Proposed scheme produces ultrabright attosecond gamma-ray bursts

Ultrashort, bright gamma rays could be used to study nuclear structures, new particles, ultrafast dynamic processes, and astrophysical phenomena. Interactions between laser and plasma can generate ultrashort and ultrabright gamma rays, but it has proved very difficult to produce gamma rays of attosecond duration with photon energy above 100 MeV.

Hu et al. proposed an efficient, all-optical scheme for producing a string of gamma ray bursts with a duration of 367 attoseconds and photon energy up to 500 MeV. 3D particle-in-cell simulations demonstrated the interaction of a left-hand circularly polarized Laguerre-Gaussian laser pulse with near-critical-density plasma in the form of a nanotube foam target can generate a train of ultrabright, attosecond gamma rays with a brilliance billions of times brighter than the sun.

Gamma rays produced with this scheme also have a tunable angular momentum. The authors believe this method improved the peak brilliance and orbital angular momentum of the gamma ray photons compared to photons produced by other schemes.

“The obtained gamma rays have significant and broad applications in material science, nuclear physics and antimatter physics, such as production of electron-positron pairs with orbital angular momentum,” said author Yan-Ting Hu. “Our approach opens up a promising way to study many astrophysical phenomena, including gamma ray bursts, cosmic ray acceleration and emission from pulsars.”

The group led by Tong-Pu Yu will focus on generating a single isolated gamma ray bunch of attosecond duration by shortening the pulse duration. This ultrashort single gamma ray bunch would have applications in ultrafast imaging as well as fundamental science.

Source: “Attosecond gamma-ray vortex generation in near-critical-density plasma driven by twisted laser pulses,” by Yan-Ting Hu, Jie Zhao, Hao Zhang, Yu Lu, Wei-Quan Wang, Li-Xiang Hu, Fu-Qiu Shao, and Tong-Pu Yu, Applied Physics Letters (2021). The article can be accessed at https://aip.scitation.org/doi/full/10.1063/5.0028203 .