New Beam Line FEBE Enhances Research Opportunities

The Compact Linear Accelerator for Research and Applications (CLARA) is a facility that produces ultra-bright beams of electrons for various kinds of research and applications. Located at STFC Daresbury Laboratory in the UK, CLARA provides a unique opportunity to test different technologies and methods in areas like medical treatment and advanced particle acceleration. With the goal of making this facility even more useful, a new beam line called Full Energy Beam Exploitation (FEBE) is being designed and built. This beam line will allow researchers to access 250 MeV Electron Beams and conduct a wide range of experiments.

#Goals of FEBE

The primary aim of FEBE is to provide a space where researchers can conduct experiments using high-quality electron beams. These beams are essential for many innovative applications, including:

1. Medical Applications: Researchers are looking into using high-energy electrons for therapies that treat cancer.
2. Advanced Accelerator Technology: This includes testing new methods to accelerate particles using lasers and other techniques.
3. Particle Beam Experiments: This area of research focuses on how particle beams can be manipulated and used in various applications.

In light of growing interest from the scientific community, FEBE will include dedicated spaces for experiments, ensuring that researchers can carry out their work without disrupting the main operations of the accelerator.

#Design of the FEBE Beam Line

The FEBE beam line will be constructed parallel to an area originally planned for another project. This new configuration is designed to maximize user access to the electron beam while maintaining safety and stability. The layout incorporates large experiment chambers to accommodate various experiments.

#Key Features of the Design

1. Dedicated Experiment Areas: The design includes a shielded area that allows researchers to access the experimental chambers without shutting down the accelerator. This feature minimizes downtime and ensures stable operation during experiments.

2. Flexible Configuration: The experiment chambers will be designed to host multiple types of experiments, including those that require precise control over the electron beam.

3. High-Power Laser Integration: The beam line will also allow for the combination of electron beams with powerful lasers. This is particularly useful for advanced experiments in particle acceleration and medical therapies.

#Technology Overview

The current version of CLARA can produce electron beams at a maximum energy of 250 MeV. With the installation of new components, researchers will gain access to more powerful electron beams for experimentation. The existing setup includes:

• A photoinjector that generates electron bunches.
• Several acceleration modules that boost the energy of these electron beams.

In the future, researchers plan to upgrade the photoinjector to a new system that can work at a higher repetition rate, allowing for more frequent experiments.

#Experiment Chambers

The FEBE layout features two large experiment chambers, which will be referred to as FEC1 and FEC2. These chambers will allow scientists to perform various experiments, from medical applications to fundamental physics research.

1. FEC1: This chamber will host experiments that may require integration with high-power lasers. The laser light will be combined with the electron beam for unique experimental setups.

2. FEC2: This chamber can be used for follow-up experiments and diagnostics, capturing results from FEC1 or conducting separate experiments.

#Importance of Beam Parameters

For successful experiments, the quality of the electron beams is crucial. Researchers require specific parameters for the electron beams, including:

• High Charge: This refers to the amount of electric charge carried by a bunch of electrons.
• Short Bunch Lengths: The duration of time for which the electron bunch exists is significant for many experiments.
• Small Transverse Size: The size of the electron bunch in the directions perpendicular to its movement must be minimized to improve interaction with targets, like lasers or particle detectors.

By ensuring that these parameters are met, FEBE will support a wide range of experiments and applications.

#Experiment Types and Their Requirements

FEBE aims to support different types of experiments, which will help advance knowledge and technology in various fields.

#Novel Acceleration Techniques

One specific area of interest is research into new forms of particle acceleration. This includes:

1. Plasma Acceleration: Researchers want to understand how to use plasma to accelerate electrons. The electron bunches can either drive the plasma or be further accelerated by lasers.
2. Structure Wakefield Acceleration: This involves using specially designed structures that interact with the electron bunches to enhance their energy.

For these experiments, the ability to create beams with high energy and specific properties is essential.

#Medical Applications

Another important area of focus is the application of electron beams in medical therapies. The goal is to explore how high-energy electrons can be used to treat diseases like cancer through techniques like Very High Electron Energy (VHEE) therapy. This requires the ability to perform precise irradiation of targets.

#Radiation Generation and Particle Beam Experiments

FEBE will facilitate experiments involving the generation of radiation and the manipulation of particle beams. The flexibility of the experiment chambers will allow researchers to test various configurations and setups.

#Beam Dynamics and Simulation

Before the new beam line is fully operational, extensive simulations and tests will be conducted to ensure that the expected beam parameters are achieved.

#Start-to-End Simulations

Simulations will track the behavior of the electron beam from the beginning of its journey through the photoinjector all the way to the point where it exits the FEBE beam line. These simulations are crucial for:

• Verifying that the beam parameters meet the required specifications.
• Optimizing the settings for different configurations needed for various experiments.

By using particle tracking software, the team will analyze how the electron bunches behave under different conditions. This includes looking at aspects like space charge effects, which can distort the beam.

#Diagnostics and Monitoring Systems

To support the various experiments, the FEBE beam line will include advanced diagnostic systems. These systems will help monitor and verify the properties of the electron beams.

#Key Diagnostic Components

1. Beam Position Monitors: These devices ensure that the electron beam is correctly aligned within the experimental setup.

2. Energy Spectrometers: They measure the energy of the electron bunches, allowing researchers to ensure that they are operating at the correct energy levels.

3. Emittance Measurement Systems: These systems will assess the quality of the electron bunches. High-quality beams are crucial for many experiments and applications.

4. Charge Measurement Systems: Accurate measurement of the electron bunch charge is necessary for various experimental setups, especially in those requiring low charge.

#Non-Invasive Diagnostics

The diagnostics system is designed to minimize disruption to the electron beam during measurements. Non-invasive diagnostics will allow researchers to analyze beam properties without affecting the ongoing experiments.

#Laser System and Its Role

The FEBE beam line will also incorporate a high-power laser system. This laser will enable researchers to conduct experiments that require both an electron beam and laser light interacting simultaneously.

#Laser Specifications

The planned laser system will produce pulses with a peak power of 100 TW and a pulse duration of about 25 femtoseconds. Such specifications make the laser ideal for applications in plasma acceleration and other innovative experiments.

#Laser Transport

To bring laser light into the experiment chambers, a carefully designed transport system will be implemented. This system will maintain the integrity of the laser beam and ensure efficient delivery to the interaction points with the electron beam.

#Timing and Synchronization

To ensure successful interactions between the electron beam and the laser, precise timing and synchronization are critical. The design of the FEBE beam line includes a well-coordinated timing system that guarantees both the laser and electron bunches arrive at the interaction points at the correct times.

1. Optical Clock: A stable optical clock will serve as the reference for timing, allowing for high precision synchronization.

2. Synchronization Systems: Several subsystems will work together to ensure that the laser and electron beams operate in harmony.

#Vacuum Management

Maintaining a vacuum environment is crucial for the proper functioning of the FEBE beam line. The design includes systems to manage vacuum conditions while allowing for flexibility in experimenting with different gases when needed.

1. Aperture Restrictions: These will help control the flow of gases, ensuring a clean environment for the electron beam.

2. Monitoring and Adjustment: Continuous monitoring of vacuum conditions will allow for quick adjustments to maintain optimal performance.

#Conclusion

The construction of the Full Energy Beam Exploitation (FEBE) beam line is a significant step toward advancing research capabilities at the CLARA facility. By offering access to 250 MeV electron beams and maintaining a flexible experimental environment, FEBE will enable researchers to explore new technologies and applications in medical treatments, particle acceleration, and fundamental physics research.

As the installation and commissioning of FEBE progress, the scientific community is eagerly anticipating the unique opportunities this new beam line will present. An open call for users is expected once the commissioning phase is complete, paving the way for innovative experiments and groundbreaking discoveries in the years to come.