Front End Test Stand - Continuation

Lead Research Organisation: University College London
Department Name: Physics and Astronomy

Abstract

High power proton accelerators (HPPAs) are at the heart of many future large scale scientific facilities such as a spallation-neutron source, Neutrino Factory, high energy physics at the energy or intensity frontier, accelerator driven sub-critical systems, and the transmutation of nuclear waste. Controlling beam-loss induced machine activation during injection into a circular accelerator (synchrotron or FFAG) is essential for safe operation of HPPAs and requires the beam in the injector linac to be chopped very precisely at the synchrotron revolution frequency. The Front End Test Stand (FETS) at RAL has as its primary aim to demonstrate perfect chopping of a high quality, high intensity, negative Hydrogen ion beam at an energy of 3 MeV.
Although primarily a hardware construction project, the FETS collaboration has become an efficient mechanism for sharing the wealth of real-world accelerator expertise within ISIS and the ASTeC Intense Beams Group with the wider academic community as well as benefitting from the specialisations and expertise of the university groups. The work already undertaken has contributed to the UK's continuing international reputation as a centre of excellence and has stimulated collaborations with leading international accelerator institutes such as CERN, FNAL, ESS and CNS.
FETS consists of a high-brightness Penning surface plasma negative-hydrogen-ion source, magnetic Low Energy Beam Transport (LEBT) at 65 keV to match the beam into a 3 MeV Radio Frequency Quadrupole (RFQ) operating at 324 MHz which delivers the 60mA beam to the Medium Energy Beam Transport (MEBT) where the chopping systems are situated. Comprehensive, state-of-the-art diagnostics measure the performance of the system and the beam quality. The ion source, LEBT and high power RF systems have been commissioned and the manufacture of the RFQ is underway.
With this proposal we seek the resources to complete the construction of FETS in a timely manner. This will entail:
The installation, testing and commissioning of the RFQ;
Accelerating the desired beam intensity and beam quality through the RFQ;
The completion of the engineering design and the manufacture of the chopper systems;
The installation, testing and commissioning the MEBT and chopper systems;
The transmission of beam through the MEBT and the demonstration of precise and efficient beam chopping; and
Evaluating the performance of the complete test stand.
In addition, we proposed to evaluate the additional benefits that will accrue from exploiting the FETS as a driver for further developments in proton accelerator systems.

Publications

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Jolly S (2014) Novel integrated design framework for radio frequency quadrupoles in Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

 
Description The Front End Test Stand is a test accelerator for developing high power proton injectors. Injectors are the very front end of a proton linear accelerator, used to accelerate particles from rest up to energies of a few MeV. FETS has a number of novel aspects, including the high beam current (60mA at 10% duty cycle) and fast beam chopper (arbitrary pulse lengths with nanosecond rise times). FETS is an ongoing project, of which UCL is no longer a part, but has demonstrated a completely new method of designing RadioFrequency Quadrupoles. FETS also functions as a test stand for ion source development for the ISIS spallation neutron source: significant progress has been made on the maximum current and pulse duration extracted compared to ISIS, with more than a tenfold increase in average current.
Exploitation Route Facilities that wish to design high power proton accelerators - such as the CERN Linac-4 injector or the European Spallation Neutron Source (ESS) - have already made use of the ion source improvements achieved on FETS. Outside these areas impact is currently limited, since few areas beyond high energy physics research require such intense proton beams.
Sectors Energy,Other

 
Description Improvements to the FETS ion source have fed into improved performance of the ISIS spallation neutron source. ISIS is used by a number of different areas of industry, both in the UK and by visitors from overseas, primarily looking at material structure. Neutron spallation provides a unique insight into the nuclear structure of materials.
First Year Of Impact 2005
Sector Manufacturing, including Industrial Biotechology
Impact Types Economic

 
Description High Power Proton Injectors 
Organisation European Organization for Nuclear Research (CERN)
Department Accelerator Division
Country Switzerland 
Sector Public 
PI Contribution Development of ion sources for high power proton injectors. Development of high current RadioFrequency Quadrupoles. Development of photo detachment laserwire profile measurement diagnostic.
Collaborator Contribution Design of beam position monitoring systems for low-beta beams. Miscellaneous accelerator/diagnostics expertise.
Impact Employment of PASI postdoc (collaboration with FNAL through PASI).
Start Year 2012
 
Description High Power Proton Injectors 
Organisation Fermilab - Fermi National Accelerator Laboratory
Department Project-X
Country United States 
Sector Academic/University 
PI Contribution Development of ion sources for high power proton injectors. Development of high current RadioFrequency Quadrupoles. Development of photo detachment laserwire profile measurement diagnostic.
Collaborator Contribution Design of beam position monitoring systems for low-beta beams. Miscellaneous accelerator/diagnostics expertise.
Impact Employment of PASI postdoc (collaboration with FNAL through PASI).
Start Year 2012