# Enhancing keV high harmonic signals generated by long-wave infrared lasers

## TL;DR

This paper demonstrates that adding a single-cycle 800 nm pulse to long-wave infrared laser-driven high harmonic generation significantly boosts keV X-ray signals, with potential for enhanced high-energy photon sources.

## Contribution

It introduces a novel method of increasing keV high harmonic signals by combining long-wave infrared lasers with a single-cycle 800 nm pulse, supported by single-atom simulations.

## Key findings

- X-ray signals in the 3.4 to 4 keV range are increased by over two orders of magnitude.
- Optimal ionization probability for phase matching is identified as 4.56x10^-5.
- Method enables more efficient generation of high-energy X-ray signals.

## Abstract

It is demonstrated by single-atom simulations that X-ray signals in the 3.4 to 4 keV region from an 8 micron laser driven high harmonic generation can be increased by more than two orders of magnitude when a single-cycle pulse centered at 800 nm is added. The ionization probability of a helium atom by the two-pulse field is set to 4.56x10^-5, which is needed for balancing the index of refraction of free electrons with that of neutral helium atoms to achieve phase matching.

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Source: https://tomesphere.com/paper/1904.10233