This work presents the design of a compact high-efficiency terahertz source, a collaborative effort between UCLA and RadiaBeam Technologies. The system, driven by a thermionic RF gun, features prebunching elements including alpha-magnet and electromagnetic chicane to effectively compress the long beam generated from the gun. By sending such beam into tapering enhanced waveguide oscillator, we can achieve high efficiency energy extraction in different regimes. This work focuses on the beam dynamics in the beamline prior injection into the undulator. A brief mention of the simulation results for radiation generation is also presented.

Measuring longitudinal beam parameters is key for the operation and development of high-intensity linear accelerators but is notoriously difficult for ion beams at non-relativistic energies. The Bunch Shape Monitor (BSM) is a device used for measuring the longitudinal bunch distribution in a hadron linac. RadiaBeam has developed a BSM prototype with enhanced performance, integrating several key innovations. Firstly, to improve the collection efficiency, we introduced a focusing field between the target wire and the entrance slit. Secondly, we implemented a novel design of the RF deflector to enhance beam linearity. Finally, the design was enriched by incorporating a mechanism that allows moving both the wire and deflector cavity enabling the functionality of transverse profile measurements. In this paper, we present the process of fabricating, assembling, and beam tests of the BSM prototype at the SNS facility.

This work presents the design of a compact high-efficiency terahertz source, a collaborative effort between UCLA and RadiaBeam Technologies. The system, driven by a thermionic RF gun, features prebunching elements including alpha-magnet and electromagnetic chicane to effectively compress the long beam generated from the gun. By sending such beam into tapering enhanced waveguide oscillator, we can achieve high efficiency energy extraction in different regimes. This work focuses on the beam dynamics in the beamline prior injection into the undulator. A brief mention of the simulation results for radiation generation is also presented.

C-band accelerators have been of particular interest in recent years due to their ability to provide high gradients and transport high charge beams for applications such as colliders and medical technologies. New Advancements in high gradient technologies that can suppress the breakdown rate in a particular structure by using distributed coupling, cryogenic cooling, and copper alloys. Previous work has shown each of these separately to significantly improve the maximum gradient. In this work, for the first time, we will combine all three methods in an ultra-high gradient structure and benchmark the difference between Cu and CuAg. The exact same structures were previously tested at room temperature and showed gradients in excess of 200 MeV/m and a 20% improvement in the CuAg version over its pure Cu counterpart [1]. These structures are now tested at 77K simultaneously. They were found to perform similarly due to the presence of significant beam loading. Taking beam loading into account, a maximum achievable gradient of 200 MeV/m achieved for a 1 µs pulse at an input power of 5 MW into each cavity with a breakdown rate of 1e-1 breakdown/pulse/m.

RadiaBeam is designing and manufacturing a fast-ramping alpha magnet is developed for interleaved operation at the Argonne Advanced Photon Source (APS). This interleaving operation requires the alpha magnet to stably complete a 5 s long cycle with a 100 ms ramp-up, 1000 ms nominal field output and a 100 ms ramp-down. A laminated yoke is used to minimize eddy currents, ensure fast field response times and reduce core-loss during operation. The magnetic and mechanical design demonstrating the performance of this 2.75 T/m maximum field gradient alpha magnet within a 10 cm x 14 cm good field region will be presented along with the current fabrication status.

RadiaBeam is developing and manufacturing a 15-mm period, 1.15 T high temperature superconductor undulator using Magnesium Diboride (MgB2) wire to operate in a temperature range of 10 K - 15 K. This temperature range can be achieved by a cryocooler, a simpler and less expensive cryogenic solution compared to a liquid helium approach. As the supported current density, and ultimately the quench behavior of MgB2 wire, is a combined problem of magnetic field, tensile stress, tensile strain and temperature, a multiphysics approach is required. We will present the details of this multiphysics design addressing the magnetic, mechanical and thermal engineering challenges, along with the devices anticipated performance characteristics.

Niobium-tin has been identified as the most promising next-generation superconducting material for accelerator cavities. This is due to the higher critical temperature (Tc = 18 K) of Nb3Sn compared to niobium (TC = 9.2 K), which leads to greatly reduced RF losses in the cavity during 4.5 K operation. This allows two important changes during cavity and cryomodule design. First, the higher Tc leads to negligible BCS losses when operated at 4.5 K, which allows for a higher frequency to be used, translating to significantly smaller cavities and cryomodules. Second, the reduced dissipated power lowers the required cryogenic cooling capacity, meaning that cavities can feasibly be operated on 5-10 W cryocoolers instead of a centralized helium refrigeration plant. These plants and distribution systems are costly and complex, requiring skilled technicians for operation and maintenance. These fundamental changes present an opportunity for a paradigm shift in how low-beta linacs are designed and operated. Fabrication challenges and first coated cavity test results are discussed.

Niobium cavities are key elements in superconducting radiofrequency (SRF) accelerators. Despite increasing worldwide demand, global commercial production capacity is limited to a small number of vendors with virtually no US-based turn-key suppliers. As SRF technology expands across scientific research, industry, and technology sectors, the demand for their production is expected to rise even more in the coming years. Due to the limited supply base and very long delivery times, the US accelerator community is seeking to promote new vendors to enter SRF business capable of rapid iteration of low-volume/high mix R&D cavities. RadiaBeam has been involved in developing niobium fabrication capabilities for several years now, with the objective of understanding the technological challenges and commercial opportunities. In this paper, we present the progress in fabrication process of a single 1.3 GHz TESLA-style niobium cavity at RadiaBeam. This process involves the deep drawing of half cells, machining of weld joints, chemical cleaning, and electron beam welding capabilities.

RadiaBeam is designing and manufacturing a 15-mm period, 1.15 T field superconducting undulator. Realizing these parameters require a small gap, on the order of 5 mm. This small gap imparts a thermal management challenge due to heating from resistive walls, wakefields, upstream dipoles, and particle losses which is challenging to overcome with NbTi or NbSn3 wires without the use of liquid helium. Further, to reduce operating costs and reliance on liquid helium infrastructure, this undulator is designed to run off cryocoolers. In order to provide sufficient thermal overhead for cryocooling capacities, we will utilize Magnesium Diboride (MgB2), a metallic superconductor with a transition temperature at around 39 K. Thermo-mechanical engineering design studies and production plans of our prototype will be presented.

Brookhaven National Laboratory has recently been selected as the site for the Electron-Ion Collider (EIC). The EIC will consist of two intersecting accelerators, one producing an intense beam of electrons, the other a high-energy beam of protons or heavier atomic nuclei, which are steered into head-on collisions. One of the sections of the EIC beamline will require a hadron injection fast kicker system. RadiaBeam is developing GaN-based pulser with ±50 kV voltage amplitude, <4 ns rise and fall times, 40 ns pulse width. In this paper, we discuss the development progress.

Ionization scattering of electron beams with residual gas molecules causes ion trapping in electron rings, both in a collider and electron cooling system. These trapped ions may cause emittance growth, tune shift, halo formation, and coherent coupled bunch instabilities. In order to clear the ions and prevent them from accumulating turn after turn, the gaps in a temporal structure of the beam are typically used. Typically, the gap in the bunch train has a length of a few percent of the ring circumference. In those regions, the extraction electrodes with high pulsed voltages are introduced. In this paper, we present the design consideration and initial test results of the high-voltage pulsed kicker hardware that includes vacuum device and pulsed voltage driver, capable of achieving over 3 kV of deflecting voltage amplitude, rise and fall times of less than 10 ns, 100 ns flat-top duration at 1.4 MHz repetition rate.