相关论文: Efficient positronium laser excitation for antihyd…

We experimentally demonstrate ultrafast dynamic of generation of a strong 337-nm nitrogen laser by injecting an external seed pulse into a femtosecond laser filament pumped by a circularly polarized laser pulse. In the pump-probe scheme, it…

Rydberg states of atomic helium with principal quantum numbers ranging from n=20 to n=100 have been prepared by non-resonance-enhanced single-color two-photon excitation from the metastable 2 {^3}S{_1} state. Photoexcitation was carried out…

The scattering of ortho-positronium (Ps) by hydrogen atoms has been investigated in a five-state coupled-channel model allowing for Ps(1s)H(2s,2p) and Ps(2s,2p)H(1s) excitations using a recently proposed electron-exchange model potential.…

Plasma-based acceleration of positrons attracts extensive interests due to the ultrahigh accelerating gradient and ultrashort duration, while generating wakefield positron beam by the inherent injection is still a great challenge. Here, we…

Antihydrogen is produced by mixing an antiproton and a positron plasma in a cryogenic electromagnetic trap. The dominant antihydrogen formation mechanism is three-body recombination, while the subsequent level population evolution is…

Intense positron beams can be prepared via electro production with the reaction $e^{-} + e^{-} \rightarrow e^{-}+e^{+}+e^{-}+e^{-}$ due to the availability of high current electron beams. Head on collisions inside of a magnetic field of a…

Two-dimension Particle-in-cell simulations for laser plasma interaction with laser intensity of $10^{16} W/cm^2$, plasma density range of 0.01-0.28$n_c$ and scale length of $230 -330 \mu m$ showed significant pump depletion of the laser…

Positronium (Ps) formation on the surface of clean polycrystalline copper (Cu), highly oriented pyrolytic graphite (HOPG) and multi layer graphene (MLG) grown on a polycrystalline copper substrate has been investigated as a function of…

We propose a laser cooling technique in which atoms are selectively excited to a dressed metastable state whose light shift and decay rate are spatially correlated for Sisyphus cooling. The case of cooling magnetically trapped…

The process of nuclear excitation by electron capture in plasma environments generated by the interaction of ultra-strong optical lasers with solid-state samples is investigated theoretically. With the help of a plasma model we perform a…

We implement high-efficiency coherent excitation to a Rydberg state using stimulated Raman adiabatic passage in a cold atom electron and ion source. We achieve an efficiency of 60% averaged over the laser excitation volume with a peak…

A strong laser field and the Coulomb field of a nucleus can produce e^{+}e^{-} pairs. It is shown for the first time that there is a large probability that electrons and positrons created in this process collide after one or several…

The intense emission of 511 keV photons from the Galactic center and within terrestrial thunderstorms is attributed to the formation of parapositronia' clouds. Unbound electron-positron pairs and positronia can be created by strong…

We present a description of the GBAR positron (e+) trapping apparatus, which consists of a three stage Buffer Gas Trap (BGT) followed by a High Field Penning Trap (HFT), and discuss its performance. The overall goal of the GBAR experiment…

The optimal parameters for nuclear excitation by electron capture in plasma environments generated by the interaction of ultra-strong optical lasers with solid matter are investigated theoretically. As a case study we consider a 4.85 keV…

Frequency up-conversion of a few low-energy photons into a single high-energy photon contributes to imaging, light sources, and detection. However, the up-converting of many photons exhibits negligible efficiency. Up-conversion through…

When a relativistically intense p-polarized laser pulse is grazingly incident onto a planar solid-state target, a slightly superluminal field structure is formed near the target surface due to the incident and reflected waves superposition.…

As first shown by Shvartsman (1970), a neutron star accreting close to the Eddington limit must acquire a positive charge in order for electrons and protons to move at the same speed. The resulting electrostatic field may contribute to…

Propagation of ultrarelativistically intense laser pulse in a self-trapping mode in a near critical density plasma makes it possible to produce electron bunches of extreme parameters appropriate for different state of art applications.…

A new scheme for injection and acceleration of electrons in wakefield accelerators is suggested based on the co-action of a laser pulse and an electron beam. This synergy leads to stronger wakefield generation and higher energy gain in the…