Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Laser structured micro-targets generate MeV electron temperature at $4
  \times 10^{16}$ W/cm$^2$   Relativistic temperature electrons higher than 0.5 MeV are generated
typically with laser intensities of about 10$^{18}$ W/cm$^{2}$. Their
generation with high repetition rate lasers that operate at non-relativistic
intensities ($\simeq$10$^{16}$ W/cm$^{2}$) is cardinal for the realization of
compact, ultra-short, bench-top electron sources. New strategies, capable of
exploiting different aspects of laser-plasma interaction, are necessary for
reducing the required intensity. We report here, a novel technique of dynamic
target structuring of microdroplets, capable of generating 200 keV and 1 MeV
electron temperatures at 1/100th of the intensity required by ponderomotive
scaling($10^{18}$ W/cm$^2$) to generate relativistic electron temperature.
Combining the concepts of pre-plasma tailoring, optimized scale length and
micro-optics, this method achieves two-plasmon decay boosted electron
acceleration with "non-ideal" ultrashort (25 fs) pulses at $4\times10^{16}$
W/cm$^2$, only. With shot repeatability at kHz, this precise in-situ targetry
produces directed, imaging quality beam-like electron emission up to 6 MeV with
milli-joule class lasers, that can be transformational for time-resolved,
microscopic studies in all fields of science.

14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
19
The categories of this paper are: eess
1
The categories of this paper are: cs
26
The categories of this paper are: bayes-an
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
27
The categories of this paper are: comp-gas
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
13
The categories of this paper are: quant-ph
20
The categories of this paper are: acc-phys