The current lasers are at 500-1000 joules.
The favorable scaling of electron-positron pairs with laser energy obtained in these experiments suggests that, at a laser intensity and pulse duration comparable to what is available, near-future 10-kilojoule-class lasers would provide 100 times higher antimatter yield.
This would be about 100 trillion positron pairs or 10^14.
There are many interesting applications that start becoming feasible if you can regularly and quickly generate 10^19 positrons in less than 1000 seconds.
A 1 gigawatt antimatter ignited nuclear fusion generator becomes possible. 10^19 positrons can be used to trigger deuterium tritium fusion.
Laser production of copious positrons from the vacuum occurs when the laser intensity gets higher than 10^23 Watts per cm squared.
Physical Review Letters - Scaling the Yield of Laser-Driven Electron-Positron Jets to Laboratory Astrophysical Applications
Researchers report new experimental results obtained on three different laser facilities that show directed laser-driven relativistic electron-positron jets with up to 30 times larger yields than previously obtained and a quadratic (∼E2L) dependence of the positron yield on the laser energy. This favorable scaling stems from a combination of higher energy electrons due to increased laser intensity and the recirculation of MeV electrons in the mm-thick target. Based on this scaling, first principles simulations predict the possibility of using such electron-positron jets, produced at upcoming high-energy laser facilities, to probe the physics of relativistic collisionless shocks in the laboratory.