| Issue Date | 30.06.2023 |
| Closing Date | 31.07.2023 |
| Status | closed |
CALL FOR PROPOSALS
30/ 06/ 2023 – 31/ 07/ 2023
The ELI Beamlines user facility (https://www.eli-beams.eu/en/) invites the scientific community to submit proposals for commissioning the ELBA (Electron BeAmline for fundamental sciece)
ELBA (ELectron BeAmline for fundamental science) is the first all-optical laser electron collider of its kind, being designed on the unique capabilities of the high average power, high repetition rate (30 J, 30 fs, 10 Hz) L3-HAPLS laser. ELBA is designed to enable users to carry out laser-electron interaction experiments approaching χe ≈ 0.18E0[GeV]I1/2[10^21 W/cm^2] ≈ 0.1-1 at high repetition rate (3-10 Hz,100s thousands shots/day).
Based on the scientific interest shown in the ELBA User Workshops 2020, 2021 and 2022, we invite specially qualified users to perform early experiments aimed at achieving high-energy (GeV-class) and stable (better than 10%) electron beams suitable for laser-electron collider experiments (<5 mrad divergence, <5 mrad pointing).
The aim of the call is to:
- Perform user-assisted commissioning experiments, using the capabilities already in operation at ELBA
- Generate stable electron beams with L3-HAPLS
- Increase the future value of experimental capabilities of ELBA beamline for the user community by ensuring that the final development and commissioning steps are completed in collaboration with leading international experts.
- Train ELI Beamlines scientific staff, user office personnel, and support teams together with experienced users in the interactions necessary for efficient user operations.
Instruments available for user-assisted commissioning experiments at ELIMAIA:
- L3-HAPLS laser beam: 10J/30fs in single shot and >1 J (best effort towards 10 J) at 3.3 Hz
- 50:50 Wavefront splitting mirror with a hole
- Aligned and commissioned Off Axis Parabola with 10 meter focal length
- Large vacuum chamber for laser-target interaction (bread board surface ~3mx5m, min pressure ~1×10-5 mbar).
- Target tower for gas target with 3 linear motions and 2 rotations
- 2 permanent magnet dipole electron spectrometers (20cm x 1 T and 30 cm x 1 T)
- Online data acquisition and analysis tools operating at high repetition-rate (up to 3.3 Hz).
- Topview and Nomarski interferometer diagnostics commissioned.
Applicants must be aware that ELI Beamlines will be in a „ramp-up mode“ during the time of the commissioning experiments and this may affect the performance and availability of the individual instruments.
Application submission deadline
31/ 07/ 2023. Expected time from submission to decision is 4 weeks
Application procedure and admittance
On-line application forms are generated from the instrument pages where the updated information on the status and availability of individual instruments and planned commissioning activities is provided. The user will be asked to structure the proposal according to the basic section below:
- detailed scientific description of the project
- technical requirements (laser, diagnostics, etc.)
- information about the applicant team expertise in the field
All applications will be processed by the user administration at ELI Beamlines user.office@eli-beams.eu. Submitted proposals will go through a feasibility assessment headed by the lead scientist of the ELBA beamline and be selected or rejected based on an evaluation against the aims of the call stated above and the feasibility of the proposed experiments. Experiments will be scheduled or rejected on the basis of scientific merit in relation to the aims of the call, technical feasibility, and safety assessment. Results will be communicated to the applicants by the user office of ELI Beamlines.
The lead scientist of the ELBA beamline will assign one suitable researcher of the ELI Beamlines’ team to be the main point of contact for the experiment. The ELI researcher will automatically become a co-proposer (local PI) of the commissioning experiment. The main point of contact will be responsible for communications with the users before, during, and after the experiment, including aspects related to bringing user equipment to ELI Beamlines.
Before gaining access to the premises of ELI Beamlines, users must complete relevant trainings (e.g. general safety, laser safety training). This will be provided by the ELI Beamlines safety team either as on-line training or on-site training as appropriate. A list all relevant safety trainings can be found here.
Useful general information about the ELI Beamlines facility can be found in the ELI Beamlines User-guide.
Relevant information for Applicants
The applicants are encouraged to be familiar with the Data Policy and the User Publication Policy.
User-owned equipment can be included in the experimental. The user shall be familiar and follow the Instructions for bringing user equipment.
Other relevant information can be found in the document Application procedure and admittance.
ELBA laser electron accelerator basic commissioning
ELBA laser electron accelerator basic commissioning has been completed in early June 2023. L3-HAPLS laser pulses were focused by the 10-m focal length OAP both in the full-size and cropped geometry using the mirror with the hole (see Figure below).
The laser can operate from 7:00 am to 7:00 pm, considering both low- (alignment) and high-power modes. Typically, the high power mode is available starting from 10:00 am till the end of the day. Up to 4k shots/day were fired at 10 J on target during the basic commissioning phase, and the highest repetition rate tested was 5 J for 30 minutes at 3.3 Hz (1.8k shots consecutive shots).
Electrons were accelerated up to 100s MeV energy by shooting onto 5 and 10 mm slit nozzles and using a He 99% – N 1% gas mixture. Typical electron beam spectra obtained during the basic commissioning phase with the L3 full-size square beam and the 10-mm nozzle are shown below.
The electron beam spatial pointing and angular divergence are measured by moving out the electron spectrometer (mounted on a remotely controlled linear stage) on a LANEX screen positioned on axis, as shown below for the L3 full-size (left) and cropped geometry (right) configurations. The collimated beams showed a divergence of <5 mrad. The electron pointing stability measured is <20 mrad.
Scope of the user assisted commissioning
The scope of the ELBA user assisted commissioning is to achieve high-energy (GeV-class) and stable (better than 10%) electron beams suitable for laser-electron collider experiments ( >1 GeV energy, <5 mrad divergence, <5 mrad pointing)
The parameters offered for the ELBA user-assisted commissioning are:
- 10-m focal length OAP
- Mirror with the hole for laser beam splitting
- 10-J laser energy on target in single-shot
- >1 J laser energy on target at 3.3 Hz (best effort towards 10 J at 3.3 Hz)
- Gas targets and diagnostics as detailed below
Available target systems
The gas target tower has 5D motion. We can manufacture in-house adapters to hold different types of gas jets. The gas-jets currently available are supersonic slit nozzles with length 4 mm, 5 mm, 6 mm, 8 mm, 10 mm and 12 mm. Users can bring their own target, provided they are compatible in terms of vacuum cleanliness and that they are not clashing with the laser along its propagation axis.
Available metrology
The accelerated electron beams are characterised by an electron spectrometer consisting of two motorised permanent magnetic dipoles, 20 cm x 1 T and 30 cm x 1 T, respectively. LANEX Fast Back scintillator screen captured by using a 12-bit CMOS global shutter camera are used to characterize the electron beam. The system of the LANEX screen coupled to the camera has previously been calibrated on a tuneable medical linear electron accelerator using the same experimental geometry. The FLUKA Monte Carlo simulation package was used to model the calibration and the experimental results. A detailed geometry of the field was calculated using the ESRF’s Radia toolkit, benchmarked with the measured field, and then implemented into a SIMION model to calculate the precise trajectories of the electrons and their coordinates on the LANEX screen for energies from 1 to 100 MeV. The laser-plasma diagnostics are: ultra-short probe beam synchronized with a delay line (from mirror leak), shadowgraph, Nomarski interferometer, and Thomson scattering. Additional user diagnostics can be installed in air and synchronized with the ELBA triggering system. Additional user diagnostics in vacuum are possible if they are compatible with the vacuum cleanliness requirements.
Please use this application form to describe the planned experiment.
We look forward to receiving your proposals!
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