Additive Manufacturing of Side-Coupled Cavity Linac Structures from Pure Copper: A First Concept
Compared to conventional manufacturing, additive manufacturing (AM) of radio frequency (RF) cavities has the potential to reduce manufacturing costs and complexity and to enable higher performance. This work evaluates whether normal conducting side-coupled linac structures (SCCL), used worldwide for...
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MDPI AG
2023-12-01
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| Series: | Instruments |
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| Online Access: | https://www.mdpi.com/2410-390X/7/4/56 |
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| author | Michael Mayerhofer Stefan Brenner Ricardo Helm Samira Gruber Elena Lopez Lukas Stepien Gerald Gold Günther Dollinger |
| author_facet | Michael Mayerhofer Stefan Brenner Ricardo Helm Samira Gruber Elena Lopez Lukas Stepien Gerald Gold Günther Dollinger |
| author_sort | Michael Mayerhofer |
| collection | DOAJ |
| description | Compared to conventional manufacturing, additive manufacturing (AM) of radio frequency (RF) cavities has the potential to reduce manufacturing costs and complexity and to enable higher performance. This work evaluates whether normal conducting side-coupled linac structures (SCCL), used worldwide for a wide range of applications, can benefit from AM. A unit cell geometry (SC) optimized for 75 MeV protons was developed. Downskins with small downskin angles <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> were avoided to enable manufacturing by laser powder bed fusion without support structures. SCs with different <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> were printed and post-processed by Hirtisation (R) (an electrochemical process) to minimize surface roughness. The required accuracy for 3 GHz SCCL (medical linacs) is achieved only for <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>α</mi><mo>></mo><msup><mn>45</mn><mo>∘</mo></msup></mrow></semantics></math></inline-formula>. After a material removal of 140 µm due to Hirtisation (R), a quality factor <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>Q</mi><mn>0</mn></msub></semantics></math></inline-formula> of 6650 was achieved. This corresponds to 75% of the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>Q</mi><mn>0</mn></msub></semantics></math></inline-formula> simulated by CST<sup>®</sup>. A 3 GHz SCCL concept consisting of 31 SCs was designed. The effective shunt impedance <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Z</mi><msup><mi>T</mi><mn>2</mn></msup></mrow></semantics></math></inline-formula> simulated by CST corresponds to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>60.13</mn><mspace width="3.33333pt"></mspace><mfrac><mrow><mi mathvariant="normal">M</mi><mi mathvariant="normal">Ω</mi></mrow><mi mathvariant="normal">m</mi></mfrac></mrow></semantics></math></inline-formula> and is comparable to the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Z</mi><msup><mi>T</mi><mn>2</mn></msup></mrow></semantics></math></inline-formula> of SCCL in use. The reduction in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Z</mi><msup><mi>T</mi><mn>2</mn></msup></mrow></semantics></math></inline-formula> expected after Hirtisation (R) can be justified in practice by up to 70% lower manufacturing costs. However, future studies will be conducted to further increase <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>Q</mi><mn>0</mn></msub></semantics></math></inline-formula>. |
| first_indexed | 2024-03-08T20:39:37Z |
| format | Article |
| id | doaj.art-3098ddcd81904f039fefc322abed5b9a |
| institution | Directory Open Access Journal |
| issn | 2410-390X |
| language | English |
| last_indexed | 2024-03-08T20:39:37Z |
| publishDate | 2023-12-01 |
| publisher | MDPI AG |
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| series | Instruments |
| spelling | doaj.art-3098ddcd81904f039fefc322abed5b9a2023-12-22T14:16:26ZengMDPI AGInstruments2410-390X2023-12-01745610.3390/instruments7040056Additive Manufacturing of Side-Coupled Cavity Linac Structures from Pure Copper: A First ConceptMichael Mayerhofer0Stefan Brenner1Ricardo Helm2Samira Gruber3Elena Lopez4Lukas Stepien5Gerald Gold6Günther Dollinger7Institute for Applied Physics and Measurement Technology (LRT2), Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85577 Neubiberg, GermanyInstitute for Applied Physics and Measurement Technology (LRT2), Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85577 Neubiberg, GermanyInstitute for Applied Physics and Measurement Technology (LRT2), Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85577 Neubiberg, GermanyFraunhofer-Institut für Werkstoff- und Strahltechnik IWS, Winterbergstraße 28, 01277 Dresden, GermanyFraunhofer-Institut für Werkstoff- und Strahltechnik IWS, Winterbergstraße 28, 01277 Dresden, GermanyFraunhofer-Institut für Werkstoff- und Strahltechnik IWS, Winterbergstraße 28, 01277 Dresden, GermanyInstitute of Microwaves and Photonics (LHFT), Friedrich-Alexander Universität Erlangen–Nürnberg (FAU), Schloßplatz 4, 91054 Erlangen, GermanyInstitute for Applied Physics and Measurement Technology (LRT2), Universität der Bundeswehr München, Werner-Heisenberg-Weg 39, 85577 Neubiberg, GermanyCompared to conventional manufacturing, additive manufacturing (AM) of radio frequency (RF) cavities has the potential to reduce manufacturing costs and complexity and to enable higher performance. This work evaluates whether normal conducting side-coupled linac structures (SCCL), used worldwide for a wide range of applications, can benefit from AM. A unit cell geometry (SC) optimized for 75 MeV protons was developed. Downskins with small downskin angles <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> were avoided to enable manufacturing by laser powder bed fusion without support structures. SCs with different <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> were printed and post-processed by Hirtisation (R) (an electrochemical process) to minimize surface roughness. The required accuracy for 3 GHz SCCL (medical linacs) is achieved only for <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>α</mi><mo>></mo><msup><mn>45</mn><mo>∘</mo></msup></mrow></semantics></math></inline-formula>. After a material removal of 140 µm due to Hirtisation (R), a quality factor <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>Q</mi><mn>0</mn></msub></semantics></math></inline-formula> of 6650 was achieved. This corresponds to 75% of the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>Q</mi><mn>0</mn></msub></semantics></math></inline-formula> simulated by CST<sup>®</sup>. A 3 GHz SCCL concept consisting of 31 SCs was designed. The effective shunt impedance <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Z</mi><msup><mi>T</mi><mn>2</mn></msup></mrow></semantics></math></inline-formula> simulated by CST corresponds to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mn>60.13</mn><mspace width="3.33333pt"></mspace><mfrac><mrow><mi mathvariant="normal">M</mi><mi mathvariant="normal">Ω</mi></mrow><mi mathvariant="normal">m</mi></mfrac></mrow></semantics></math></inline-formula> and is comparable to the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Z</mi><msup><mi>T</mi><mn>2</mn></msup></mrow></semantics></math></inline-formula> of SCCL in use. The reduction in <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>Z</mi><msup><mi>T</mi><mn>2</mn></msup></mrow></semantics></math></inline-formula> expected after Hirtisation (R) can be justified in practice by up to 70% lower manufacturing costs. However, future studies will be conducted to further increase <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>Q</mi><mn>0</mn></msub></semantics></math></inline-formula>.https://www.mdpi.com/2410-390X/7/4/56additive manufacturingcavitylinac3D printingside-coupled cavity linacpure copper |
| spellingShingle | Michael Mayerhofer Stefan Brenner Ricardo Helm Samira Gruber Elena Lopez Lukas Stepien Gerald Gold Günther Dollinger Additive Manufacturing of Side-Coupled Cavity Linac Structures from Pure Copper: A First Concept Instruments additive manufacturing cavity linac 3D printing side-coupled cavity linac pure copper |
| title | Additive Manufacturing of Side-Coupled Cavity Linac Structures from Pure Copper: A First Concept |
| title_full | Additive Manufacturing of Side-Coupled Cavity Linac Structures from Pure Copper: A First Concept |
| title_fullStr | Additive Manufacturing of Side-Coupled Cavity Linac Structures from Pure Copper: A First Concept |
| title_full_unstemmed | Additive Manufacturing of Side-Coupled Cavity Linac Structures from Pure Copper: A First Concept |
| title_short | Additive Manufacturing of Side-Coupled Cavity Linac Structures from Pure Copper: A First Concept |
| title_sort | additive manufacturing of side coupled cavity linac structures from pure copper a first concept |
| topic | additive manufacturing cavity linac 3D printing side-coupled cavity linac pure copper |
| url | https://www.mdpi.com/2410-390X/7/4/56 |
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