AUTHOR=Aymar Galen , Becker Tobias , Boogert Stewart , Borghesi Marco , Bingham Robert , Brenner Ceri , Burrows Philip N. , Ettlinger Oliver C. , Dascalu Titus , Gibson Stephen , Greenshaw Timothy , Gruber Sylvia , Gujral Dorothy , Hardiman Claire , Hughes Jonathan , Jones W. G. , Kirkby Karen , Kurup Ajit , Lagrange Jean-Baptiste , Long Kenneth , Luk Wayne , Matheson John , McKenna Paul , McLauchlan Ruth , Najmudin Zulfikar , Lau Hin T. , Parsons Jason L. , Pasternak Jaroslaw , Pozimski Juergen , Prise Kevin , Puchalska Monika , Ratoff Peter , Schettino Giuseppe , Shields William , Smith Susan , Thomason John , Towe Stephen , Weightman Peter , Whyte Colin , Xiao Rachel 

TITLE=LhARA: The Laser-hybrid Accelerator for Radiobiological Applications

JOURNAL=Frontiers in Physics

VOLUME=Volume 8 - 2020

YEAR=2020

URL=https://www.frontiersin.org/journals/physics/articles/10.3389/fphy.2020.567738

DOI=10.3389/fphy.2020.567738

ISSN=2296-424X

ABSTRACT=The `Laser-hybrid Accelerator for Radiobiological Applications',
LhARA, is conceived as a novel, flexible facility dedicated
to the study of radiobiology.
The technologies demonstrated in LhARA, which have wide application,
will be developed to allow particle-beam therapy to be delivered in a
new regimen, combining a variety of ion species in a single
treatment fraction and exploiting ultra-high dose rates.
LhARA will be a hybrid accelerator system in which laser interactions
drive the creation of a large flux of protons or light ions that are
captured using a plasma (Gabor) lens and formed into a beam.
The laser-driven source allows protons and ions to be captured at
energies significantly above those that pertain in conventional
facilities, thus evading the current space-charge limit on the
instantaneous dose rate that can be delivered.
The laser-hybrid approach, therefore, will allow the radiobiology that
determines the response of tissue to ionising
radiation to be studied with protons and light ions using a wide variety
of time structures, spectral distributions, and spatial configurations 
at instantaneous dose rates up to and significantly beyond the ultra-high
dose-rate `FLASH' regime.

It is proposed that LhARA be developed in two stages.
In the first stage, a programme of \emph{in vitro} radiobiology will be 
served with proton beams with energies between 10\,MeV and 15\,MeV.
In stage two, the beam will be accelerated using a fixed-field
alternating-gradient accelerator (FFA).
This will allow experiments to be carried out \emph{in vitro} and \emph{in vivo}
with proton beam energies of up to 127\,MeV.
In addition, ion beams with energies up to 33.4\,MeV per nucleon
will be available for \emph{in vitro} and \emph{in vivo} experiments.
This paper presents the conceptual design for LhARA and the R\&D
programme by which the LhARA consortium seeks to establish the
facility.