Towards more relaxed conditions for a gamma‐ray laser: Methods to realize induced transparency for nuclear resonant gamma radiation

Abstract

Nuclear quantum optics deals with the resonant interaction of gamma-radiation and nuclei, generally incorporated in a solid-state material. Single gamma-rays interact with an ensemble of nuclei. The properties of the resonantly forward-scattered gamma-radiation depend on the details of the interaction. An external modification of the nuclear energies will influence the interactions, and hence the properties of the radiation. Several techniques are proposed to reduce the resonant absorption of the gamma-rays, creating a nuclear medium that is partially transparent: nuclear-level-mixing induced transparency, modification of nuclear levels by means of an optical laser, phase-shift-induced transparency. Interference is crucial in all this. The partial transparency could be exploited to study special effects such as slow gamma-radiation and gain without population inversion. It could also be of importance for the realization of a gamma-ray laser.Less than expected absorption of gamma rays at nuclear level crossing (red arrow).

Cavity with Iron Nuclei Slows Down X Rays

“…Also coherent storage of light via rapid control of the applied quantization field has been achieved [10]. Other experiments with nuclei observed electromagnetically induced transparency [15], related spontaneously generated coherences with equivalent susceptibilites [16], or other transparency mechanisms [11,26]. However, these experiments did not study the delay or the actual pulse propagation.…”

Tunable Subluminal Propagation of Narrow-band X-Ray Pulses

“…Comparing it to the envelope integral in Eq. (25) and noting that c ∂k R ∂ω ω0 = n R (ω 0 ) + ∂n R ∂ω ω0 ω 0 , we can identify…”

“…Also coherent storage of light via rapid control of the applied quantization field has been achieved [10]. Other experiments with nuclei observed electromagnetically induced transparency [15], related spontaneously generated coherences with equivalent susceptibilites [16], or other transparency mechanisms [11,25]. However, these experiments did not study the delay or the actual pulse propagation.…”

Femtosecond pumping of nuclear isomeric states by the Coulomb collision of ions with quivering electrons

“…For these potential applications shown above, especially for nuclear gamma-ray lasers, where the lifetimes of excited states as short as nanosecond or even shorter are required [14,15], due to the relatively large emission linewidth of Doppler broadening. From the experimental point of view, the bottleneck of nuclear gamma-ray lasers appears as how to pump excited states efficiently.…”

“…The temperature of Kr ions is fitted to be T = (15 ± 4) keV. By integrating the area under the quasi-Boltzmann distribution curve, and taking the average Kr charge state to be 14 + according to ADK model [32], we estimate the total number of the Kr atoms in the laser spot to be 4.5×10 15 in one shot, and then the total number of the 83 Kr atoms is…”