Nuclear structure from light muonic atoms (Dr. B. Franke) / LWFA-driven hard X-ray sources at LEX and CALA (K. Khrennikov)
- Double Feature!
- Date: Dec 15, 2015
- Time: 02:30 PM - 04:00 PM (Local Time Germany)
- Speaker: Dr. Beatrice Franke, MPQ, Laser Spectroscopy Division / M.Sc. Konstantin Khrennikov, MPQ, Attosecond Physics Division
- Room: Herbert Walther Lecture Hall
- Host: MPQ
Nuclear structure from light muonic atoms (Dr. B. Franke)
Muonic atoms have an increased
sensitivity on finite size effects of the nucleus due to the ~200-fold
mass of the muon compared to the electron. The CREMA collaboration has
measured the Lamb shift in muonic hydrogen and muonic deuterium atoms,
as well as in muonic helium-4 and helium-3 ions. These measurements
allow to determine charge radii and other nuclear properties with
improved precision compared to previously conducted measurements.
Contributions to solving the proton radius puzzle as well as the
discrepancy in electronic isotope-shift measurements from the collected
data will be discussed. A status update of CREMA's ongoing data analysis
towards charge radius extractions of the deuteron, helion, and the
alpha particle will be given. Current analysis-related topics such as
theory issues and possible systematics will be shown, together with an
outlook for possible future measurements using bound muonic
systems.
LWFA-driven hard X-ray sources at LEX and CALA (K. Khrennikov)
We present data
on a various X-ray production schemes from laser-wakefield-driven
electron beams. This includes detailed electron beam characterization
measurements [1] from various gas target sources, comparing beam
properties form different targets. Since stable beams can now be
routinely achieved over a wide range of parameters, we show their use
for X-ray production by undulator radiation, betatron emission [2] and
Thomson scattering [3]. A quantitative phase-contrast tomogram of an
insect has been recorded with a 5-keV betatron source with few-micron
source size. We show that our method permits accurate reconstruction of
electron densities in the insect by comparing our reconstructed images
with electron-microscopy images. For Thomson scattering, we demonstrate
the onset of the nonlinear scattering regime by the spectral downshift
of the emitted radiation due to the transverse excursion of the electron
bunch in a colliding pulse with a0=0.9, and the presence of second and
third order harmonic emission. We will make a prognosis about the
source parameters with the LEX and CALA lasers, show the latest status
of the ongoing facility upgrade at Garching and present first electron
beam results with the upgraded 300 TW laser.
References:
[1] M. Heigoldt et
al, accepted by Phys. Rev. Spec. Top. Accel. Beams (2015)
[2] J. Wenz
et al., Nature Communications 6 7568 (2015)
[3] K. Khrennikov et al.,
Phys. Rev. Lett. 114 195003 (2015)