Facility Features

FACET-II Beam Parameters

FACET-II was commissioned 2020 - 2021.

The first full year of User programs with 10 GeV compressed electron beams is began in the fall of 2021 and ran until August 2022. 


Electron Beam
Beam Type e-
Beam energy (GeV) 10
Repetition Rate (Hz)
Bunch Charge (nC)
Bunch Length (σ, µm)
Beam Spot size (σ, µm)


Facility staff can work with users to develop beam configurations that match their needs.

Three configurations are currently planned, designed to serve the priority experiments at FACET-II.

  1. Single Bunch, high Ipk: Ipk 50-300kA , β* x,y=0.1-1m
  2. 2-bunch: 1.5/0.5 nC, 30/15 | 20/10 kA, dz=150 μm, β* x,y=5-50cm
  3. Single Bunch, high E, low δE, low aberrations: E=13GeV, σz=100μm, β* x,y=10m

A presentation  at the 2019 Science Workshop provides more information.

The first configuration (single bunch, high I peak) will be developed in the fall of 2021 for experiment time in 2022. The second configuration (2-bunch) will be developed subsequently for experiment time later in 2022.