3,812 research outputs found
Linear Accelerator Test Facility at LNF Conceptual Design Report
Test beam and irradiation facilities are the key enabling infrastructures for
research in high energy physics (HEP) and astro-particles. In the last 11 years
the Beam-Test Facility (BTF) of the DA{\Phi}NE accelerator complex in the
Frascati laboratory has gained an important role in the European
infrastructures devoted to the development and testing of particle detectors.
At the same time the BTF operation has been largely shadowed, in terms of
resources, by the running of the DA{\Phi}NE electron-positron collider. The
present proposal is aimed at improving the present performance of the facility
from two different points of view: extending the range of application for the
LINAC beam extracted to the BTF lines, in particular in the (in some sense
opposite) directions of hosting fundamental physics and providing electron
irradiation also for industrial users; extending the life of the LINAC beyond
or independently from its use as injector of the DA{\Phi}NE collider, as it is
also a key element of the electron/positron beam facility. The main lines of
these two developments can be identified as: consolidation of the LINAC
infrastructure, in order to guarantee a stable operation in the longer term;
upgrade of the LINAC energy, in order to increase the facility capability
(especially for the almost unique extracted positron beam); doubling of the BTF
beam-lines, in order to cope with the signicant increase of users due to the
much wider range of applications.Comment: 71 page
Corrugated structure insertion for extending the SASE bandwidth up to 3% at the European XFEL
The usage of x-ray free electron laser (XFEL) in femtosecond
nanocrystallography involves sequential illumination of many small crystals of
arbitrary orientation. Hence a wide radiation bandwidth will be useful in order
to obtain and to index a larger number of Bragg peaks used for determination of
the crystal orientation. Considering the baseline configuration of the European
XFEL in Hamburg, and based on beam dynamics simulations, we demonstrate here
that the usage of corrugated structures allows for a considerable increase in
radiation bandwidth. Data collection with a 3% bandwidth, a few microjoule
radiation pulse energy, a few femtosecond pulse duration, and a photon energy
of 5.4 keV is possible. For this study we have developed an analytical modal
representation of the short-range wake function of the flat corrugated
structures for arbitrary offsets of the source and the witness particles.Comment: 29 pages, 17 figure
Beam Cleaning and Collimation Systems
Collimation systems in particle accelerators are designed to dispose of
unavoidable losses safely and efficiently during beam operation. Different
roles are required for different types of accelerator. The present state of the
art in beam collimation is exemplified in high-intensity, high-energy
superconducting hadron colliders, like the CERN Large Hadron Collider (LHC),
where stored beam energies reach levels up to several orders of magnitude
higher than the tiny energies required to quench cold magnets. Collimation
systems are essential systems for the daily operation of these modern machines.
In this document, the design of a multistage collimation system is reviewed,
taking the LHC as an example case study. In this case, unprecedented cleaning
performance has been achieved, together with a system complexity comparable to
no other accelerator. Aspects related to collimator design and operational
challenges of large collimation systems are also addressed.Comment: 35 pages, contribution to the 2014 Joint International Accelerator
School: Beam Loss and Accelerator Protection, Newport Beach, CA, USA , 5-14
Nov 201
Crystal Channelling in Accelerators
Crystal lattice can trap and channel particle beams along major
crystallographic directions. In a bent crystal, the channelled particles follow
the bend. This makes a basis for an elegant technique of beam steering by means
of bent channelling crystals, experimentally demonstrated from 3 MeV to 1 TeV.
This technique was strongly developed in recent studies at CERN, FNAL, IHEP,
and BNL, and can lead to interesting applications also at the LHC, such as
crystal collimation making a collider cleaner by an order of magnitude. We
review recent developments in the field and show outlook for the future.Comment: Invited talk at 10th European Particle Accelerator Conference (EPAC
06), Edinburgh, UK, 26-30 Jun 200
Perspectives of Imaging of Single Protein Molecules with the Present Design of the European XFEL. - Part I - X-ray Source, Beamlime Optics and Instrument Simulations
The Single Particles, Clusters and Biomolecules (SPB) instrument at the
European XFEL is located behind the SASE1 undulator, and aims to support
imaging and structure determination of biological specimen between about 0.1
micrometer and 1 micrometer size. The instrument is designed to work at photon
energies from 3 keV up to 16 keV. This wide operation range is a cause for
challenges to the focusing optics. In particular, a long propagation distance
of about 900 m between x-ray source and sample leads to a large lateral photon
beam size at the optics. The beam divergence is the most important parameter
for the optical system, and is largest for the lowest photon energies and for
the shortest pulse duration (corresponding to the lowest charge). Due to the
large divergence of nominal X-ray pulses with duration shorter than 10 fs, one
suffers diffraction from mirror aperture, leading to a 100-fold decrease in
fluence at photon energies around 4 keV, which are ideal for imaging of single
biomolecules. The nominal SASE1 output power is about 50 GW. This is very far
from the level required for single biomolecule imaging, even assuming perfect
beamline and focusing efficiency. Here we demonstrate that the parameters of
the accelerator complex and of the SASE1 undulator offer an opportunity to
optimize the SPB beamline for single biomolecule imaging with minimal
additional costs and time. Start to end simulations from the electron injector
at the beginning of the accelerator complex up to the generation of diffraction
data indicate that one can achieve diffraction without diffraction with about
0.5 photons per Shannon pixel at near-atomic resolution with 1e13 photons in a
4 fs pulse at 4 keV photon energy and in a 100 nm focus, corresponding to a
fluence of 1e23 ph/cm^2. This result is exemplified using the RNA Pol II
molecule as a case study
Design and optimization of a compact laser-driven proton beamline
Laser-accelerated protons, generated by irradiating a solid target with a short, energetic laser pulse at high intensity (I > 1018W·cm-2), represent a complementary if not outperforming source compared to conventional accelerators, due to their intrinsic features, such as high beam charge and short bunch duration. However, the broadband energy spectrum of these proton sources is a bottleneck that precludes their use in applications requiring a more reduced energy spread. Consequently, in recent times strong effort has been put to overcome these limits and to develop laser-driven proton beamlines with low energy spread. In this paper, we report on beam dynamics simulations aiming at optimizing a laser-driven beamline - i.e. a laser-based proton source coupled to conventional magnetic beam manipulation devices - producing protons with a reduced energy spread, usable for applications. The energy range of investigation goes from 2 to 20 MeV, i.e. the typical proton energies that can be routinely obtained using commercial TW-power class laser systems. Our beamline design is capable of reducing the energy spread below 20%, still keeping the overall transmission efficiency around 1% and producing a proton spot-size in the range of 10 mm2. We briefly discuss the results in the context of applications in the domain of Cultural Heritage
Laser Wire Scanner Compton Scattering Techniques for the Measurement of the Transverse Beam Size of Particle Beams at Future Linear Colliders
This archive summarizes a working paper and conference proceedings related to
laser wire scanner development for the Future Linear Collider (FLC) in the
years 2001 to 2006. In particular the design, setup and data taking for the
laser wire experiments at PETRA II and CT2 are described. The material is
focused on the activities undertaken by Royal Holloway University of London
(RHUL).Comment: 61 page
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