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Pair creation and an x-ray free electron laser
R Alkofer1, M B Hecht, C D Roberts
1Institut für Theoretische Physik, Universität Tübingen, Auf der Morgenstelle 14, D-72076 Tübingen, Germany.
Physical Review Letters
|November 3, 2001
Summary
Focused X-ray free electron laser beams may trigger spontaneous electron-positron pair production from the quantum electrodynamics (QED) vacuum. This process involves repeated particle creation and annihilation cycles, yielding hundreds of pairs per laser period.
Area of Science:
- Quantum electrodynamics (QED)
- High-energy physics
- Laser-matter interactions
Background:
- The quantum vacuum is not empty but a dynamic medium.
- High-intensity lasers can probe fundamental physics.
- Electron-positron pair production is a key QED prediction.
Purpose of the Study:
- Investigate spontaneous electron-positron pair production.
- Explore feasibility at proposed X-ray Free Electron Laser (XFEL) facilities.
- Analyze particle production dynamics with laser frequency.
Main Methods:
- Utilized a quantum kinetic equation.
- Simulated focused X-ray laser beam interactions.
- Analyzed particle creation and annihilation cycles.
Main Results:
- Achievable conditions at planned XFELs can initiate pair production.
- Repeated particle creation and annihilation cycles occur.
- Peak particle number density is independent of laser frequency.
Conclusions:
- Spontaneous electron-positron pair production is possible at XFELs.
- Hundreds of particle pairs can be produced per laser period.
- This opens new avenues for vacuum physics research.