The design of a high flux VUV beamline for low energy photons

TL;DR

This paper presents a novel design for a VUV beamline at SSRF that enhances flux and resolution for low-energy photons down to 7 eV, overcoming reflectivity challenges with a variable angle VLPGM and VGD system.

Contribution

The work introduces a variable angle VLPGM with varied grating depth to achieve high flux and resolution for low-energy VUV photons, addressing reflectivity issues.

Findings

Achieves broad energy coverage down to 7 eV.

Enhances flux and resolution for ARPES measurements.

Overcomes reflectivity challenges at low photon energies.

Abstract

A VUV beamline at SSRF for ARPES measurements are designed. To increase the resolution and bulk sensitivity, the photon energy as low as 7 eV is desired. Because the reflectivity for p-polarized photons strongly decreases when the photon energy is below 30 eV, the design of high flux beamline for low energy VUV photons is a challenge. This work shows a variable including angle VLPGM with varied grating depth (VGD) which can achieve both high resolution and high flux with broad energy coverage.