Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Terahertz Acceleration Technology Towards Compact Light Sources   The concepts in this thesis comprise three groups focusing on: (1) fast
electron sources, (2) THz injectors, and (3) THz linacs. First, the feasibility
of ultrafast, high-yield electron emitters based on nanostructured cathodes is
demonstrated. Benefitting from field enhancement effects, namely
tip-enhancement and plasmonic enhancement, laser-induced field emission is
realized over large, dense and highly uniform field emitter arrays. The
theoretical principles of these field emitter arrays are studied and their
suitability for pico-Coulomb charge production over femtosecond time-scales is
confirmed. In the framework of THz injectors, two ground-breaking concepts
including ultrafast single-cycle THz guns and segmented THz electron
accelerator and manipulator (STEAM) devices are developed and tested. The
possibility of using transient fields to realize ultrahigh acceleration
gradients close to 0.5 GeV/m is confirmed. Specifically, a STEAM device capable
of performing multiple high-field operations on the 6D-phase-space of
ultrashort electron bunches is demonstrated. With this single device, powered
by few-micro-Joule, single-cycle, 0.3 THz pulses, we demonstrated record
THz-acceleration of >30 keV, streaking with <10fs resolution, focusing with >2
kT/m strength, compression to ~ 100 fs as well as real-time switching between
these modes of operation. Travelling wave THz linacs based on dielectric-loaded
metallic waveguides operating under few-cycle excitations are proposed. Based
on this concept, keV-level energy gain through a linear accelerator using
optically-generated THz pulses is demonstrated. Moreover, the possibility of
electron acceleration to tens of MeV with millijoule level THz pulses is
theoretically shown. The final goal of the above studies is a fully THz-driven
compact light source facility, whose start-to-end simulation is fulfilled in
this thesis.

12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
26
The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
29
The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
8
The categories of this paper are: hep-ex
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph