529 research outputs found
The SPARC_LAB Thomson source
The SPARC_LAB Thomson source is a compact X-ray source based on the Thomson backscattering process presently under its second phase of commissioning at the LNF. The electron beam energy ranges between 30 and 150 MeV, the electrons collide head-on with the Ti:Sapphire FLAME laser pulse the energy of which ranges between 1 and 5 J with pulse lengths in the 25 fs–10 ps range, this provides an X-ray energy tunability in the range of 20–500 keV, with the further capability to generate strongly non-linear phenomena and to drive diffusion processes due to multiple and plural scattering effects. The experimental results of the obtained X-ray radiation are presented
Electron beam transfer line design for plasma driven Free Electron Lasers
Plasma driven particle accelerators represent the future of compact
accelerating machines and Free Electron Lasers are going to benefit from these
new technologies. One of the main issue of this new approach to FEL machines is
the design of the transfer line needed to match of the electron-beam with the
magnetic undulators. Despite the reduction of the chromaticity of plasma beams
is one of the main goals, the target of this line is to be effective even in
cases of beams with a considerable value of chromaticity. The method here
explained is based on the code GIOTTO [1] that works using a homemade genetic
algorithm and that is capable of finding optimal matching line layouts directly
using a full 3D tracking code.Comment: 9 Pages, 4 Figures. A related poster was presented at EAAC 201
Linearly independent pure-state decomposition and quantum state discrimination
We put the pure-state decomposition mathematical property of a mixed state to
a physical test. We begin by characterizing all the possible decompositions of
a rank-two mixed state by means of the complex overlap between two involved
states. The physical test proposes a scheme of quantum state recognition of one
of the two linearly independent states which arise from the decomposition. We
find that the two states associated with the balanced pure-state decomposition
have the smaller overlap modulus and therefore the smallest probability of
being discriminated conclusively, while in the nonconclusive scheme they have
the highest probability of having an error. In addition, we design an
experimental scheme which allows to discriminate conclusively and optimally two
nonorthogonal states prepared with different a priori probabilities. Thus, we
propose a physical implementation for this linearly independent pure-state
decomposition and state discrimination test by using twin photons generated in
the process of spontaneous parametric down conversion. The information-state is
encoded in one photon polarization state whereas the second single-photon is
used for heralded detection.Comment: 6 pages, 5 figures, Submitted to Phys. Rev.
Plasma boosted electron beams for driving Free Electron Lasers
In this paper, we report results of simulations, in the framework of both
EuPRAXIA \cite{Walk2017} and EuPRAXIA@SPARC\_LAB \cite{Ferr2017} projects,
aimed at delivering a high brightness electron bunch for driving a Free
Electron Laser (FEL) by employing a plasma post acceleration scheme. The
boosting plasma wave is driven by a tens of \SI{}{\tera\watt} class laser and
doubles the energy of an externally injected beam up to \GeV{1}. The injected
bunch is simulated starting from a photoinjector, matched to plasma, boosted
and finally matched to an undulator, where its ability to produce FEL radiation
is verified to yield O(\num{e11}) photons per shot at \nm{2.7}.Comment: 5 pages, 2 figure
EuPRAXIA@SPARC_LAB: the high-brightness RF photo-injector layout proposal
At EuPRAXIA@SPARC_LAB, the unique combination of an advanced high-brightness
RF injector and a plasma-based accelerator will drive a new multi-disciplinary
user-facility. The facility, that is currently under study at INFN-LNF
Laboratories (Frascati, Italy) in synergy with the EuPRAXIA collaboration, will
operate the plasma-based accelerator in the external injection configuration.
Since in this configuration the stability and reproducibility of the
acceleration process in the plasma stage is strongly influenced by the
RF-generated electron beam, the main challenge for the RF injector design is
related to generating and handling high quality electron beams. In the last
decades of R&D activity, the crucial role of high-brightness RF photo-injectors
in the fields of radiation generation and advanced acceleration schemes has
been largely established, making them effective candidates to drive
plasma-based accelerators as pilots for user facilities. An RF injector
consisting in a high-brightness S-band photo-injector followed by an advanced
X-band linac has been proposed for the EuPRAXIA@SPARC_LAB project. The electron
beam dynamics in the photo-injector has been explored by means of simulations,
resulting in high-brightness, ultra-short bunches with up to 3 kA peak current
at the entrance of the advanced X-band linac booster. The EuPRAXIA@SPARC_LAB
high-brightness photo-injector is described here together with performance
optimisation and sensitivity studies aiming to actual check the robustness and
reliability of the desired working point.Comment: 5 pages,5 figures, EAAC201
Thermal issues for the optical transition radiation screen for the ELI-NP compton gamma source
A high brightness electron LINAC is being built in the Compton Gamma Source at the ELI Nuclear Physics facility in Romania. To achieve the design luminosity, a train of 32 bunches, 16 ns spaced, with a nominal charge of 250 pC will collide with a laser beam in two interaction points. Electron beam spot size is measured with Optical Transition Radiation (OTR) profile monitors. In order to measure the beam properties, the OTR screens must sustain the thermal and mechanical stress due to the energy deposited by bunches. This paper is an ANSYS study of the issues due to the high energy transferred to the OTR screens. Thermal multicycle analysis will be shown; each analysis will be followed by a structural analysis in order to investigate the performance of the materia
Quadrupole scan emittance measurements for the ELI-NP compton gamma source
The high brightness electron LINAC of the Compton
Gamma Source at the ELI Nuclear Physics facility in Roma-
nia is accelerating a train of 32 bunches with a nominal total
charge of
250 pC
and nominal spacing of
16 ns
. To achieve
the design gamma flux, all the bunches along the train must
have the designed Twiss parameters. Beam sizes are mea-
sured with optical transition radiation monitors, allowing a
quadrupole scan for Twiss parameters measurements. Since
focusing the whole bunch train on the screen may lead to
permanent screen damage, we investigate non-conventional
scans such as scans around a maximum of the beam size
or scans with a controlled minimum spot size. This paper
discusses the implementation issues of such a technique in
the actual machine layou
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