Pub Date : 2024-05-17DOI: 10.1103/physrevaccelbeams.27.054801
Tobia Romano, Guntis Pikurs, Andris Ratkus, Toms Torims, Nicolas Delerue, Maurizio Vretenar, Lukas Stepien, Elena López, Maurizio Vedani
Metal additive manufacturing technologies are rapidly becoming an integral part of the advanced technological portfolio for the most demanding industrial applications. These processes are capable of fabricating three-dimensional components with near-net shape quality by depositing the constituent materials in a layer-by-layer fashion. This fabrication approach provides numerous advantages over conventional manufacturing methods, including enhanced design flexibility, reduced production costs and lead times, rapid prototyping, and the possibility to repair damaged parts. In recent years, the growing demand for novel accelerator components with improved performance characteristics, integrating structures such as drift tubes and internal cooling channels, has prompted the exploration of additive manufacturing in the field of particle accelerators. Radio-frequency components, beam intercepting devices, and vacuum systems have been prototyped using various metallic materials and additive manufacturing technologies, demonstrating performance levels comparable to the conventionally manufactured counterparts in preliminary tests. However, the absence of established qualification protocols and the uncertain reliability of additively manufactured parts under the demanding conditions typical of accelerator applications pose significant challenges to the integration of additive manufacturing processes into the fabrication practices of these components. This paper provides a comprehensive review of documented applications of metal additive manufacturing in particle accelerators, highlighting benefits, challenges, and opportunities for future improvements. The main requirements and currently available test setups for the assessment of additively manufactured components in applications involving ultrahigh vacuum and intense electromagnetic fields are also discussed.
{"title":"Metal additive manufacturing for particle accelerator applications","authors":"Tobia Romano, Guntis Pikurs, Andris Ratkus, Toms Torims, Nicolas Delerue, Maurizio Vretenar, Lukas Stepien, Elena López, Maurizio Vedani","doi":"10.1103/physrevaccelbeams.27.054801","DOIUrl":"https://doi.org/10.1103/physrevaccelbeams.27.054801","url":null,"abstract":"Metal additive manufacturing technologies are rapidly becoming an integral part of the advanced technological portfolio for the most demanding industrial applications. These processes are capable of fabricating three-dimensional components with near-net shape quality by depositing the constituent materials in a layer-by-layer fashion. This fabrication approach provides numerous advantages over conventional manufacturing methods, including enhanced design flexibility, reduced production costs and lead times, rapid prototyping, and the possibility to repair damaged parts. In recent years, the growing demand for novel accelerator components with improved performance characteristics, integrating structures such as drift tubes and internal cooling channels, has prompted the exploration of additive manufacturing in the field of particle accelerators. Radio-frequency components, beam intercepting devices, and vacuum systems have been prototyped using various metallic materials and additive manufacturing technologies, demonstrating performance levels comparable to the conventionally manufactured counterparts in preliminary tests. However, the absence of established qualification protocols and the uncertain reliability of additively manufactured parts under the demanding conditions typical of accelerator applications pose significant challenges to the integration of additive manufacturing processes into the fabrication practices of these components. This paper provides a comprehensive review of documented applications of metal additive manufacturing in particle accelerators, highlighting benefits, challenges, and opportunities for future improvements. The main requirements and currently available test setups for the assessment of additively manufactured components in applications involving ultrahigh vacuum and intense electromagnetic fields are also discussed.","PeriodicalId":54297,"journal":{"name":"Physical Review Accelerators and Beams","volume":"49 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141063360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-17DOI: 10.1103/physrevaccelbeams.27.051301
K. A. Ivanov, D. A. Gorlova, I. N. Tsymbalov, I. P. Tsygvintsev, S. A. Shulyapov, R. V. Volkov, A. B. Savel’ev
The simultaneous laser-driven acceleration and angular manipulation of the fast electron beam are experimentally demonstrated. The bunch of multi-MeV energy charged particles is generated during the propagation of the femtosecond laser pulse through the near-critical plasma slab accompanied by plasma channeling. Plasma is formed by the controlled breakdown of a thin-tape target by a powerful nanosecond prepulse. The electron beam pointing approach is based on the refraction of a laser pulse in the presence of a strong radial density gradient in the breakdown of the tape with a small displacement of the femtosecond laser beam relative to the breakdown symmetry axis. A shift of several micrometers makes it possible to achieve beam deflection by an angle up to 10° with acceptable beam charge and spectrum conservation. This opens up opportunities for in situ applications for scanning objects with an electron beam and the multistage electron beam energy gain in consecutive laser accelerators without bulk magnetic optics for particles. Experimental findings are supported by numerical particle-in-cell calculations of laser-plasma acceleration and hydrodynamic simulations.
{"title":"Laser-driven pointed acceleration of electrons with preformed plasma lens","authors":"K. A. Ivanov, D. A. Gorlova, I. N. Tsymbalov, I. P. Tsygvintsev, S. A. Shulyapov, R. V. Volkov, A. B. Savel’ev","doi":"10.1103/physrevaccelbeams.27.051301","DOIUrl":"https://doi.org/10.1103/physrevaccelbeams.27.051301","url":null,"abstract":"The simultaneous laser-driven acceleration and angular manipulation of the fast electron beam are experimentally demonstrated. The bunch of multi-MeV energy charged particles is generated during the propagation of the femtosecond laser pulse through the near-critical plasma slab accompanied by plasma channeling. Plasma is formed by the controlled breakdown of a thin-tape target by a powerful nanosecond prepulse. The electron beam pointing approach is based on the refraction of a laser pulse in the presence of a strong radial density gradient in the breakdown of the tape with a small displacement of the femtosecond laser beam relative to the breakdown symmetry axis. A shift of several micrometers makes it possible to achieve beam deflection by an angle up to 10° with acceptable beam charge and spectrum conservation. This opens up opportunities for <i>in situ</i> applications for scanning objects with an electron beam and the multistage electron beam energy gain in consecutive laser accelerators without bulk magnetic optics for particles. Experimental findings are supported by numerical particle-in-cell calculations of laser-plasma acceleration and hydrodynamic simulations.","PeriodicalId":54297,"journal":{"name":"Physical Review Accelerators and Beams","volume":"40 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141063281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Active plasma lensing, a compact method for intensifying the focus of charged particle beams by providing a magnetic field gradient of kT/m, has emerged as a sought-after technology in laser plasma accelerator applications. However, the utilization of active plasma lenses faces significant hurdles when dealing with laser-driven proton pulses, characterized by their broad bandwidth and high divergence. To address this challenge, we developed a novel active plasma lens with a variable radius, specifically designed to optimize lens geometry in accordance with the beam envelope, and performed the first measurement of its focusing ability. The experimental findings reveal that, compared to conventional cylindrical active plasma lenses, our radius-varying lens exhibits a 2.0-fold improvement in single-energy transmission efficiency, while maintaining comparable achromatic ability. This breakthrough is anticipated to significantly contribute to the miniaturization of laser proton accelerators.
{"title":"Experimental demonstration of radius-varying active plasma lensing for laser-plasma-accelerated proton beams with increased collection angle","authors":"Yang Yan, Tong Yang, Zhen Guo, Mingfeng Huang, Hao Cheng, Yuze Li, Yanlv Fang, Chentong Li, Yadong Xia, Qiangyou He, Yiting Yan, Chen Lin, Xueqing Yan","doi":"10.1103/physrevaccelbeams.27.052802","DOIUrl":"https://doi.org/10.1103/physrevaccelbeams.27.052802","url":null,"abstract":"Active plasma lensing, a compact method for intensifying the focus of charged particle beams by providing a magnetic field gradient of kT/m, has emerged as a sought-after technology in laser plasma accelerator applications. However, the utilization of active plasma lenses faces significant hurdles when dealing with laser-driven proton pulses, characterized by their broad bandwidth and high divergence. To address this challenge, we developed a novel active plasma lens with a variable radius, specifically designed to optimize lens geometry in accordance with the beam envelope, and performed the first measurement of its focusing ability. The experimental findings reveal that, compared to conventional cylindrical active plasma lenses, our radius-varying lens exhibits a 2.0-fold improvement in single-energy transmission efficiency, while maintaining comparable achromatic ability. This breakthrough is anticipated to significantly contribute to the miniaturization of laser proton accelerators.","PeriodicalId":54297,"journal":{"name":"Physical Review Accelerators and Beams","volume":"44 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140939524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-10DOI: 10.1103/physrevaccelbeams.27.053201
R. Ganter, P. Braschoss, H.-H. Braun, J. Buchmann, A. Citterio, M. Dehler, N. Gaiffi, N. Kirchgeorg, M. Magjar, C. Rosenberg, D. Stephan, L. Schulz, R. Sieber, X. Wang, A. Zandonella
The vacuum chambers for diffraction limited storage ring differ from the previous storage rings generation in three main aspects: the cross-section dimension, which is divided by a factor of 2 or more to fit smaller magnet apertures; the material, which includes much more copper for heat dissipation and to limit resistive wakefields; the coating of the inner surface with a nonevaporable getter (NEG) to ensure good pumping level despite low conductance. This paper gives a detailed description of the vacuum chambers’ design used in the arc section of SLS 2.0, starting with conceptual design choices based among others on synchrotron radiation heat and wakefield considerations. The particular case of the main bending magnet vacuum chamber is explained in detail from design to manufacturing, including the development of an appropriate NEG coating procedure. Finally, the overall assembly of a 17 m long arc, its activation to reach pressure in the range followed by transport and installation into the magnets is presented. This validates the choice of ex situ activation for an arc vessel made out of copper, with wall thicknesses as small as 1 mm and with less than 0.5 mm clearance to magnet poles.
{"title":"Vacuum chambers for Swiss Light Source arcs","authors":"R. Ganter, P. Braschoss, H.-H. Braun, J. Buchmann, A. Citterio, M. Dehler, N. Gaiffi, N. Kirchgeorg, M. Magjar, C. Rosenberg, D. Stephan, L. Schulz, R. Sieber, X. Wang, A. Zandonella","doi":"10.1103/physrevaccelbeams.27.053201","DOIUrl":"https://doi.org/10.1103/physrevaccelbeams.27.053201","url":null,"abstract":"The vacuum chambers for diffraction limited storage ring differ from the previous storage rings generation in three main aspects: the cross-section dimension, which is divided by a factor of 2 or more to fit smaller magnet apertures; the material, which includes much more copper for heat dissipation and to limit resistive wakefields; the coating of the inner surface with a nonevaporable getter (NEG) to ensure good pumping level despite low conductance. This paper gives a detailed description of the vacuum chambers’ design used in the arc section of SLS 2.0, starting with conceptual design choices based among others on synchrotron radiation heat and wakefield considerations. The particular case of the main bending magnet vacuum chamber is explained in detail from design to manufacturing, including the development of an appropriate NEG coating procedure. Finally, the overall assembly of a 17 m long arc, its activation to reach pressure in the <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow><mrow><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>11</mn></mrow></msup></mrow><mtext> </mtext><mtext> </mtext><mi>mbar</mi></mrow></math> range followed by transport and installation into the magnets is presented. This validates the choice of <i>ex situ</i> activation for an arc vessel made out of copper, with wall thicknesses as small as 1 mm and with less than 0.5 mm clearance to magnet poles.","PeriodicalId":54297,"journal":{"name":"Physical Review Accelerators and Beams","volume":"18 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140939567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-10DOI: 10.1103/physrevaccelbeams.27.052001
Ilan Ben-Zvi, Graeme Burt, Alejandro Castilla, Alick Macpherson, Nicholas Shipman
We present a novel design of a ferroelectric fast reactive tuner (FE-FRT) capable of modulating mega-VAR reactive power on a submicrosecond timescale. The high reactive power capability of our design extends the range of applications of reactive tuners to numerous applications. We present a detailed analytical model of the performance of a megawatt-class reactive power device and benchmark it against finite-element method eigenmode and frequency domain electromagnetic simulations. We introduce new features, including an annulus design for the ferroelectric capacitors and capacitive window coupling to the cavity. We consider thermal design issues and nonlinear effects in the ferroelectric. The model covers several configurations, allowing control of the frequency of superconducting and normal-conducting cavities in a variety of applications and frequencies. We calculate that the FE-FRT designed should be capable of handling around 0.45 MVAR of reactive power with around 3 kW of resistive losses, providing a frequency tuning range of 8 kHz in an example of 400 MHz cavity geometry.
{"title":"Conceptual design of a high reactive-power ferroelectric fast reactive tuner","authors":"Ilan Ben-Zvi, Graeme Burt, Alejandro Castilla, Alick Macpherson, Nicholas Shipman","doi":"10.1103/physrevaccelbeams.27.052001","DOIUrl":"https://doi.org/10.1103/physrevaccelbeams.27.052001","url":null,"abstract":"We present a novel design of a ferroelectric fast reactive tuner (FE-FRT) capable of modulating mega-VAR reactive power on a submicrosecond timescale. The high reactive power capability of our design extends the range of applications of reactive tuners to numerous applications. We present a detailed analytical model of the performance of a megawatt-class reactive power device and benchmark it against finite-element method eigenmode and frequency domain electromagnetic simulations. We introduce new features, including an annulus design for the ferroelectric capacitors and capacitive window coupling to the cavity. We consider thermal design issues and nonlinear effects in the ferroelectric. The model covers several configurations, allowing control of the frequency of superconducting and normal-conducting cavities in a variety of applications and frequencies. We calculate that the FE-FRT designed should be capable of handling around 0.45 MVAR of reactive power with around 3 kW of resistive losses, providing a frequency tuning range of 8 kHz in an example of 400 MHz cavity geometry.","PeriodicalId":54297,"journal":{"name":"Physical Review Accelerators and Beams","volume":"25 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140939466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-09DOI: 10.1103/physrevaccelbeams.27.054701
Alberto Degiovanniet al.
The Linac for Image Guided Hadron Therapy (LIGHT) system has been developed as the first commercial high-frequency linac-based proton therapy accelerator system. As part of the development process and of the technical validation of the concept, a reduced energy prototype linac (including all the key functional aspects of the full energy accelerator) has been designed and tested in parallel with the preparation work for a full-scale system. The LIGHT prototype construction, installation, and commissioning with beam allowed the identification of technical gaps and design improvements before the transfer to a medical device implementation. This paper gives a comprehensive summary of the design and integration aspects and presents for the first time the results achieved with the LIGHT prototype that was installed and commissioned on CERN premises in the years 2015–2019.
{"title":"Design, integration, and commissioning of the first linac for image guided hadron therapy prototype","authors":"Alberto Degiovanniet al.","doi":"10.1103/physrevaccelbeams.27.054701","DOIUrl":"https://doi.org/10.1103/physrevaccelbeams.27.054701","url":null,"abstract":"The Linac for Image Guided Hadron Therapy (LIGHT) system has been developed as the first commercial high-frequency linac-based proton therapy accelerator system. As part of the development process and of the technical validation of the concept, a reduced energy prototype linac (including all the key functional aspects of the full energy accelerator) has been designed and tested in parallel with the preparation work for a full-scale system. The LIGHT prototype construction, installation, and commissioning with beam allowed the identification of technical gaps and design improvements before the transfer to a medical device implementation. This paper gives a comprehensive summary of the design and integration aspects and presents for the first time the results achieved with the LIGHT prototype that was installed and commissioned on CERN premises in the years 2015–2019.","PeriodicalId":54297,"journal":{"name":"Physical Review Accelerators and Beams","volume":"304 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140939519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-08DOI: 10.1103/physrevaccelbeams.27.054001
S. Y. Lee, L. K. Nguyen
We study the feasibility of storing cold neutron beams in a strong focusing synchrotron. We also propose an alternating-current (ac) dipole magnet to be used as a neutron acceleration device and a pulsed quadrupole as a neutron beam kicker for injection and extraction. The ac acceleration device can provide adiabatic capture, acceleration, or deceleration of neutron beams. It seems feasible to design a high-quality neutron synchrotron for many future neutron beam applications, such as neutron life time measurements, monoenergetic neutron scattering experiments, and pencil neutron beam applications. This synchrotron can also be used as an injector for a neutron accumulator ring.
{"title":"Feasibility of a strong focusing synchrotron for cold neutron beams","authors":"S. Y. Lee, L. K. Nguyen","doi":"10.1103/physrevaccelbeams.27.054001","DOIUrl":"https://doi.org/10.1103/physrevaccelbeams.27.054001","url":null,"abstract":"We study the feasibility of storing cold neutron beams in a strong focusing synchrotron. We also propose an alternating-current (ac) dipole magnet to be used as a neutron acceleration device and a pulsed quadrupole as a neutron beam kicker for injection and extraction. The ac acceleration device can provide adiabatic capture, acceleration, or deceleration of neutron beams. It seems feasible to design a high-quality neutron synchrotron for many future neutron beam applications, such as neutron life time measurements, monoenergetic neutron scattering experiments, and pencil neutron beam applications. This synchrotron can also be used as an injector for a neutron accumulator ring.","PeriodicalId":54297,"journal":{"name":"Physical Review Accelerators and Beams","volume":"198 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140939376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-06DOI: 10.1103/physrevaccelbeams.27.051001
P. Baudrenghien, T. Mastoridis
The High-Luminosity LHC (HL-LHC) upgrade with planned operation from 2029 onward has a goal of achieving a tenfold increase in the integrated number of recorded collisions thanks to a doubling of the intensity per bunch ( protons) and a reduction of (the value in the two high luminosity detectors, namely ATLAS and CMS) to 15 cm. Such an increase in recorded collisions would significantly expedite new discoveries and exploration. Crab cavities are an important component of the HL-LHC upgrade and will contribute strongly to achieving an increase in the number of recorded collisions. However, noise injected through the crab cavity radio frequency (rf) system could cause significant transverse emittance growth and limit luminosity lifetime. We presented a theoretical formalism relating transverse emittance growth to rf noise in an earlier work. In this follow-up paper, we summarize measurements in the super-proton synchrotron (SPS) at CERN that validate the theory, we present estimates of the emittance growth rates using state-of-the-art rf and low-level rf (LLRF) technologies, and we set the rf noise specifications to achieve acceptable performance. A novel dedicated feedback system acting through the crab cavities to mitigate emittance growth will be required. In this work, we develop a theoretical formalism to evaluate the performance of such a feedback system in any collider, identify limiting components, present simulation results to validate these studies, and derive key design parameters for an HL-LHC implementation of such a feedback system.
{"title":"Transverse emittance growth due to rf noise in crab cavities: Theory, measurements, cure, and high luminosity LHC estimates","authors":"P. Baudrenghien, T. Mastoridis","doi":"10.1103/physrevaccelbeams.27.051001","DOIUrl":"https://doi.org/10.1103/physrevaccelbeams.27.051001","url":null,"abstract":"The High-Luminosity LHC (HL-LHC) upgrade with planned operation from 2029 onward has a goal of achieving a tenfold increase in the integrated number of recorded collisions thanks to a doubling of the intensity per bunch (<math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mn>2.2</mn><mo>×</mo><msup><mn>10</mn><mn>11</mn></msup></math> protons) and a reduction of <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><msup><mi>β</mi><mo>*</mo></msup></math> (the <math display=\"inline\" xmlns=\"http://www.w3.org/1998/Math/MathML\"><mi>β</mi></math> value in the two high luminosity detectors, namely ATLAS and CMS) to 15 cm. Such an increase in recorded collisions would significantly expedite new discoveries and exploration. Crab cavities are an important component of the HL-LHC upgrade and will contribute strongly to achieving an increase in the number of recorded collisions. However, noise injected through the crab cavity radio frequency (rf) system could cause significant transverse emittance growth and limit luminosity lifetime. We presented a theoretical formalism relating transverse emittance growth to rf noise in an earlier work. In this follow-up paper, we summarize measurements in the super-proton synchrotron (SPS) at CERN that validate the theory, we present estimates of the emittance growth rates using state-of-the-art rf and low-level rf (LLRF) technologies, and we set the rf noise specifications to achieve acceptable performance. A novel dedicated feedback system acting through the crab cavities to mitigate emittance growth will be required. In this work, we develop a theoretical formalism to evaluate the performance of such a feedback system in any collider, identify limiting components, present simulation results to validate these studies, and derive key design parameters for an HL-LHC implementation of such a feedback system.","PeriodicalId":54297,"journal":{"name":"Physical Review Accelerators and Beams","volume":"28 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-05-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140882880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new high transmission efficiency, easily tunable, and cost-effective beam collection system is proposed for laser-accelerated proton beams with large divergence angles and wide energy spectra. In previous experiments conducted at the compact laser plasma accelerator platform of Peking University, a beamline was initially constructed with a collection system based on an electromagnetic quadrupoles (EMQs) triplet. However, due to the limited acceptance angle, the EMQs exhibited a monoenergetic transmission efficiency of only 10% to 20% for laser accelerated proton beams. Permanent magnet quadrupoles (PMQs), known for their high magnetic field gradients, compact size, and lower expenses, are well suited for integration with other readily adjustable transmission elements like EMQs and solenoids, effectively enhancing the beam collection capabilities of the system. In this paper, we show that by introducing a pair of centimeter-sized PMQs in front of the EMQs for beam prefocusing, the beam’s transverse size is quickly compressed, enabling transmission of highly divergent protons. Experimental results demonstrate that the prefocusing by PMQs increased the system’s transmission efficiency by a factor of 2.44 to 6.01 compared to the original setup, while also enhancing the energy selection based on stronger chromatic effect. This method can be extended to 100 MeV high-energy proton beamlines and is crucial for applications of laser plasma accelerators.
{"title":"High transmission efficiency collection system for laser-accelerated proton beams based on permanent magnet quadrupoles prefocusing","authors":"Yang Yan, Hao Cheng, Yuze Li, Yanlv Fang, Yadong Xia, Qiangyou He, Chentong Li, Fangnan Li, Zhen Guo, Yiting Yan, Mingfeng Huang, Minjian Wu, Kedong Wang, Kun Zhu, Xueqing Yan, Chen Lin","doi":"10.1103/physrevaccelbeams.27.052801","DOIUrl":"https://doi.org/10.1103/physrevaccelbeams.27.052801","url":null,"abstract":"A new high transmission efficiency, easily tunable, and cost-effective beam collection system is proposed for laser-accelerated proton beams with large divergence angles and wide energy spectra. In previous experiments conducted at the compact laser plasma accelerator platform of Peking University, a beamline was initially constructed with a collection system based on an electromagnetic quadrupoles (EMQs) triplet. However, due to the limited acceptance angle, the EMQs exhibited a monoenergetic transmission efficiency of only 10% to 20% for laser accelerated proton beams. Permanent magnet quadrupoles (PMQs), known for their high magnetic field gradients, compact size, and lower expenses, are well suited for integration with other readily adjustable transmission elements like EMQs and solenoids, effectively enhancing the beam collection capabilities of the system. In this paper, we show that by introducing a pair of centimeter-sized PMQs in front of the EMQs for beam prefocusing, the beam’s transverse size is quickly compressed, enabling transmission of highly divergent protons. Experimental results demonstrate that the prefocusing by PMQs increased the system’s transmission efficiency by a factor of 2.44 to 6.01 compared to the original setup, while also enhancing the energy selection based on stronger chromatic effect. This method can be extended to 100 MeV high-energy proton beamlines and is crucial for applications of laser plasma accelerators.","PeriodicalId":54297,"journal":{"name":"Physical Review Accelerators and Beams","volume":"25 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140826960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-26DOI: 10.1103/physrevaccelbeams.27.040702
Shaukat Khan, Giovanni Perosa, Filippo Sottocorona, Alexander Brynes, Giovanni De Ninno, Giuseppe Penco, Primož Rebernic Ribič, Simone Spampinati, Carlo Spezzani, Mauro Trovò, Luca Giannessi, Enrico Allaria, Evgeny Schneidmiller, Eugenio Ferrari
Initiating the amplification process in a short-wavelength free-electron laser (FEL) by external seed laser pulses results in radiation with a high degree of longitudinal and transverse coherence. The basic layout in seeded harmonic generation involves a periodic electron energy modulation by laser-electron interaction in a short undulator (the “modulator”), which is converted into a density modulation in a dispersive section immediately followed by a long FEL undulator (the “radiator”) tuned to a harmonic of the seed laser wavelength. With the advent of more complex seeding schemes, density-modulated beams may need to be transported in drift sections before entering the radiator. Long FEL undulators may also contain several drift spaces to accommodate focusing elements and diagnostics. Therefore, it is of general interest to study the evolution of density-modulated electron beams in drift sections under the influence of repulsive Coulomb forces. At FERMI, a seeded FEL user facility in Trieste, Italy, systematic studies of the impact of varying drift length on coherent harmonic emission were undertaken. In order to make the underlying physics transparent, the emphasis of this paper is on reproducing the experimental findings with analytical estimates and a simple one-dimensional numerical model. Furthermore, the Coulomb forces in a drift section may be employed to enhance the laser-induced energy modulation and yield an improved density modulation before entering the FEL radiator.
通过外部种子激光脉冲启动短波长自由电子激光器（FEL）的放大过程，可产生具有高度纵向和横向相干性的辐射。种子谐波发生的基本布局包括在一个短的衰减器（"调制器"）中通过激光与电子的相互作用对电子能量进行周期性调制，然后在紧随其后的一个长的 FEL 衰减器（"辐射器"）中将其转换为密度调制。随着更复杂的种子计划的出现，密度调制光束在进入辐射器之前可能需要在漂移段中传输。长的 FEL 下行器还可能包含多个漂移空间，以容纳聚焦元件和诊断设备。因此，研究漂移段中密度调制电子束在库仑斥力影响下的演变具有普遍意义。在意大利的里雅斯特的FERMI--一个种子FEL用户设施--中，对漂移长度变化对相干谐波发射的影响进行了系统研究。为了使基本物理原理更加透明，本文的重点是通过分析估算和简单的一维数值模型再现实验结果。此外，漂移段中的库仑力可以用来增强激光诱导的能量调制，并在进入 FEL 辐射器之前产生更好的密度调制。
{"title":"Evolution of density-modulated electron beams in drift sections","authors":"Shaukat Khan, Giovanni Perosa, Filippo Sottocorona, Alexander Brynes, Giovanni De Ninno, Giuseppe Penco, Primož Rebernic Ribič, Simone Spampinati, Carlo Spezzani, Mauro Trovò, Luca Giannessi, Enrico Allaria, Evgeny Schneidmiller, Eugenio Ferrari","doi":"10.1103/physrevaccelbeams.27.040702","DOIUrl":"https://doi.org/10.1103/physrevaccelbeams.27.040702","url":null,"abstract":"Initiating the amplification process in a short-wavelength free-electron laser (FEL) by external seed laser pulses results in radiation with a high degree of longitudinal and transverse coherence. The basic layout in seeded harmonic generation involves a periodic electron energy modulation by laser-electron interaction in a short undulator (the “modulator”), which is converted into a density modulation in a dispersive section immediately followed by a long FEL undulator (the “radiator”) tuned to a harmonic of the seed laser wavelength. With the advent of more complex seeding schemes, density-modulated beams may need to be transported in drift sections before entering the radiator. Long FEL undulators may also contain several drift spaces to accommodate focusing elements and diagnostics. Therefore, it is of general interest to study the evolution of density-modulated electron beams in drift sections under the influence of repulsive Coulomb forces. At FERMI, a seeded FEL user facility in Trieste, Italy, systematic studies of the impact of varying drift length on coherent harmonic emission were undertaken. In order to make the underlying physics transparent, the emphasis of this paper is on reproducing the experimental findings with analytical estimates and a simple one-dimensional numerical model. Furthermore, the Coulomb forces in a drift section may be employed to enhance the laser-induced energy modulation and yield an improved density modulation before entering the FEL radiator.","PeriodicalId":54297,"journal":{"name":"Physical Review Accelerators and Beams","volume":"25 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140805703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：