-
M. Fuchs,
R. Weingartner,
A. Popp,
Zs. Major, S. Becker,
J. Osterhoff,
T. Seggebrock,
R. Hörlein,
G. D. Tsakiris,
U. Schramm,
T. P. Rowlands-Rees,
S. M. Hooker,
D. Habs,
F. Krausz,
S. Karsch,
F. Grüner
[show abstract]
[hide abstract]
ABSTRACT: Latest developments in the field of laser-wakefield accelerators (LWFAs)
have led to relatively stable electron beams in terms of peak energy,
charge, pointing and divergence from mm-sized accelerators. Simulations
and LWFA theory indicate that these beams have low transverse emittances
and ultrashort bunch durations on the order of ~10 fs. These features
make LWFAs perfectly suitable for driving high-brightness X-ray
undulator sources and free-electron lasers (FELs) on a
university-laboratory scale. With the detection of soft-X-ray radiation
from an undulator source driven by laser-wakefield accelerated
electrons, we succeeded in achieving a first milestone on this path. The
source delivers remarkably stable photon beams which is mainly due to
the stable electron beam and our miniature magnetic quadrupole lenses,
which significantly reduce its divergence and angular shot-to-shot
variation. An increase in electron energy allows for compact, tunable,
hard-X-ray undulator sources. Improvements of the electron beams in
terms of charge and energy spread will put table-top FELs within reach.
03/2010; 1228:295-299.
-
[show abstract]
[hide abstract]
ABSTRACT: Laser-plasma accelerators are expected to deliver electron bunches with high space charge fields. Several recent publications have addressed the impact of space charge effects on such bunches after the extraction into vacuum. Artifacts due to the approximation of retardation effects are addressed, which are typically either neglected or approximated. We discuss a much more appropriate calculation for the case of laser wakefield acceleration with negligible retardation artifacts due to the calculation performed in the mean rest frame. This presented calculation approach also aims at a validation of other simulation approaches.
07/2009;
-
S. Becker,
M. Bussmann,
S. Raith,
M. Fuchs,
R. Weingartner,
P. Kunz,
W. Lauth,
S. Schramm,
M. El Ghazaly,
F Grüner,
H. Backe,
D. Habs
[show abstract]
[hide abstract]
ABSTRACT: The application of quadrupole-devices with high field gradients and small apertures requires precise control over higher order multipole field components. We present a new scheme for performance control and tuning, which allows the illumination of most of the quadrupole-device aperture because of the reduction of higher order field components. Consequently, the size of the aperture can be minimized to match the beam size achieving field gradients of up to 500 T/m at good imaging quality. The characterization method based on a Hall probe measurement and a Fourier analysis was confirmed using the high quality electron beam at the Mainz Microtron MAMI.
02/2009;
-
J Osterhoff,
A Popp,
Zs Major,
B Marx,
T P Rowlands-Rees,
M Fuchs,
M Geissler,
R Hörlein,
B Hidding, S Becker,
E A Peralta,
U Schramm,
F Grüner,
D Habs,
F Krausz,
S M Hooker,
S Karsch
[show abstract]
[hide abstract]
ABSTRACT: Laser-driven, quasimonoenergetic electron beams of up to approximately 200 MeV in energy have been observed from steady-state-flow gas cells. These beams emitted within a low-divergence cone of 2.1+/-0.5 mrad FWHM display unprecedented shot-to-shot stability in energy (2.5% rms), pointing (1.4 mrad rms), and charge (16% rms) owing to a highly reproducible gas-density profile within the interaction volume. Laser-wakefield acceleration in gas cells of this type provides a simple and reliable source of relativistic electrons suitable for applications such as the production of extreme-ultraviolet undulator radiation.
Physical Review Letters 09/2008; 101(8):085002. · 7.37 Impact Factor
-
M Schollmeier, S Becker,
M Geissel,
K A Flippo,
A Blazević,
S A Gaillard,
D C Gautier,
F Grüner,
K Harres,
M Kimmel, [......],
P Rambo,
U Schramm,
J Schreiber,
J Schütrumpf,
J Schwarz,
N A Tahir,
B Atherton,
D Habs,
B M Hegelich,
M Roth
[show abstract]
[hide abstract]
ABSTRACT: This Letter demonstrates the transporting and focusing of laser-accelerated 14 MeV protons by permanent magnet miniature quadrupole lenses providing field gradients of up to 500 T/m. The approach is highly reproducible and predictable, leading to a focal spot of (286 x 173) microm full width at half maximum 50 cm behind the source. It decouples the relativistic laser-proton acceleration from the beam transport, paving the way to optimize both separately. The collimation and the subsequent energy selection obtained are perfectly applicable for upcoming high-energy, high-repetition rate laser systems.
Physical Review Letters 09/2008; 101(5):055004. · 7.37 Impact Factor
-
F Grüner, S. Becker,
U Schramm,
T. Eichner,
M. Fuchs,
R. Weingartner,
D. Habs,
J. Meyer-ter-Vehn,
M Geissler,
M. Ferrario,
L. Serafini,
B. van der Geer,
H. Backe,
W. Lauth,
S. Reiche
[show abstract]
[hide abstract]
ABSTRACT: A recent breakthrough in laser-plasma accelerators, based upon ultrashort high-intensity lasers, demonstrated the generation of quasi-monoenergetic GeV-electrons. With future Petawatt lasers ultra-high beam currents of ~100 kA in ~10 fs can be expected, allowing for drastic reduction in the undulator length of free-electron-lasers (FELs). We present a discussion of the key aspects of a table-top FEL design, including energy loss and chirps induced by space-charge and wakefields. These effects become important for an optimized table-top FEL operation. A first proof-of-principle VUV case is considered as well as a table-top X-ray-FEL which may open a brilliant light source also for new ways in clinical diagnostics.
01/2007;
-
U. Schramm, S. Becker,
M. Geissler,
F. Gruner,
D. Habs,
S. Karsch,
F. Krausz,
J. Meyer-ter-Vehn,
K. Schmid,
J. Schreiber,
G. Tsakiris,
L. Veisz,
K. Witte
[show abstract]
[hide abstract]
ABSTRACT: Only recently a breakthrough in laser plasma acceleration has been achieved with the observation of intense (nC) mono-energetic (10% relative width) electron beams in the 100MeV energy range [1]. Above the wave-breaking threshold the electrons are trapped and accelerated in a single wake of the laser pulse, called bubble, according to PIC simulations [2]. At the MPQ Garching we plan to investigate the acceleration of electrons in this bubble regime by the use of 10 TW few-cycle laser pulse. As the pulse length of the few-cycle pulse of 5-10 fs remains below the plasma period also at comparatively high plasma densities, we expect the scheme to become more stable and efficient.
Particle Accelerator Conference, 2005. PAC 2005. Proceedings of the; 06/2005
-
S. Becker,
M. Bussmann,
S. Raith,
M. Fuchs,
R. Weingartner,
P. Kunz,
W. Lauth,
U Schramm,
M. El Ghazaly,
F Grüner,
H. Backe,
D. Habs
Physical Review Special Topics - Accelerators and Beams, v.12 (2009).
-
S Borneis, S Becker,
T Engel,
I Klaft,
O Klepper,
A Kohl,
T Kuhl,
D Marx,
K Meier,
R Neumann,
F Schmitt,
P Seelig,
L Volker
pages 150-153;
