IPAC2011 - List of Authors (Rathsman, K.)

Paper	Title	Page
MOPC136	The RF Power Source for the High Beta Elliptical Cavities of the ESS Linac	397
	K. Rathsman, H. Danared, R. Zeng ESS, Lund, Sweden A.J. Johansson Lund University, Lund, Sweden C. Lingwood Cockcroft Institute, Lancaster University, Lancaster, United Kingdom R.J.M.Y. Ruber Uppsala University, Uppsala, Sweden C. de Almeida Martins IST-UTL, Lisbon, Portugal
	The European Spallation Source is an intergovernmental project building a multidisciplinary research laboratory based upon the world’s most powerful neutron source. The main facility will be built in Lund, Sweden. Construction is expected to start around 2013 and the first neutrons will be produced in 2019. The ESS linac delivers 5 MW of power to the target at 2.5 GeV, with a nominal current of 50 mA. The 120 high beta elliptical cavities, which operate at a frequency of 704 MHz and accelerate protons from 600 MeV to 2.5 GeV, account for more than half of the total number of rf cavities in the ESS linac and three quarter of the total beam power needed. Because of the large number of rf power sources and the high power level needed, all the design and development efforts for the rf power source have so far been focused on this part of the accelerator. The design and development status of the rf power source is reported in this paper with emphasis on reliability, maintainability, safety, power efficiency, investment cost and production capacity.

TUPS096	ESS Parameter List Database and Web Interface Tools	1762
	K. Rathsman, S. Peggs, P. Reinerfelt, G. Trahern ESS, Lund, Sweden J. Bobnar Cosylab, Ljubljana, Slovenia
	The European Spallation Source is an intergovernmental project building a multidisciplinary research laboratory based upon the world's most powerful neutron source. The main facility will be built in Lund, Sweden. Construction is expected to start around 2013 and the first neutrons will be produced in 2019. The ESS linac delivers 5 MW of power to the target at 2.5 GeV, with a nominal current of 50 mA. The Accelerator Design Update (ADU) collaboration of mainly European institutions will deliver a Technical Design Report at the end of 2012. To ensure consistency of the information being used amongst all subgroups throughout the period of accelerator design and construction, a parameter list database and web interface have been proposed. The main objective is to provide tools to identify inconsistencies among parameters and to enforce groups as well as individuals to work towards the same solution. Another goal is to make the Parameter Lists a live and credible endeavor so that the data and supporting information shall be useful to a wider audience such as external reviewers as well as being easily accessible.

WEPS064	Upgrade Strategies for High Power Proton Linacs	2646
	M. Lindroos, H. Danared, M. Eshraqi, D.P. McGinnis, S. Molloy, S. Peggs, K. Rathsman ESS, Lund, Sweden R.D. Duperrier CEA/DSM/IRFU, France J. Galambos ORNL, Oak Ridge, Tennessee, USA
	High power proton linacs are used as drivers for spallation neutron sources, and are proposed as drivers for sub-critical accelerator driven thorium reactors. A linac optimized for a specific average pulse current can be difficult, or inefficient, to operate at higher currents, for example due to mis-matching between the RF coupler and the beam loaded cavity, and due to Higher Order Mode effects. Hardware is in general designed to meet specific engineering values, such as pulse length and repetition rate, that can be costly and difficult to change, for example due to pre-existing space constraints. We review the different upgrade strategies that are available to proton driver designers, both for linacs under design, such as the European Spallation Source (ESS) in Lund, and also for existing linacs, such as the Spallation Neutron Source (SNS) in Oak Ridge. Potential ESS upgrades towards a beam power higher than 5 MW preserve the original time structure, while the SNS upgrade is directed towards the addition of a second target station.

Paper

Title

Page

The RF Power Source for the High Beta Elliptical Cavities of the ESS Linac

397

K. Rathsman, H. Danared, R. Zeng
ESS, Lund, Sweden
A.J. Johansson
Lund University, Lund, Sweden
C. Lingwood
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
R.J.M.Y. Ruber
Uppsala University, Uppsala, Sweden
C. de Almeida Martins
IST-UTL, Lisbon, Portugal

The European Spallation Source is an intergovernmental project building a multidisciplinary research laboratory based upon the world’s most powerful neutron source. The main facility will be built in Lund, Sweden. Construction is expected to start around 2013 and the first neutrons will be produced in 2019. The ESS linac delivers 5 MW of power to the target at 2.5 GeV, with a nominal current of 50 mA. The 120 high beta elliptical cavities, which operate at a frequency of 704 MHz and accelerate protons from 600 MeV to 2.5 GeV, account for more than half of the total number of rf cavities in the ESS linac and three quarter of the total beam power needed. Because of the large number of rf power sources and the high power level needed, all the design and development efforts for the rf power source have so far been focused on this part of the accelerator. The design and development status of the rf power source is reported in this paper with emphasis on reliability, maintainability, safety, power efficiency, investment cost and production capacity.

TUPS096

ESS Parameter List Database and Web Interface Tools

1762

K. Rathsman, S. Peggs, P. Reinerfelt, G. Trahern
ESS, Lund, Sweden
J. Bobnar
Cosylab, Ljubljana, Slovenia

The European Spallation Source is an intergovernmental project building a multidisciplinary research laboratory based upon the world's most powerful neutron source. The main facility will be built in Lund, Sweden. Construction is expected to start around 2013 and the first neutrons will be produced in 2019. The ESS linac delivers 5 MW of power to the target at 2.5 GeV, with a nominal current of 50 mA. The Accelerator Design Update (ADU) collaboration of mainly European institutions will deliver a Technical Design Report at the end of 2012. To ensure consistency of the information being used amongst all subgroups throughout the period of accelerator design and construction, a parameter list database and web interface have been proposed. The main objective is to provide tools to identify inconsistencies among parameters and to enforce groups as well as individuals to work towards the same solution. Another goal is to make the Parameter Lists a live and credible endeavor so that the data and supporting information shall be useful to a wider audience such as external reviewers as well as being easily accessible.

WEPS064

Upgrade Strategies for High Power Proton Linacs

2646

M. Lindroos, H. Danared, M. Eshraqi, D.P. McGinnis, S. Molloy, S. Peggs, K. Rathsman
ESS, Lund, Sweden
R.D. Duperrier
CEA/DSM/IRFU, France
J. Galambos
ORNL, Oak Ridge, Tennessee, USA

High power proton linacs are used as drivers for spallation neutron sources, and are proposed as drivers for sub-critical accelerator driven thorium reactors. A linac optimized for a specific average pulse current can be difficult, or inefficient, to operate at higher currents, for example due to mis-matching between the RF coupler and the beam loaded cavity, and due to Higher Order Mode effects. Hardware is in general designed to meet specific engineering values, such as pulse length and repetition rate, that can be costly and difficult to change, for example due to pre-existing space constraints. We review the different upgrade strategies that are available to proton driver designers, both for linacs under design, such as the European Spallation Source (ESS) in Lund, and also for existing linacs, such as the Spallation Neutron Source (SNS) in Oak Ridge. Potential ESS upgrades towards a beam power higher than 5 MW preserve the original time structure, while the SNS upgrade is directed towards the addition of a second target station.