IPAC2012 - List of Authors (Etxebarria, V.)

Paper	Title	Page
MOPPR040	Design and Measurements of a Test Stand for the SEM-Grid System of the ESS-BILBAO	867
	D. Belver, J. Feuchtwanger, P.J. González ESS Bilbao, LEIOA, Spain F.J. Bermejo Bilbao, Faculty of Science and Technology, Bilbao, Spain V. Etxebarria, J. Jugo University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
	In the framework of the ESS-Bilbao accelerator, a test stand for the development of Secondary Electron EMission grid (SEM-Grid) has been designed and manufactured as a part of the diagnostics system for beam profile measurements. This test stand is a vacuum system based on an EQ 22/35 electron source from SPECS used as a beam injector. This electron source has an energy range from 0 to 5 KeV and a maximum beam current up to 200 μA. Although we have thought in a SEM-Grid of 40 wires (20 wires in each X and Y direction), two prototypes of 16 wires (8x8) of 250 μm diameter and spaced 1 and 2 mm, respectively, have been developed due to its easier implementation and tested in the test stand. In order to develop an electronics readout system for the SEM-Grid, first studies of the prototype signals have been done. The secondary emission current of each wire will be integrated and amplified to provide a significant voltage signal that can be measured by our acquisition system. A description of the SEM-Grid test stand and the measurements developed is given here.

MOPPR041	Design and Measurements of the Stripline BPM System of the ESS-BILBAO	870
	D. Belver, J. Feuchtwanger, N. Garmendia, P.J. González, L. Muguira, S. Varnasseri ESS Bilbao, LEIOA, Spain F.J. Bermejo Bilbao, Faculty of Science and Technology, Bilbao, Spain V. Etxebarria, J. Jugo, J. Portilla University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
	A new design for the Beam Position Monitors (BPMs) diagnostics of ESS-Bilbao, consisting of a whole block of stripline sensors, has been designed and manufactured. The design is based on travelling wave principles to detect the position of the beam in the vacuum chamber. The length of the stripline is 200 mm and the coverage angle is 0.952 rad. The position of the internal tube simulating the beam can be changed with respect to the outer tube within a range of 20 mm approximately for both X and Y axis, with a resolution less than 10 μm. The characteristics of the block with and without beam are measured and evaluated at frequencies of 175 and 352 MHz, using the electronics system developed for the BPM capacitive pick-ups. This electronics system is divided in an Analog Front-End (AFE) unit, where the signals are conditioned and converted to baseband, and a Digital Unit (DU) to sample them and calculate the position and phase of the beam. In this contribution, the performed tests will be fully described and the results also discussed.

TUPPC030	Status of the Ion Sources at ESS-Bilbao	1227
	J. Feuchtwanger, I. Arredondo, F.J. Bermejo, I. Bustinduy, J. Corres, M. Eguiraun, P.J. González, J.L. Muñoz ESS Bilbao, Bilbao, Spain V. Etxebarria, J. Jugo, J. Portilla University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain R. Miracoli ESS-Bilbao, Zamudio, Spain
	Currently there are two types of ion sources under development and testing at ESS-Bilbao, the first one is a Penning type source based on the ISIS/RAL source, modified to use permanent magnets to generate the Penning field. The second source is an off-resonance ECR source that is being developed in-house. The Penning source is in the late stages of commissioning, and a beam has been extracted from it. Currently the main work on that source is in the optimization of the operating parameters. The ECR source on the other hand is in the early stages of the commissioning, all parts have been fabricated, and Vacuum tests are underway. Testing of the RF and control systems will follow, and finally the whole system will be tested. The control system for both ion sources was developed under LabView, and runs on a real time system. While for testing the timing sequences run locally, the system is being developed so that it can run using a central timing system.

WEPPD070	Automatic Tuner Unit Operation for the Microwave System of the ESS-Bilbao H⁺ Ion Source	2684
	L. Muguira, I. Arredondo, D. Belver, M. Eguiraun, F.J. Fernandez Huerta, J. Feuchtwanger, N. Garmendia, O. González, P.J. González ESS Bilbao, LEIOA, Spain V. Etxebarria, J. Jugo, J. Portilla University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain J. Verdu EPFL, Lausanne, Switzerland
	Funding: The present work is supported by the Basque Government and Spanish Ministry of Science and Innovation. The operation of the waveguide automatic tuner unit (ATU) for optimizing the impedance matching and the RF power coupling in the ESS-Bilbao H⁺ Ion Source (ISHP) is presented. Since the plasma chamber can be considered as a time varying load impedance for the pulsed RF 2.7 GHz high power generator, several approaches have been studied for accurately measuring the load impedance. In the later case, a set of power detectors connected to electric field probes, IQ demodulators and gain/phase detectors connected to dual directional couplers have been integrated. An experimental comparison of these approaches is presented, showing their accuracy, limitations and error-correction methods. Finally, the control system developed for the automatic operation of the triple capacitive post tuner is described, as well as illustrative results.

WEPPR027	Complete Electromagnetic Design of the ESS-Bilbao RFQ Cold Model	2991
	A. Vélez, I. Bustinduy, J. Feuchtwanger, N. Garmendia, O. González, I. Madariaga, J.L. Muñoz, 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
	In this work, the ESS-Bilbao 352,2 Mhz RFQ Cold Model to be built in the ESS-Bilbao accelerator facility is presented. The Cold Model intends to be a small scale representation of the final 4 meters long RFQ which will be able to accelerate a 75 mA proton beam from 75 keV to 3 MeV. The work shown here covers the complete electromagnetic design process of the Cold Model which will be built in aluminium with a total length of 1 meter. Moreover, in order to find out fabrication tolerances, a longitudinal test modulation in the vane regions similar to the one designed for the final RFQ is included in the Cold Model. This modulation represents also a useful tool in order to test the agreement between measurements and electromagnetic simulations. In addition, a complete parametric study of the RFQ ends and radial matchers is presented as an important design parameter able to adjust the field flatness. Finally, slug tuning rods are also added to be able to test the tuning procedures. A final RFQ Cold Model prototype has been designed and is currently under fabrication.

THEPPB001	Design and Fabrication of The ESS-Bilbao RFQ Prototype Models	3228
	I. Bustinduy, F.J. Bermejo, J. Feuchtwanger, N. Garmendia, A. Ghiglino, O. González, P.J. González, I. Madariaga, J.L. Muñoz, I. Rueda, F. Sordo Balbin, A. Vélez, D. de Cos ESS Bilbao, Bilbao, Spain V. Etxebarria, J. Portilla University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain A. Garbayo AVS, Eibar, Gipuzkoa, Spain S. Jolly UCL, London, United Kingdom S.R. Lawrie, A.P. Letchford STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom J.K. Pozimski, P. Savage Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	As part of the development of the ESS-Bilbao Accelerator in Spain, two different sets of radio frequency quadrupole (RFQ) models have been developed. On one hand, a set of four oxygen free high conductivity copper weld test models has been designed and manufactured, in order to test different welding methods as well as other mechanical aspects involved in the fabrication of the RFQ. On the other hand, a 352.2 MHz four vane RFQ cold model, with a length of 1 meter, has been designed and built in Aluminum. It serves as a good test bench to investigate the validity of different finite element analysis (FEA) software packages. This is a critical part, since the design of the final RFQ will be based on such simulations. The cold model also includes 16 slug tuners and 8 couplers/pick-up ports, which will allow to use the bead-pull perturbation method, by measuring the electric ﬁeld profile, Q-value and resonant modes. In order to investigate fabrication tolerances, the cold model also comprises a longitudinal test modulation in the vanes, which is similar to the one designed for the final RFQ.

Paper

Title

Page

Design and Measurements of a Test Stand for the SEM-Grid System of the ESS-BILBAO

867

D. Belver, J. Feuchtwanger, P.J. González
ESS Bilbao, LEIOA, Spain
F.J. Bermejo
Bilbao, Faculty of Science and Technology, Bilbao, Spain
V. Etxebarria, J. Jugo
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain

In the framework of the ESS-Bilbao accelerator, a test stand for the development of Secondary Electron EMission grid (SEM-Grid) has been designed and manufactured as a part of the diagnostics system for beam profile measurements. This test stand is a vacuum system based on an EQ 22/35 electron source from SPECS used as a beam injector. This electron source has an energy range from 0 to 5 KeV and a maximum beam current up to 200 μA. Although we have thought in a SEM-Grid of 40 wires (20 wires in each X and Y direction), two prototypes of 16 wires (8x8) of 250 μm diameter and spaced 1 and 2 mm, respectively, have been developed due to its easier implementation and tested in the test stand. In order to develop an electronics readout system for the SEM-Grid, first studies of the prototype signals have been done. The secondary emission current of each wire will be integrated and amplified to provide a significant voltage signal that can be measured by our acquisition system. A description of the SEM-Grid test stand and the measurements developed is given here.

MOPPR041

Design and Measurements of the Stripline BPM System of the ESS-BILBAO

870

D. Belver, J. Feuchtwanger, N. Garmendia, P.J. González, L. Muguira, S. Varnasseri
ESS Bilbao, LEIOA, Spain
F.J. Bermejo
Bilbao, Faculty of Science and Technology, Bilbao, Spain
V. Etxebarria, J. Jugo, J. Portilla
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain

A new design for the Beam Position Monitors (BPMs) diagnostics of ESS-Bilbao, consisting of a whole block of stripline sensors, has been designed and manufactured. The design is based on travelling wave principles to detect the position of the beam in the vacuum chamber. The length of the stripline is 200 mm and the coverage angle is 0.952 rad. The position of the internal tube simulating the beam can be changed with respect to the outer tube within a range of 20 mm approximately for both X and Y axis, with a resolution less than 10 μm. The characteristics of the block with and without beam are measured and evaluated at frequencies of 175 and 352 MHz, using the electronics system developed for the BPM capacitive pick-ups. This electronics system is divided in an Analog Front-End (AFE) unit, where the signals are conditioned and converted to baseband, and a Digital Unit (DU) to sample them and calculate the position and phase of the beam. In this contribution, the performed tests will be fully described and the results also discussed.

TUPPC030

Status of the Ion Sources at ESS-Bilbao

1227

J. Feuchtwanger, I. Arredondo, F.J. Bermejo, I. Bustinduy, J. Corres, M. Eguiraun, P.J. González, J.L. Muñoz
ESS Bilbao, Bilbao, Spain
V. Etxebarria, J. Jugo, J. Portilla
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
R. Miracoli
ESS-Bilbao, Zamudio, Spain

Currently there are two types of ion sources under development and testing at ESS-Bilbao, the first one is a Penning type source based on the ISIS/RAL source, modified to use permanent magnets to generate the Penning field. The second source is an off-resonance ECR source that is being developed in-house. The Penning source is in the late stages of commissioning, and a beam has been extracted from it. Currently the main work on that source is in the optimization of the operating parameters. The ECR source on the other hand is in the early stages of the commissioning, all parts have been fabricated, and Vacuum tests are underway. Testing of the RF and control systems will follow, and finally the whole system will be tested. The control system for both ion sources was developed under LabView, and runs on a real time system. While for testing the timing sequences run locally, the system is being developed so that it can run using a central timing system.

WEPPD070

Automatic Tuner Unit Operation for the Microwave System of the ESS-Bilbao H⁺ Ion Source

2684

L. Muguira, I. Arredondo, D. Belver, M. Eguiraun, F.J. Fernandez Huerta, J. Feuchtwanger, N. Garmendia, O. González, P.J. González
ESS Bilbao, LEIOA, Spain
V. Etxebarria, J. Jugo, J. Portilla
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
J. Verdu
EPFL, Lausanne, Switzerland

Funding: The present work is supported by the Basque Government and Spanish Ministry of Science and Innovation.
The operation of the waveguide automatic tuner unit (ATU) for optimizing the impedance matching and the RF power coupling in the ESS-Bilbao H⁺ Ion Source (ISHP) is presented. Since the plasma chamber can be considered as a time varying load impedance for the pulsed RF 2.7 GHz high power generator, several approaches have been studied for accurately measuring the load impedance. In the later case, a set of power detectors connected to electric field probes, IQ demodulators and gain/phase detectors connected to dual directional couplers have been integrated. An experimental comparison of these approaches is presented, showing their accuracy, limitations and error-correction methods. Finally, the control system developed for the automatic operation of the triple capacitive post tuner is described, as well as illustrative results.

WEPPR027

Complete Electromagnetic Design of the ESS-Bilbao RFQ Cold Model

2991

A. Vélez, I. Bustinduy, J. Feuchtwanger, N. Garmendia, O. González, I. Madariaga, J.L. Muñoz, 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

In this work, the ESS-Bilbao 352,2 Mhz RFQ Cold Model to be built in the ESS-Bilbao accelerator facility is presented. The Cold Model intends to be a small scale representation of the final 4 meters long RFQ which will be able to accelerate a 75 mA proton beam from 75 keV to 3 MeV. The work shown here covers the complete electromagnetic design process of the Cold Model which will be built in aluminium with a total length of 1 meter. Moreover, in order to find out fabrication tolerances, a longitudinal test modulation in the vane regions similar to the one designed for the final RFQ is included in the Cold Model. This modulation represents also a useful tool in order to test the agreement between measurements and electromagnetic simulations. In addition, a complete parametric study of the RFQ ends and radial matchers is presented as an important design parameter able to adjust the field flatness. Finally, slug tuning rods are also added to be able to test the tuning procedures. A final RFQ Cold Model prototype has been designed and is currently under fabrication.

THEPPB001

Design and Fabrication of The ESS-Bilbao RFQ Prototype Models

3228

I. Bustinduy, F.J. Bermejo, J. Feuchtwanger, N. Garmendia, A. Ghiglino, O. González, P.J. González, I. Madariaga, J.L. Muñoz, I. Rueda, F. Sordo Balbin, A. Vélez, D. de Cos
ESS Bilbao, Bilbao, Spain
V. Etxebarria, J. Portilla
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
A. Garbayo
AVS, Eibar, Gipuzkoa, Spain
S. Jolly
UCL, London, United Kingdom
S.R. Lawrie, A.P. Letchford
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
J.K. Pozimski, P. Savage
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

As part of the development of the ESS-Bilbao Accelerator in Spain, two different sets of radio frequency quadrupole (RFQ) models have been developed. On one hand, a set of four oxygen free high conductivity copper weld test models has been designed and manufactured, in order to test different welding methods as well as other mechanical aspects involved in the fabrication of the RFQ. On the other hand, a 352.2 MHz four vane RFQ cold model, with a length of 1 meter, has been designed and built in Aluminum. It serves as a good test bench to investigate the validity of different finite element analysis (FEA) software packages. This is a critical part, since the design of the final RFQ will be based on such simulations. The cold model also includes 16 slug tuners and 8 couplers/pick-up ports, which will allow to use the bead-pull perturbation method, by measuring the electric ﬁeld profile, Q-value and resonant modes. In order to investigate fabrication tolerances, the cold model also comprises a longitudinal test modulation in the vanes, which is similar to the one designed for the final RFQ.