# First 3D Printed IH-Type Linac Structure—Proof-of-Concept for Additive Manufacturing of Linac RF Cavities

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## Abstract

**:**

## 1. Introduction

## 2. Prototype Design and Concept

#### RF Simulations

## 3. Mechanical Accuracy

## 4. Water Flow

## 5. Preliminary Vacuum Tests

## 6. Printed Material Properties

## 7. Cavity Vacuum Test

#### Further Steps

## 8. Discussion

## Author Contributions

## Funding

## Acknowledgments

## Conflicts of Interest

## References

- Frigola, P.; Agustsson, R.B.; Faillace, L.; Murokh, A.Y.; Ciovati, G.; Clemens, W.A.; Dhakal, P.; Marhauser, F.; Rimmer, R.A.; Spradlin, J.K.; et al. Advance Additive Manufacturing Method for SRF Cavities of Various Geometries. In Proceedings of the 17th International Conference on RF Superconductivity (SRF’15), Whistler, BC, Canada, 13–18 September 2015; pp. 1181–1184. [Google Scholar]
- Jenzer, S.; Alves, M.; Delerue, N.; Gonnin, A.; Grasset, D.; Letellier-Cohen, F.; Mercier, B.; Mistretta, E.; Prevost, C.; Vion, A.; et al. Study of the Suitability of 3D Printing for Ultra-High Vacuum Applications. In Proceedings of the 8th International Particle Accelerator Conference (IPAC’17), Copenhagen, Denmark, 14–19 May 2017; pp. 3356–3358. [Google Scholar] [CrossRef]
- Sattonnay, G.; Alves, M.; Bilgen, S.; Bonnis, J.; Brisset, F.; Gonnin, A.; Grasset, D.; Jenzer, S.; Letellier-Cohen, F.; Mercier, B.; et al. Is it Possible to Use Additive Manufacturing for Accelerator UHV Beam Pipes? In Proceedings of the 10th International Particle Accelerator Conference (IPAC’19), Melbourne, Australia, 19–24 May 2019; pp. 2240–2243. [Google Scholar] [CrossRef]
- Delerue, N.; Carduner, H.; Gerard, R.L.; Jenzer, S.; Manil, P.; Repain, P.; Simar, A. Prospects of Additive Manufacturing for Accelerators. In Proceedings of the 10th International Particle Accelerator Conference (IPAC’19), Melbourne, Australia, 19–24 May 2019; pp. 4118–4120. [Google Scholar] [CrossRef]
- Haehnel, H.; Ratzinger, U. First 3D Printed IH-Type Linac Structure—Proof-of-Concept for Additive Manufacturing of Linac rf Cavities. Presented at the 12th International Particle Accelerator Conference (IPAC’21). Campinas, Brazil, 24–28 May 2021. [Google Scholar] [CrossRef]
- Ratzinger, U. The New High Current Ion Accelerator at GSI and Perspectives for Linac Design Based on H-Mode Cavities. In Proceedings of the 7th European Particle Accelerator Conference (EPAC’00), Vienna, Austria, 26–30 June 2000. [Google Scholar]
- Wolf, C.R.; Beck, F.B.; Franz, L.; Neumaier, V.M. 3D Printing for High Vacuum Applications. In Proceedings of the 22nd International Conference on Cyclotrons and Their Applications (Cyclotrons’19), Cape Town, South Africa, 22–27 September 2019; pp. 317–320. [Google Scholar] [CrossRef]

**Figure 1.**Overview of the cavity geometry and printed parts. (

**a**) 3D printed girder drift tube structure. (

**b**) Cross section of the assembled cavity model.

**Figure 5.**Cross sections of printed KF40 pipe. (

**a**) material homogeneity of the pipe wall (untreated cut); (

**b**) material structure of the pipe wall (etched cut); (

**c**) material homogeneity of the flange overhang (untreated cut); (

**d**) material structure of the flange overhang (etched cut) Courtesy of GSI Darmstadt, pLinac project.

Girder 1 | Girder 2 | ||
---|---|---|---|

${L}_{DT,1}$ | $+70\text{}\mathsf{\mu}\mathrm{m}$ | ${L}_{DT,2}$ | $+20\text{}\mathsf{\mu}\mathrm{m}$ |

${L}_{gap,1-3}$ | $+50\text{}\mathsf{\mu}\mathrm{m}$ | ${L}_{gap,2-4}$ | $+40\text{}\mathsf{\mu}\mathrm{m}$ |

${L}_{DT,3}$ | $+70\text{}\mathsf{\mu}\mathrm{m}$ | ${L}_{DT,4}$ | $+90\text{}\mathsf{\mu}\mathrm{m}$ |

${L}_{gap,3-5}$ | $+30\text{}\mathsf{\mu}\mathrm{m}$ | ||

${L}_{DT,5}$ | $+60\text{}\mathsf{\mu}\mathrm{m}$ |

Scenario | Water Flow |
---|---|

Source | $10.8$ L/min |

6 mm tubing | $7.2$ L/min |

Girder 1 | $4.8$ L/min |

Girder 2 | 5 L/min |

Girder 1&2 parallel | $7.6$ L/min |

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## Share and Cite

**MDPI and ACS Style**

Hähnel, H.; Ratzinger, U. First 3D Printed IH-Type Linac Structure—Proof-of-Concept for Additive Manufacturing of Linac RF Cavities. *Instruments* **2022**, *6*, 9.
https://doi.org/10.3390/instruments6010009

**AMA Style**

Hähnel H, Ratzinger U. First 3D Printed IH-Type Linac Structure—Proof-of-Concept for Additive Manufacturing of Linac RF Cavities. *Instruments*. 2022; 6(1):9.
https://doi.org/10.3390/instruments6010009

**Chicago/Turabian Style**

Hähnel, Hendrik, and Ulrich Ratzinger. 2022. "First 3D Printed IH-Type Linac Structure—Proof-of-Concept for Additive Manufacturing of Linac RF Cavities" *Instruments* 6, no. 1: 9.
https://doi.org/10.3390/instruments6010009