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Materials Data on LaBC by Materials Project

LaBC crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. there are five inequivalent La sites. In the first La site, La is bonded in a 11-coordinate geometry to five B and six C atoms. There are a spread of La–B bond distances ranging from 2.70–3.06 Å. There are a spread of La–C bond distances ranging from 2.68–3.17 Å. In the second La site, La is bonded in a 8-coordinate geometry to three B and five C atoms. There are a spread of La–B bond distances ranging from 2.86–3.03 Å. There are a spread of La–C bond distances ranging from 2.60–3.08 Å. In the third La site, La is bonded in a 5-coordinate geometry to five B and five C atoms. There are a spread of La–B bond distances ranging from 3.01–3.11 Å. There are a spread of La–C bond distances ranging from 2.60–2.98 Å. In the fourth La site, La is bonded in a 2-coordinate geometry to six B and four C atoms. There are a spread of La–B bond distances ranging from 2.80–2.92 Å. There are a spread of La–C bond distances ranging from 2.76–2.82 Å. In the fifth La site, La is bonded in a 11-coordinate geometry to six B and five C atoms. There are a spread of La–B bond distances ranging from 2.77–3.08 Å. There are a spread of La–C bond distances ranging from 2.70–3.12 Å. There are five inequivalent B sites. In the first B site, B is bonded in a distorted single-bond geometry to five La and one C atom. The B–C bond length is 1.48 Å. In the second B site, B is bonded in a bent 150 degrees geometry to five La and two C atoms. Both B–C bond lengths are 1.48 Å. In the third B site, B is bonded in a bent 150 degrees geometry to five La and two C atoms. There is one shorter (1.47 Å) and one longer (1.49 Å) B–C bond length. In the fourth B site, B is bonded in a distorted single-bond geometry to six La and one C atom. The B–C bond length is 1.50 Å. In the fifth B site, B is bonded in a distorted bent 150 degrees geometry to four La and two C atoms. There is one shorter (1.46 Å) and one longer (1.48 Å) B–C bond length. There are five inequivalent C sites. In the first C site, C is bonded in a distorted bent 150 degrees geometry to five La and two B atoms. In the second C site, C is bonded in a distorted bent 150 degrees geometry to five La and two B atoms. In the third C site, C is bonded in a 6-coordinate geometry to five La and one B atom. In the fourth C site, C is bonded in a 1-coordinate geometry to five La and one B atom. In the fifth C site, C is bonded in a distorted bent 150 degrees geometry to five La and two B atoms.

36 MATERIALS SCIENCE↗

X-ray Free Electron Laser Accelerator Lattice Design Using Laser-Assisted Bunch Compression

We report the start-to-end modeling of our accelerator lattice design employing a laser-assisted bunch compression (LABC) scheme in an X-ray free electron laser (XFEL), using the proposed Matter-Radiation Interactions in Extremes (MaRIE) XFEL parameters. The accelerator lattice utilized a two-stage bunch compression scheme, with the first bunch compressor performing a conventional bulk compression enhancing the beam current from 20 A to 500 A, at 750 MeV. The second bunch compression was achieved by modulating the beam immediately downstream of the first bunch compressor by a laser with 1-μm wavelength in a laser modulator, accelerating the beam to the final energy of 12 GeV, and compressing the individual 1-μm periods of the modulated beam into a sequence of microbunches with 3-kA current spikes by the second bunch compressor. The LABC architecture presented had been developed based on the scheme of enhanced self-amplified spontaneous emission (ESASE), but operated in a disparate regime of parameters. Enabled by the novel technology of the cryogenic normal conducting radiofrequency photoinjector, we investigated an electron beam with ultra-low emittance at the starting point of the lattice design. Our work aimed at mitigating the well-known beam instabilities to preserve the beam emittance and suppress the energy spread growth.

43 PARTICLE ACCELERATORS↗