2nd Additive Manufacturing for Linear Accelerators Workshop

18 Oct 2026, 18:00 → 20 Oct 2026, 16:50 Europe/Berlin

Geb. 61 "UniCasino" (University of the Bundeswehr Munich)

Michael Mayerhofer (Universität der Bundeswehr München), Hendrik Hähnel (Goethe University Frankfurt, Institute for Applied Physics)

 

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Welcome to AM4Linacs, a workshop dedicated to exploring how additive manufacturing (AM) can support and advance linear particle accelerators. Taking place on October 19 and October 20, 2026, this event brings together researchers, engineers, students, and industry professionals to discuss current advancements, challenges, and opportunities in this exciting field. Whether you’re experienced with AM, just starting to explore its potential, or simply curious, this workshop offers a welcoming space to connect, share ideas, and learn together. We encourage everyone, including students with an interest in AM and linacs, to join the workshop. 

We are looking forward to meeting you!

Michael Mayerhofer & Hendrik Hähnel

Workshop Partners:

 

 

 

Sunday 18 October

18:30 Arrival Dinner Meet-Up (Not included in conference fee)

Informal dinner near the conference venue for participants who already arrived on Sunday. Location to be announced !!Not included in conference fee!!

Monday 19 October

Welcome & Introduction

Conveners: Hendrik Hähnel (Goethe University Frankfurt, Institute for Applied Physics), Michael Mayerhofer (Universität der Bundeswehr München)

Accelerator Session - Monday

1 Additive-Manufactured RACE Cavity R&D, Experimental Validation, and Beyond: Future Roadmap

This talk presents the development history, experimental validation, and future roadmap of the 704.4 MHz RACE Crossbar H-mode (CH) accelerator cavity, fabricated using additive manufacturing (AM) technology. Following successful fabrication, the cavity underwent comprehensive experimental evaluations, including vacuum testing, low-level RF measurements, and high-power conditioning, all of which yielded promising results. Preparations for upcoming beam tests are currently underway. Building on these achievements, the next-generation AM cavity, RACE 2.0, is already under R&D, with all optimizations directed toward achieving high-efficiency acceleration. Overall, these advances demonstrate the strong viability of AM in pioneering high-performance, cost-effective RF structures for future accelerator applications.

Speaker: Chuan Zhang (GSI)

AM4Linacs2026_Zhang.pdf

2 RF Characterization and Beam Measurements with Additively Manufactured Fast Faraday Cups

In the early stages of heavy-ion accelerator chains, sub-nanosecond bunches with velocities between roughly 1% and 20% of the speed of light are produced, demanding longitudinal diagnostics with GHz-scale temporal resolution. Fast Faraday Cups (FFCs) are used to measure the longitudinal charge distribution of such bunches. Their design must simultaneously mitigate pre-field effects and suppress secondary electron emission (SEE) while enabling bunch-by-bunch measurements.
In this talk, we present a tapered, radially coupled FFC, partially manufactured using additive manufacturing (AM), and compare it with an identical version manufactured using conventional techniques. This allows the influence of the manufacturing method on geometric precision and RF properties to be assessed. Finally, we present measurements with ion bunches at the GSI UNILAC in the X2 cave, demonstrating improved SEE suppression and signal-to-noise ratio of the AM-based design while maintaining sufficient temporal resolution for sub-nanosecond bunch diagnostics.

Speaker: Stephan Klaproth (Technische Hochschule Mittelhessen)

AM4Linacs2026_v1.0.pptx

3 Design and Preparation of an Additively Manufactured 1.3 GHz Copper Cavity for High-Gradient Testing

A compact continuous-wave (CW) 1.3 GHz linear accelerator (linac) is being developed as the core component of a pulsed positron annihilation lifetime spectroscopy (PALS) setup. Since conventional manufacturing limits the thermal management required for CW operation of radio-frequency (RF) cavities, pure-copper laser powder bed fusion (PBF-LB/Cu) is used to fabricate monolithic cavities with integrated conformal cooling channels. While PBF-LB/Cu RF structures have shown promising low-power performance, their behavior under high-gradient operation remains largely unexplored. We present an additively manufactured 1.3 GHz single-cell cavity designed for high-gradient tests at the Mainz Energy-Recovering Superconducting Accelerator (MESA) RF system at Johannes Gutenberg University Mainz (JGU). The cavity was optimized with numerical tools such as CST Studio Suite with respect to its RF, thermal and mechanical characteristics. In addition, a detection and analysis framework for monitoring RF breakdown and cavity behavior under high power is presented.

Speaker: Hermann Winter

AM4Linacs2026_Winter_1.3GHz_HPT_Cavity.pdf

AM4Linacs2026_Winter_1.3GHz_HPT_Cavity.pptx

Coffee Break (included)

Accelerator Session - Monday

4 Additively Manufactured High-Frequency H-Mode Cavities for High-Power Accelerators

Additive manufacturing has become a promising avenue for the design of future high power linear accelerators. AM provides incredible opportunities for efficient cooling of H-Mode cavity to enable much higher duty cycle operation despite the compactness of high frequency structures. The design of monolythic or highly integrated cavities from AM copper promises further efficiency improvements while simultaneously reducing cost.
We will report on the recent progress in AM linac cavity design and testing at IAP. In 2025 the first beam test of an additively manufactured pure copper IH-Type structure has been demonstrated at IAP Frankfurt, accelerating a 1.4 MeV proton beam to 2.2 MeV. In the recently launched EU EPITA Project ("Enabling Partnerships for Innovation & Accelerator Technology Advancement"), a fully AM IH-DTL cavity will be produced and beam tested at Cern Linac4 test bench under realistic operation conditions.

Speaker: Hendrik Hähnel (Goethe University Frankfurt, Institute for Applied Physics)

Hähnel 2026-10-19 - AM4Linacs 2026.pdf

Hähnel 2026-10-19 - AM4Linacs 2026.pptx

5 Dielectric Properties of 3D Printed Polymers for RF Applications at 500MHz

To determine the relative permittivity $\epsilon_r$ and the dielectric loss factor $\tan(\delta)$ of 3D printed polymers at 500 MHz a dedicated test cavity was built. When a dielectric material is inserted, the frequency and the quality factor of the cavity change. A comparison of the measured data with simulations yields the values of $\epsilon_r$ and $\tan(\delta)$. This allows the use of these 3D printed polymers in RF applications such as power couplers or RF windows.

Speaker: Philipp Müller (Goethe University Frankfurt, Institute for Applied Physics)

AM4Linacs2026_Philipp_Müller.pdf

AM4Linacs2026_Philipp_Müller.pptx

6 Laser Powder Bed Fusion for the Fabrication of Ultra-High-Vacuum Devices: A Microwave Resonator and Neutral Atom Source

We demonstrate laser powder bed fusion (LPBF) for fabricating ultra-high-vacuum (UHV) components. A microwave resonator for an electron Paul trap required post-processing to reduce surface roughness and achieve suitable quality factors; its morphology and composition were analyzed by SEM, EDX, and profilometry. A calcium evaporation oven was evaluated for thermal performance and vacuum outgassing. Results highlight the potential of LPBF for rapid prototyping of UHV devices.

Speaker: Ivan Hudák (Charles University, Prague)

LPBF for the Fabrication of UHV Devices.pptx

12:00 Lunch (included)

FLAB3D collaboration and AM Lab Tour

7 FLAB3D Collaboration for Additive Manufacturing

Speaker: Eric Jägle

8 AM Lab Tour

Coffee Break (included)

Additive Manufacturing Session - Monday

9 On the importance of surface engineering and conditioning of additively manufactured particle-accelerator components

Metal additive manufacturing (AM), especially laser-based powder bed fusion, enables the fabrication of components with complex geometries and high functional integration, but typically results in relatively rough as-built surfaces. Surface quality is especially critical for particle accelerator components, such as those subjected to radiofrequency, where skin effects become increasingly relevant when associated to uncontrolled surface roughness.
The contribution offers a survey of the main aspects of importance for the design of surfaces of copper parts produced by AM for LInacs. The desired requirements and the critical issues for achieving them in complex components are discussed. Reference to most recent research achievements in this field are made to demonstrate the key role of surface engineering and conditioning in enabling high-performance PBF-LB/M components for Linacs applications.

Speaker: Maurizio Vedani (Politecnico di Milano)

10 Advancements in Multi-Material Powder Bed Fusion of Metals Using a Laser Beam

Producing complex multi-material components using conventional technologies is challenging, time-consuming, and often uneconomical due to additional manufacturing steps and increased costs. Multi-material powder bed fusion of metals using a laser beam (MM PBF-LB/M) opens up new possibilities for processing several materials in a single manufacturing step and can significantly enhance functionality and lightweight potential. The processability of two materials using PBF-LB/M has already been demonstrated for the combination of the copper alloy CW106C (CuCr1Zr) and tool steel 1.2709 (X3NiCoMoTi18-9-5). Defects in the transition zone of the materials, such as pores and cracks, could be influenced and reduced by adjusting process-related parameters. The application for a linear particle accelerator (linac) has been demonstrated. Compared with conventional manufacturing techniques, which often restrict the use of linacs due to the high investment costs, MM PBF-LB/M makes it possible to use 1.2709 for the vacuum flanges and improve structural stability while incorporating a CW106C inner structure for the basic functionality. The elimination of O-rings enabled by the novel CF knife flanges demonstrates the potential of multi-material components for linac applications. Improving the transition zones of already investigated material combinations, as well as processing novel combinations, is the subject of current research and will be discussed in this talk.

Speaker: Constantin Jugert

AM4Linacs_Jugert_final.pdf

11 Improving dimensional accuracy in metal AM through simulation-based distortion compensation

PBF-LB/M is a well-established manufacturing process for high-performance metal components, but achieving tight dimensional tolerances remains challenging. Thermo-mechanical finite element simulations offer a means to predict and compensate for process-induced distortion. We present a simulation approach based on advanced constitutive modelling that does not require geometry-specific model calibration. The method is validated using cantilever reference specimens and subsequently applied to more complex components. The results demonstrate the potential of simulation-based distortion compensation for "first-time-right" additive manufacturing.

Speaker: Stefan Brenner (Universität der Bundeswehr München)

Brenner_AM4Linacs_PDF.pdf

12 Investigation of the influences of process parameters in the selective laser melting process and development of a strategy for the manufacture of test specimens made of CuCr1Zr on a large-scale system with an infrared laser source

Additive manufacturing, in particular the selective laser melting process, is ideally suited to the production of highly complex geometries. There is a clear trend towards increasing component size whilst maintaining high quality and, at the same time, minimising production time. As part of my work, I succeeded in achieving relative densities of over 99.5 % using a large-format system with an infrared laser source, whilst increasing the build rate by 50 %.

Speaker: Adrian Patjek (deutsch)

2026_10_19_LINAC_AM_CuCr1Zr_Patjek_3.pptx

13 Hirtisation – Metal AM post-processing for complex geometries

Hirtisation is a family of chemical/electrochemical post-processing techniques developed for additively manufactured metal parts. Hirtisation aims to remove surface adherent particles, support structures, and reduce surface roughness. Since treatment only requires liquid-part contact complex geometries including hollow chambers and channel systems can be treated in addition to external surfaces. Application showcases such as tuned linac resonance chambers and rocket components are presented.

Speaker: Michael Doppler

2026-10-19_LR PURE_linac workshop.pdf

19:00 Workshop Dinner (included)

Workshop dinner in Munich's historic center. Traditional Bavarian cuisine.

Tuesday 20 October

Additive Manufacturing Session - Tuesday

14 State of the AM Industry - Spotlights and Highlights

This contribution reviews the industrial maturation of additive manufacturing (AM) using data from Wohlers Report 2026 including the Q1 and Q2/2026 Updates, built on survey input from over 1,200 segments across 570 companies. For an audience working on linear accelerators, its value lies less, but for sure also, in overall market size than in what AM is now demonstrating for complex, high-reliability metal hardware built to tight tolerances.

Several materials and process advances stand out. 3D-printed copper cold plates and copper-diamond composites achieving up to 2.5 times the thermal conductivity of pure copper point toward improved heat management for high-heat-load components. Wire-arc AM of titanium alloys and metal AM of gas-turbine parts show complex, high-temperature-tolerant geometries reaching production, with one refinery component cutting costs 42% and lead time from six weeks to under 60 hours. New recovery and recycling routes for strategic metals — including nickel, titanium, tungsten, and niobium, the essential material for superconducting RF cavities — speak directly to the material-sourcing pressures accelerator programs also face.

The talk closes with four industry-wide themes: demand pulled by high-value technical applications, capital discipline, industry consolidation, and growing strategic control over materials, machines, and data — the same supply-chain concerns facing any national lab or accelerator facility sourcing precision, qualification-grade components.

Speaker: Christian Seidel (Wohlers Associates, powered by ASTM International)

Keynote_Seidel_AM4Linacs 2026_v2.pdf

15 Copper Additive Manufacturing: Fundamentals, Applications and Future Potential

Reliably using additively manufactured components in linear accelerators requires consistent quality, even for a single-unit production run. This necessitates a comprehensive understanding of transient defect formation within the component, which is influenced by highly dynamic process phenomena. High-speed X-ray imaging provides the necessary spatial and temporal resolution to directly observe melt pool and keyhole dynamics during laser powder bed fusion (PBF-LB). This allows for the identification of relationships between processing conditions and keyhole behavior, porosity and spatter formation. Thus, it supports developing robust process windows and process-structure-property relationships. This talk will discuss how these fundamental insights can be applied to laser processing copper and its alloys as important materials for thermally and electrically demanding accelerator components. Finally, the presentation will outline the potential of complementary laser powder- and wire-fed directed energy deposition routes for manufacturing, repairing, and qualifying larger or functionally integrated components.

Speaker: Kamal Miah (BTU Cottbus-Senftenberg, Füge- und Schweißtechnik)

16 Ultrasonic Additive Manufacturing at UChicago

An overview of ultrasonic additive manufacturing (UAM) and its potential applications in accelerators with updates on developmental efforts at the University of Chicago Engineering and Technical Support Group (ETSG). ETSG involvement with the technology has unfortunately been limited thus far by funding, so conversations with attendees about potential uses or collaboration opportunities would be welcomed.

Speaker: John Brandt (University of Chicago)

UAM at UChicago_20261020.pptx

17 Post-processing of complex RFQ samples fabricated by PBF-LB

Laser Powder Bed Fusion (PBF-LB) enables fabrication of complex LINAC components, such as radiofrequency quadrupoles (RFQs). However, the high surface roughness of as-built parts can reduce RF conductivity, breakdown resistance, and vacuum performance.
This work investigates mechanical and chemical treatments to improve the surface finish of RFQ samples produced by PBF-LB, focusing on the hard-to-access vane tip region. Treatments were applied sequentially, with characterization after each step to study the evolution of surface characteristics.

Speaker: Tobia Romano (Politecnico di Milano)

Coffee Break (included)

Accelerator Session - Tuesday

18 Printed H - Cavity Options Above 100 MeV/u

Beam dynamics and cavity design studies have been performed to investigate H - type structures in the frequency range from 500 to 1000 MHz. Comparisons in RF efficiency and structure complexity with established DTL's in that velocity range are shown.

Speaker: Ulrich Ratzinger (Goethe - Universität Frankfurt)

Workshop-Talk-26-10-14.pdf

19 Additive Manufacturing of Accelerator Structures — Opportunities and Challenges from an Industrial Perspective

The manufacturing of normal-conducting accelerator structures relies on a long supply and manufacturing chain, in which time and cost drivers are sometimes hidden within subsystems. Additive manufacturing offers the opportunity to drastically simplify manufacturing processes and thus generate economic value. However, this requires a fundamental reevaluation of existing designs rather than merely adapting them in part to the capabilities of additive manufacturing. Several critical issues drawn from industrial manufacturing experience will be examined, and additive manufacturing solutions will be presented.

Speaker: Peter vom Stein (RI Research Instruments GmbH)

261020 RI Accelrator Stutures.pdf

20 Application of Additive Manufacturing in Beam Diagnostics and Radiation Shielding

Additive manufacturing provides a fast, cost-effective, and flexible method for developing customized camera mounts that can be precisely adapted to their designated positions, both inside and outside of Linac cavities. Besides beam characterization, CMOS cameras at our institute are also applied to acquire multipacting and cavity glowing effects during conditioning. In this case, due to the radiation produced by a cavity in operation, the cameras need to be shielded for improving the image quality.
For this purpose, a shielding enclosure was fabricated using tungsten-filled filament (Prusament, PETG Tungsten 75 %). The shielding performance was evaluated by comparing images recorded with the shielded camera to those obtained with an unshielded camera under equivalent conditions.

Speaker: Leonie Bauer (Goethe University Frankfurt, Institute for Applied Physics)

AM4LINACS26_Bauer.pdf

12:00 Lunch (included)

Accelerator Session - Tuesday

21 Rapid design-print-test cycles for additively manufactured accelerator cavities

Linear accelerator fabrication has remained largely unchanged for decades: components are precision-machined, assembled, and tuned through many iterative cycles. This model is well suited to scientific facilities, but less so to industrial applications, where rapid iteration, customization, and cost control are essential.

Additively manufactured accelerator structures may offer a better fit for industrial deployment, and Tachyon Industrial plans to make them a core element of its approach. Our first accelerator targets heavy-ion single-event-effects testing, a low-current, moderate-energy application. These relatively modest demands on the accelerating structures create room to experiment with minimizing post-processing and intentionally matching build quality to application requirements rather than pursuing unnecessary precision.

We will present our initial work on a rapid cavity design-print-test cycle, including the design choices, manufacturing tradeoffs, and evaluation process that inform our path toward lower-cost, customizable industrial accelerators.

Speaker: Niv Levy (Tachyon Industrial)

AM4Linacs2026_Levy_slides.pdf

22 3D-Printed 4-Rod RFQ Including Gyroid Cooling Structures

In high-duty-cycle and CW operation, 4-rod RFQs are limited mainly by heat removal from stems and the tuning plates. Local heating causes deformation, detuning and a degraded field distribution. Conventionally manufactured cooling channels are limited in their form and position by the manufacturing process.

This talk presents the development of a 4-rod RFQ prototype made by laser powder bed fusion (L-PBF) from pure copper and a copper alloy (CuCrZr). The conventional cooling channels are partly replaced by gyroid lattice structures inside the components. Gyroids offer a very large heat-exchange surface, are self-supporting during printing and leave the RF surfaces intact.

Speaker: Julius-Stephan Storch (Goethe Universität, Frankfurt)

AM4LINAC_2026_Storch.pptx

23 Compact Ion Accelerators at High Frequencies – Use of Additive Manufacturing Processes

Metal additive manufacturing offers new opportunities for compact, normal-conducting linear accelerator components. This work investigates additively manufactured IH-type drift-tube structures, focusing on fabrication tolerances, post-processing, RF performance, and thermal management. Electromagnetic simulations and low-level RF measurements show that small geometric deviations can shifts in resonant frequency and changes in effective shunt impedance. Conformal cooling channels were then optimized through electromagnetic, thermal, and fluid-dynamic simulations and validated experimentally. The final design of the cooling channels achieved temperature and stable hydraulic behaviour under experimental boundary conditions, while also showing that the design on higher thermal loads shows better performance then some traditionally manufactured accelerator components. These results demonstrate that additive manufacturing can provide functional advantages beyond simplified production, with higher complexity and good performance under higher loads.

Speaker: Benjamin Dedic (Goethe Universität Frankfurt)

14:15 Coffee Break (included)

Accelerator Session - Tuesday

24 Challenges and Opportunities for 3D Printed RF Gun Cavities

High-gradient RF-photo-injectors offer outstanding electron-beam quality and properties, and are therefore utilized as drivers for X-ray free-electron lasers (XFELs), ultra-fast electron diffraction (UED), and other applications requiring short bunches with low emittance. DESY, with its sites in Hamburg and Zeuthen, has several decades of experience in developing and operating these particle sources. In particular, the free-electron lasers European XFEL and FLASH, as well as the small(er) scale facilities PITZ, ARES, and REGAE are driven by RF-photo-guns and rely on the unique beam parameters provided.

New manufacturing concepts based on additive manufacturing (AM) could offer ways to further improve the performance and expand the parameter space provided by these electron sources. For example, even higher gradients — and thus even smaller emittances — and an increase in repetition rate are highly desirable. However, both are challenging in terms of thermal load, which could be solved by AM approaches. At the same time, the cavity itself requires precise machining with tight tolerances and smooth surface quality to withstand the large fields and suppress dark current emission, which might be a challenge worth to address for the current state of the additive-manufacturing-art.

Speaker: Benno Zeitler (DESY)

20261020_AM4Linacs_reduced.pdf

25 Development of an Additively Manufactured 1.3 GHz Cavity for PLEPS

A compact 1.3 GHz linear particle accelerator (linac) is currently under development to extend the range of applications of the pulsed low-energy positron system (PLEPS) located at the Forschungs-Neutronenquelle Heinz Maier-Leibnitz (FRM II). The linac is based on a side-coupled radio-frequency (RF) cavity (SCC) geometry to reduce footprint and power consumption. However, conventional fabrication of SCCs faces significant thermal and mechanical limitations which influence the linac's performance. Laser Powder Bed Fusion (L-PBF) has already demonstrated the ability to produce monolithic pure copper cavities, enabling a complex integrated cooling system and reducing manufacturing time and costs. We aim to transfer this potential to the required 1.3 GHz SCC, making this the first fully additively manufactured SCC developed for a real experimental application. This work presents the first fundamental design of the required SCC geometry. The electromagnetic field distribution was optimized using simulation tools such as CST Studio. Beam dynamics studies conducted using TraceWin code demonstrate capabilities of the proposed linac concept.

Speaker: Vitus Michael Schuster (Universität der Bundeswehr München (LRT2))

26 Additive Manufacturing and Conjugate Heat Transfer Analysis of a Gyroid Cooling Plate

This presentation explores the design, additive manufacturing and thermal performance of a CuCr1Zr cooling plate with an internal gyroid structure for electronic components in particle accelerator systems. The manufacturing process combines laser powder bed fusion with subsequent heat treatment and machining of functional surfaces. Steady-state and transient conjugate heat transfer (CHT) simulations in Ansys Discovery couple heat conduction in the solid with coolant flow and heat transfer. Temperature distributions, flow behaviour and pressure drop are compared with a reference plate featuring conventional cooling channels under identical operating conditions. The results indicate lower peak temperatures, particularly during transient loading, accompanied by increased pressure drop, highlighting the trade-off between thermal performance and hydraulic resistance.

Speaker: Ramy Cherif (G.S.I)

Discussion