BELLA HTU - Hundred Terawatt Undulator
See also the HTT capability at BELLA described here.
The Berkeley Lab Laser Accelerator (BELLA) Center houses several laser plasma accelerator (LPA) R&D facilities. BeamNetUS users can access the BELLA HTU system offering the capability to accelerate electron beams in plasma targets using a 50-70 TW laser pulse. The HTU beamline also has a basic electron transport line with permanent magnet quadrupoles, electromagnetic quadrupoles, steering magnets, a 4 dipole chicane and a 220 period undulator (1.8 cm period). The Center’s own research in this facility focuses on the research and development of high brightness electron beams for use in future light sources such as a compact free-electron laser.
The laser system consists of a front end that outputs ~2mJ/pulse (uncompressed) at 1kHz, followed by three multi-pass amplifiers that operate at the final 1 Hz repetition rate. The final uncompressed pulse energy is 4 J which is sent to grating-based optical compressors producing compressed pulses which can be 35-40 femtoseconds of ~2.5 J.
Facility bio
Name of Facility: BELLA HTU
Laboratory: Lawrence Berkeley National Laboratory
Address: 1 Cyclotron Road, Berkeley, CA 94720
Point of Contact: Jeroen van Tilborg, Sam Barber
Facility website: Link
Publications list: Link
BELLA is also part of LaserNetUS. BeamNetUS specifically offers awards for research involving the generated electron beam- pure laser research proposals should be directed to LaserNetUS.
| Parameter | Value |
|---|---|
| Beam Type | Electrons |
| Beam Energy | 50-500 MeV* |
| Repetition Rate | 1 Hz |
| Bunch Charge | 0.01-0.2 nC* |
| Bunch Length | 1-10 microns* |
| Beam spot size | 1-5 um at source*, at 0.5-5 mrad divergence* |
| Energy spread | few % to tens-% |
Capabilities
Science specialists: The BELLA center covers the full spectrum of competencies in the field of laser plasma accelerators ranging from theory over experimental laser and plasma methods including diagnostics and plasma source R&D, and experts on simulation tools development.
Available tools:
70 TW beam with synchronized probe beam
Laser diagnostics: wavefront sensors, Grenouille (pulse duration/spectral phase), energy meters, spectrometers
Plasma diagnostics: high resolution wavefront sensor
Electron beam transport line: PMQs, EMQs, steering magnets, chicane, 220 period undulator
Electron beam diagnostics: magnetic spectrometers, beam profile monitors, ICTs
Undulator radiation diagnostics: VIS/UV spectrometer and energy meter, XUV spectrometer
Ideal Experiment
The ideal experiment in a BELLA HTU BeamNetUS campaign takes advantage of the reliability of HTU system and its ability to produce high brightness electron beams in an LPA. With a wide number of controls for electron generation and transport, it offers a unique environment to deploy novel AI/ML based schemes for control, diagnostics and optimization in a complex, advanced accelerator lab. These same capabilities, combined with the electron transport, make it a unique platform to test concepts for radiation generation using LPA generated beams, or for developing diagnostics tailored to characterizing unique and hard to measure quantities of high brightness LPA generated beams like sub-micron emittance and longitudinal phase space.
BELLA HTU general schematic giving sense of controls and diagnostics