiting from the source. Results are calculated and analyzed at the DC Current Transformer and pepperpot positions located at 245 mm and 882 mm from the ion source.

WEPO012	Calculation, Design and Manufacturing of a Resistive Quadrupole for the ESS-Bilbao Transfer Lines	2418
	I. Rodríguez, F.J. Bermejo, J.L. Munoz, D. de Cos ESS Bilbao, Bilbao, Spain
	The first stage of the ESS-Bilbao LINAC will accelerate H⁺ and H− high current beams up to 50 MeV for different applications. After the last acceleration step in the DTL, the beam will either be transported to the experimental laboratories by the means of several transfer lines, or continue to a further acceleration step in spoke cavities. The first design of one of the quadrupoles that focus the beam along the transfer lines is presented. The quadrupoles will have an aperture of 63 mm and 20 T/m maximum gradient, featuring a short iron yoke of 100 mm. All the quadrupoles of the transfer lines are expected to be similar in order to simplify the design and manufacturing processes. The iron yoke is small and highly saturated, and an optimization of the 3D harmonics in the load-line is developed to fulfil the field quality specifications. The required current density is high (about 8.2 A/mm2), therefore a water cooled hollow conductor is used to cool down the coils. The cooling and power supply requirements are calculated in this paper. The most important manufacturing indications are also presented.

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.

WEPC023

Beam Dynamics Simulations for the ESS-Bilbao H⁻ Ion Source

2052

I. Bustinduy, F.J. Bermejo, D. Fernandez-Cañoto, J.L. Munoz, I. Rodríguez
ESS Bilbao, Bilbao, Spain
M. Eguiraun, J. Feuchtwanger, Z. Izaola
ESS-Bilbao, Zamudio, Spain

Simulations are performed for the Ion Source Test Stand (ITUR) of the ESS-Bilbao research accelerator facility. The beam dynamics is investigated as a function of the extraction voltages, the ion current, and the inclination angle of the ion source. The ITUR Penning H− ion source has the plasma aperture plate and extraction electrode inclined a certain angle with respect to the vertical axis to compensate for the Penning magnets field. The negative charged particles are extracted through a rectangular slit of 10×6 mm2. The extraction system is mainly composed of two devices, a rectangular extraction electrode and a refrigerated trumpet shaped device acting as an Einzel lens to focus the beam, and also, as a trap for neutral cesium atoms exiting from the source. Results are calculated and analyzed at the DC Current Transformer and pepperpot positions located at 245 mm and 882 mm from the ion source.

WEPO012

Calculation, Design and Manufacturing of a Resistive Quadrupole for the ESS-Bilbao Transfer Lines

2418

I. Rodríguez, F.J. Bermejo, J.L. Munoz, D. de Cos
ESS Bilbao, Bilbao, Spain

The first stage of the ESS-Bilbao LINAC will accelerate H⁺ and H− high current beams up to 50 MeV for different applications. After the last acceleration step in the DTL, the beam will either be transported to the experimental laboratories by the means of several transfer lines, or continue to a further acceleration step in spoke cavities. The first design of one of the quadrupoles that focus the beam along the transfer lines is presented. The quadrupoles will have an aperture of 63 mm and 20 T/m maximum gradient, featuring a short iron yoke of 100 mm. All the quadrupoles of the transfer lines are expected to be similar in order to simplify the design and manufacturing processes. The iron yoke is small and highly saturated, and an optimization of the 3D harmonics in the load-line is developed to fulfil the field quality specifications. The required current density is high (about 8.2 A/mm2), therefore a water cooled hollow conductor is used to cool down the coils. The cooling and power supply requirements are calculated in this paper. The most important manufacturing indications are also presented.