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Publications (10 of 75) Show all publications
Rossetti, M., Mathiyalagan, S., Björklund, S., Sowers, S. & Joshi, S. V. (2023). Advanced diamond-reinforced metal matrix composite (DMMC) coatings via HVAF process: Effect of particle size and nozzle characteristics on tribological properties. Ceramics International, 49(11 Part A), 17838-17850
Open this publication in new window or tab >>Advanced diamond-reinforced metal matrix composite (DMMC) coatings via HVAF process: Effect of particle size and nozzle characteristics on tribological properties
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2023 (English)In: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956, Vol. 49, no 11 Part A, p. 17838-17850Article in journal (Refereed) Published
Abstract [en]

High-velocity air fuel (HVAF) spraying is a versatile and cost-effective platform to fabricate wear resistant coatings. In this work, deposition of Nickel–Phosphorus cladded diamond feedstock is explored as a greener alternative to realize highly wear resistant large-area coatings. To the best of authors knowledge. this is the first study that has utilized HVAF technique for developing wear resistant Ni–P coatings reinforced with diamond (NCD). This work also aims to understand the effect of particle size by using coarse (20–30 μm) and fine NCD (10–15 μm) particles as feedstock. The importance of utilizing appropriate processing conditions was also highlighted by using two different nozzle configurations, for which the two powder particle sizes exhibited considerable differences in terms of microstructure, phase characteristics and mechanical properties. Further, the effect of annealing on the above coating characteristics was also examined, and it is shown that optimal spraying conditions can preclude the need for post-treatment. Furthermore, the as-deposited and annealed coatings were subjected to sliding wear tests to assess their tribological performance. Post-wear analysis performed on worn surfaces revealed the associated wear mechanisms. The results ensuing from this work lay the foundation for realizing new generation of HVAF sprayed wear resistant Ni–P/diamond composite coatings for diverse applications.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
composite coatings, DMMC, Microstructure, Tribology
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-20130 (URN)10.1016/j.ceramint.2023.02.150 (DOI)000989038200001 ()2-s2.0-85150391038 (Scopus ID)
Funder
Swedish Energy Agency, P46393-1
Available from: 2023-06-28 Created: 2023-06-28 Last updated: 2024-01-04Bibliographically approved
Bellippady, M., Florent, M., Björklund, S., Li, X. H., Robert, F., Kjellman, B., . . . Markocsan, N. (2023). Characteristics and performance of suspension plasma sprayed thermal barrier coatings on additively manufactured superalloy substrates. Surface and Coatings Technology, 472, Article ID 129926.
Open this publication in new window or tab >>Characteristics and performance of suspension plasma sprayed thermal barrier coatings on additively manufactured superalloy substrates
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2023 (English)In: Surface and Coatings Technology, ISSN 0257-8972, Vol. 472, article id 129926Article in journal (Refereed) Published
Abstract [en]

The complex-shaped hot-section parts of new-generation turbine engines demand unique design solutions. Additive Manufacturing (AM) is an emergent production method that can produce metallic parts with complex geometries and minimal material wastage. In this work, the characteristics and performance behavior of Thermal Barrier Coatings (TBCs) deposited on forged and AM-built HAYNES®282® superalloy substrates were studied and compared. The bond coats were produced by High-Velocity Air-Fuel (HVAF) spraying using NiCoCrAlY powder feedstock and TBC top-coats by Suspension Plasma Spraying (SPS) using water- and ethanol-based suspensions of Yttria-Stabilized Zirconia (YSZ). The microstructural features, adhesion, Thermal Cycling Fatigue (TCF) lifetime, and thermal shock lifetimes of the TBCs were comprehensively investigated. The results showed that the deposition of bond coats reduced the roughness and asperities of the AM-built substrates. Depending on the type of suspension used and the spray parameters employed, the TBCs exhibited vertically cracked and columnar microstructures. However, no significant differences in TCF and thermal shock lifetimes of TBCs on AM and forged substrates were observed. It is demonstrated that TBC systems can be produced on AM-built metallic substrates, and the resulting TBCs can have similar microstructures and properties as TBCs deposited on conventional substrates.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Additive manufacturing, Thermal barrier coatings, Ni-based superalloys, Microstructural characterization, Thermal cycling, Thermal chock
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-20674 (URN)10.1016/j.surfcoat.2023.129926 (DOI)001064871700001 ()2-s2.0-85168408972 (Scopus ID)
Note

CC BY 4.0

Available from: 2023-12-29 Created: 2023-12-29 Last updated: 2023-12-29
Mulone, A., Mahade, S., Björklund, S., Lundström, D., Kjellman, B., Joshi, S. V. & Klement, U. (2023). Development of yttria-stabilized zirconia and graphene coatings obtained by suspension plasma spraying: Thermal stability and influence on mechanical properties. Ceramics International, 49(6), 9000-9009
Open this publication in new window or tab >>Development of yttria-stabilized zirconia and graphene coatings obtained by suspension plasma spraying: Thermal stability and influence on mechanical properties
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2023 (English)In: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956, Vol. 49, no 6, p. 9000-9009Article in journal (Refereed) Published
Abstract [en]

This study investigated the feasibility of depositing graphene nanoplatelet (GNP)-reinforced yttria-stabilized zirconia (YSZ) composite coatings. The coatings were deposited from an ethanol-based mixed YSZ and GNP suspension using suspension plasma spraying (SPS). Raman spectroscopy confirmed the presence of GNPs in the YSZ matrix, and scanning electron microscopy (SEM) analysis revealed a desired columnar microstructure with GNPs distributed predominantly in the inter-columnar spacing of the YSZ matrix. The as-deposited YSZ-GNP coatings were subjected to different isothermal treatments—400, 500, and 600 °C for 8 h—to study the thermal stability of the GNPs in the composite coatings. Raman analysis showed the retention of GNPs in specimens exposed to temperatures up to 500 °C, although the defect concentration in the graphitic structure increased with increasing temperature. Only a marginal effect on the mechanical properties (i.e., hardness and fracture toughness) was observed for the isothermally treated coatings. 

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Composite coatings; Fracture toughness; Graphene; Isotherms; Plasma jets; Plasma spraying; Plasma stability; Scanning electron microscopy; Thermodynamic stability; Yttria stabilized zirconia; Yttrium oxide; Electron microscopy analysis; Graphene coatings; Graphene nanoplatelets; Raman; Suspension plasma spraying; Suspension plasma sprays; Yttria stabilized zirconia coatings; Yttria-stabilized-zirconia; Zirconia composite coatings; Zirconia matrix; Microstructure
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-19433 (URN)10.1016/j.ceramint.2022.11.055 (DOI)000965427300001 ()2-s2.0-85141532957 (Scopus ID)
Note

This is an open access article under the CC BY 4.0 license.

The authors would like to acknowledge the national Strategic Innovation Programme for graphene, SIO Grafen, for the financial support received. The programme is supported by the Swedish government agencies Vinnova (Sweden’s Innovation Agency), the Swedish Energy Agency and the Swedish Research Council Formas. The project grant nr.Is Dnr 2018–03315

Available from: 2023-01-23 Created: 2023-01-23 Last updated: 2024-01-05Bibliographically approved
Fefekos, A. G., Gupta, M. K., Mahade, S., Björklund, S. & Joshi, S. V. (2023). Effect of spray angle and substrate material on formation mechanisms and properties of HVAF sprayed coatings. Surface & Coatings Technology, 452, Article ID 129115.
Open this publication in new window or tab >>Effect of spray angle and substrate material on formation mechanisms and properties of HVAF sprayed coatings
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2023 (English)In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 452, article id 129115Article in journal (Refereed) Published
Abstract [en]

Thermally sprayed coatings are often used to enhance the surface properties (wear resistance, corrosion resistance, etc.) of engineering components in order to extend their performance and service lifetime. Typically, the industrial components to be coated possess complex geometries and are fabricated using different materials, which can influence the deposited coating’s microstructure and performance. High-velocity air fuel (HVAF) process is a relatively new thermal spray processing technique that has shown tremendous potential to deposit high performance coatings for durable industrial components. However, no detailed studies have been reported on HVAF sprayed coating formation mechanisms so far in relation to the spray angle and substrate properties, and the influence of coating material on the above. The objective of this work was to study the influence of spray angles and substrate materials on splat characteristics, coating microstructure evolution, properties and performance for two distinct coating materials. In this study, one cermet (WC-CoCr) and one metallic (Inconel 625) feedstock were deposited onto three different substrates (aluminium alloy, carbon steel and Hastelloy-X) utilising different spray angles (40°, 60° and 90°). The coating evolution was analysed utilising SEM/EDS, image analysis, and micro-indentation. To determine the tribological performance, coatings were subjected to dry sliding wear test utilising alumina ball as counter surface and specific wear rates were obtained. The results showed that initial splat characteristics were substantially altered on changing the substrate and the spray angle. However, the final coating properties were not affected significantly even though the deposition rate was reduced significantly at lower spray angle, suggesting the versatility of the HVAF process. 

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Air; Alumina; Coated materials; Corrosion resistance; Corrosion resistant coatings; Deposition rates; Metal substrates; Microstructure; Sprayed coatings; Tribology; Wear of materials; Wear resistance; Coating formation; Dry sliding wear; Dry sliding wear testing; Formation mechanism; High velocity air fuel spraying; High velocity air fuels; Splat characteristic; Spray angle; Substrate material; Wear-testing; Aluminum oxide
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-19503 (URN)10.1016/j.surfcoat.2022.129115 (DOI)2-s2.0-85143850042 (Scopus ID)
Funder
Knowledge Foundation, 20170198
Note

CC-BY 4.0

Available from: 2022-12-29 Created: 2022-12-29 Last updated: 2024-01-05
Owoseni, T. A., Ciudad de Lara, I., Mathiyalagan, S., Björklund, S. & Joshi, S. V. (2023). Microstructure and Tribological Performance of HVAF-Sprayed Ti-6Al-4V Coatings. Coatings, 13(11), 1-15
Open this publication in new window or tab >>Microstructure and Tribological Performance of HVAF-Sprayed Ti-6Al-4V Coatings
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2023 (English)In: Coatings, ISSN 2079-6412, Vol. 13, no 11, p. 1-15Article in journal (Refereed) Published
Abstract [en]

Ti-6Al-4V is a widely used titanium alloy in aviation and bio/chemical applications for its attractive mechanical and corrosion resistance properties. The use of Ti-6Al-4V as a coating for repair purposes through thermal spray techniques provides a unique productivity opportunity. A repair coating must be dense to provide the required in-service functionalities, such as resistance to wear. The High Velocity Air Fuel (HVAF) thermal spray technique deposits dense coatings with reduced concern for oxide inclusions. This work presents an investigation of the microstructure, dry sliding, and solid particle erosive wear performance of four different coatings engineered through the configuration of the nozzle of an HVAF spray gun, based on the length of the nozzle and the size of the nozzle exit. A long nozzle length and wide nozzle exit mean increased inflight dwell time and reduced average inflight temperature for the sprayed particles, respectively—a reversed configuration means the opposite. The tested coatings showed a porosity of less than 2%. The sliding and erosion wear performance of the densest of the coatings compares to that of the bulk material tested under the same conditions. Electron microscopy was used to investigate the driving mechanisms for the performance of the respective coatings. The implications of the results are discussed for the potential adoption of HVAF-sprayed coatings in metal component repair.

Place, publisher, year, edition, pages
MDPI, 2023
Keywords
Ti-6Al-4V; HVAF thermal spray; sliding wear; erosion wear; microstructure
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-21055 (URN)10.3390/coatings13111952 (DOI)001107849600001 ()2-s2.0-85177861893 (Scopus ID)
Funder
Vinnova, 2020-02997
Note

CC BY 4.0

This article belongs to the Special Issue Mechanical Properties and Tribological Behavior of Alloy/Coatings

Available from: 2023-12-27 Created: 2023-12-27 Last updated: 2024-01-26
Meghwal, A., Anupam, A., Boschen, M., Singh, S., Björklund, S., Joshi, S. V., . . . Ang, A. S. (2023). Novel Al2CoCrFeNi high-entropy alloy coating produced using suspension high velocity air fuel (SHVAF) spraying. Intermetallics, 163, 1-4, Article ID 108057.
Open this publication in new window or tab >>Novel Al2CoCrFeNi high-entropy alloy coating produced using suspension high velocity air fuel (SHVAF) spraying
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2023 (English)In: Intermetallics, ISSN 0966-9795, Vol. 163, p. 1-4, article id 108057Article in journal (Refereed) Epub ahead of print
Abstract [en]

Metallic coatings of Al2CoCrFeNi high entropy alloy (HEA) were deposited using the suspension high velocity air fuel spray (SHVAF) process, towards exploring its viability as a bond coat in thermal barrier coatings. The relatively high Al content promoted a BCC + B2 phase-dominated coating structure, leading to enhanced mechanical properties. The oxidized microstructure exhibited a protective Al2O3 layer with characteristics comparable to conventional bond coat alloys. 

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
High entropy alloys (HEAs), Suspension, High-velocity air fuel (HVAF), Oxidation
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-20882 (URN)10.1016/j.intermet.2023.108057 (DOI)2-s2.0-85171150205 (Scopus ID)
Note

CC BY 4.0

Available from: 2023-12-28 Created: 2023-12-28 Last updated: 2023-12-28
Frost, R. J., Thomas, C. A., Elfman, M., Johansson, R., Hartl, M., Kocevar, H., . . . Björklund, S. (2023). Preliminary results from a study of luminescent materials: For application in the beam imaging system at the ESS. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 540, 227-233
Open this publication in new window or tab >>Preliminary results from a study of luminescent materials: For application in the beam imaging system at the ESS
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2023 (English)In: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 540, p. 227-233Article in journal (Refereed) Published
Abstract [en]

As part of the development of the beam imaging system at the European Spallation Source, luminescent screens have been fabricated by the flame spraying of scintillating materials onto stainless steel backings. A total of seven screens were produced, three of chromia alumina (Al2O3:Cr), two of YAG (Y3Al5O12:Ce) and two of a 50/50 mix of these. The properties of these screens under proton irradiation were evaluated using a2.55 MeV proton beam at currents of up to 10 μA. Irradiation times were up to 25 h per sample, during which luminescence-, spectrographic-, thermal- and current-data was sampled at a rate of 1 Hz. Preliminary results of these measurements are reported here; with a quantitative analysis presented for one of the chromia alumina screens and a qualitative comparison of all three material types. The luminescent yield for chromia alumina was determined to be around 2000 photons/MeV for a virgin screen, and was found to drop to 1.5% after 167 mC of proton irradiation. A recovery of the luminescence of chromia alumina to >60% was observed after beam current was reduced for an 8 h period. Observations indicate that the YAG and mixed composition screens retain higher luminescence than the chromia alumina even at temperatures of over 200 ◦C. It is indicated that the luminescence from YAG feeds the R-lines of chromia alumina in the mixed composition screens. 

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
ESS, Beam imaging, Luminescent screens, Chromia alumina, YAG
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-20300 (URN)10.1016/j.nimb.2023.04.015 (DOI)001001818100001 ()2-s2.0-85156268474 (Scopus ID)
Note

CC BY 4.0

Available from: 2023-07-04 Created: 2023-07-04 Last updated: 2024-01-12Bibliographically approved
Mathiyalagan, S., Rossetti, M., Björklund, S., Sowers, S., Dumm, T., Kim, C. & Joshi, S. V. (2022). High velocity air fuel (HVAF) spraying of nickel phosphorus-coated cubic-boron nitride powders for realizing high-performance tribological coatings. Journal of Materials Research and Technology, 18, 59-74
Open this publication in new window or tab >>High velocity air fuel (HVAF) spraying of nickel phosphorus-coated cubic-boron nitride powders for realizing high-performance tribological coatings
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2022 (English)In: Journal of Materials Research and Technology, ISSN 2238-7854, Vol. 18, p. 59-74Article in journal (Refereed) Published
Abstract [en]

High velocity air fuel (HVAF) spraying is an emergent thermal spray process, which is used in this work to realize high-performance large area tribological coatings of nickel-phosphorus cladded cubic-boron nitride (c-BN) particles. To the best of authors’ knowledge, this is the first time that HVAF has been utilized for developing Ni–P coatings reinforced with c-BN (NBN). The importance of appropriate processing was highlighted by utilizing two different nozzle configurations, for which microstructure, phase analysis and hardness results demonstrates considerable differences. Furthermore, the coatings were subjected to sliding wear tests to assess their friction and wear characteristics. Post-wear SEM analysis reveals the associated wear mechanisms. Effect of annealing on tribological performance of NBN coatings was also examined, and it is shown that optimal processing can preclude the need for post-treatment. Results ensuing from this work lay the foundation for new generation of HVAF-sprayed wear resistant metal/c-BN composite coatings for diverse applications. © 2022 The Author(s)

Place, publisher, year, edition, pages
Elsevier Editora Ltda, 2022
Keywords
Air; Composite coatings; III-V semiconductors; Nickel coatings; Sprayed coatings; Tribology; Wear of materials; Composites coating; High velocity air fuels; Ni-P coating; Nickel phosphorus; Nitride particles; Nitride powders; Nozzle configuration; Performance; Thermal spray process; Tribological coatings; Microstructure
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-18290 (URN)10.1016/j.jmrt.2022.02.058 (DOI)2-s2.0-85126770865 (Scopus ID)
Funder
Swedish Energy Agency, P46393-1Knowledge Foundation, projectHiPerCOAT (Dnr. 20180197)
Note

The authors thank NUCoP project (Energimyndigheten, Sweden, Dnr. 2018e003191, Project nr. P46393-1 and the knowledge foundation, Sweden, for its financial support to projectHiPerCOAT (Dnr. 20180197) for their financial support. Theauthors also thank Mr. Magnus Sandberg, University West, forassisting in spraying the coatings and Mr. Mats Hogstr € om, €University West, for performing heat treatment.

Available from: 2022-04-14 Created: 2022-04-14 Last updated: 2022-04-14
Löbel, M., Lindner, T., Mehner, T., Rymer, L.-M., Björklund, S., Joshi, S. V. & Lampke, T. (2022). Microstructure and Corrosion Properties of AlCrFeCoNi High-Entropy Alloy Coatings Prepared by HVAF and HVOF. Journal of thermal spray technology (Print) (1-2), 247-255
Open this publication in new window or tab >>Microstructure and Corrosion Properties of AlCrFeCoNi High-Entropy Alloy Coatings Prepared by HVAF and HVOF
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2022 (English)In: Journal of thermal spray technology (Print), ISSN 1059-9630, E-ISSN 1544-1016, no 1-2, p. 247-255Article in journal (Refereed) Published
Abstract [en]

High-entropy alloys (HEAs) represent an innovative development approach for new alloy systems. These materials have been found to yield promising properties, such as high strength in combination with sufficient ductility as well as high wear and corrosion resistance. Especially for alloys with a body-centered cubic (bcc) structure, advantageous surface properties have been revealed. However, typical HEA systems contain high contents of expensive or scarce elements. Consequently, applying them as coatings where their use is limited to the surface represents an exciting pathway enabling economical exploitation of their superior properties. Nevertheless, processing conditions strongly influence the resulting microstructure and phase formation, which in turn has a considerable effect on the functional properties of HEAs. In the presented study, microstructural differences between high-velocity oxygen fuel (HVOF) and high-velocity air fuel (HVAF) sprayed coatings of the alloy AlCrFeCoNi are investigated. A metastable bcc structure is formed in both coating processes. Precipitation reactions are suppressed by the rapid solidification during atomization and by the relatively low thermal input during spraying. The coating resistance to corrosive media was investigated in detail, and an improved passivation behavior was observed in the HVAF coatings. 

Place, publisher, year, edition, pages
Springer, 2022
Keywords
Air; Aluminum alloys; Aluminum corrosion; Chromium alloys; Cobalt alloys; Corrosion resistance; Corrosive effects; Crystal structure; Entropy; High-entropy alloys; HVOF thermal spraying; Iron alloys; Microstructure; Rapid solidification; Wear resistance, Body-centered cubic (bcc) structure; Development approach; Functional properties; High velocity air fuels; High velocity oxygen fuel(HVOF); Precipitation reaction; Processing condition; Wear and corrosion resistance, Sprayed coatings
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-17471 (URN)10.1007/s11666-021-01255-2 (DOI)000694622600002 ()2-s2.0-85114623447 (Scopus ID)
Note

cited By 0

Available from: 2021-09-20 Created: 2021-09-20 Last updated: 2023-01-25Bibliographically approved
Adli, E., Gjersdal, H., Sjøbæk, K. N., Christoforo, G., Fackelman, E. D., Røhne, O. M., . . . Björklund, S. (2022). Progress Of The Ess Proton Beam Imaging Systems. In: LINAC2022: . Paper presented at 31st International Linear Accelerator Conference LINAC2022, Liverpool, United Kingdom (pp. 395-398). ACoW Publishing
Open this publication in new window or tab >>Progress Of The Ess Proton Beam Imaging Systems
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2022 (English)In: LINAC2022, ACoW Publishing , 2022, p. 395-398Conference paper, Oral presentation with published abstract (Refereed)
Abstract [en]

The ESS Target Proton Beam Imaging Systems has the objective to image the 5 MW ESS proton beam as it entersthe spallation target. The imaging systems has to operate in a harsh radiation environment, leading to a number of challenges : development of radiation hard photon sources, long and aperture-restricted optical paths and fast electronics required to provide rapid information in case of beam anomalies. This paper outlines how main challenges of the imaging systems have been addressed, and the status of deployment as ESS gets closer to beam.

Place, publisher, year, edition, pages
ACoW Publishing, 2022
Keywords
ESS proton, beam, imaging systems
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
urn:nbn:se:hv:diva-20878 (URN)10.18429/JACoW-LINAC2022-TUPOJO20 (DOI)2-s2.0-85171299212 (Scopus ID)
Conference
31st International Linear Accelerator Conference LINAC2022, Liverpool, United Kingdom
Note

CC BY 4.0

Available from: 2023-12-28 Created: 2023-12-28 Last updated: 2024-02-15
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ORCID iD: ORCID iD iconorcid.org/0000-0003-1732-6544

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