Pub Date : 2018-08-01DOI: 10.1109/AAC.2018.8659424
Dongsung Kim, H. Andrews, R. Fleming, J. Lewellen, K. Nichols, V. Pavlenko, D. Shchegolkov, E. Simakov
We present the results of beam divergence studies for the diamond field emitter array (DFEA) cathodes producing high-current-density electron beams. At Los Alamos National Laboratory (LANL), we fabricate and test the micrometer-scale diamond pyramids with nanometer-scale sharp tips for use as an electron beam source for a compact dielectric laser accelerator. For the beam divergence measurements, we assembled a test stand consisting of a DFEA cathode, a small mesh aperture anode, and a screen representing of a sapphire disk coated with ZnO (AZO) for beam visualization. A negative voltage of about 40 keV is applied to the cathode, and the mesh and the screen are kept at ground. We record the spot size corresponding to the size of the electron beam on the AZO screen past the mesh anode at different mesh to screen distances. We also conduct the beam dynamics simulations with General particle Tracer (GPT). In this paper, we present the results of the experimental measurements and GPT simulations, along with calculations of the beam's divergence.
本文介绍了金刚石场发射极阵列阴极产生高电流密度电子束的发散研究结果。在洛斯阿拉莫斯国家实验室(Los Alamos National Laboratory, LANL)，我们制造并测试了微米级的钻石金字塔，其尖端为纳米级，可作为紧凑型介电激光加速器的电子束源。为了测量光束发散，我们组装了一个试验台，该试验台由DFEA阴极、一个小网格孔阳极和一个代表涂有ZnO (AZO)的蓝宝石盘的屏幕组成，用于光束可视化。阴极上施加约40 keV的负电压，栅极和屏幕保持在地面上。我们记录了与电子束尺寸相对应的光斑尺寸，这些光斑尺寸在不同的栅极到栅极的距离上通过AZO屏幕。我们还用通用粒子追踪器(GPT)进行了光束动力学模拟。在本文中，我们给出了实验测量和GPT模拟的结果，以及光束散度的计算。
{"title":"Study of the Beam Divergence in Diamond Field Emitter Array Cathodes","authors":"Dongsung Kim, H. Andrews, R. Fleming, J. Lewellen, K. Nichols, V. Pavlenko, D. Shchegolkov, E. Simakov","doi":"10.1109/AAC.2018.8659424","DOIUrl":"https://doi.org/10.1109/AAC.2018.8659424","url":null,"abstract":"We present the results of beam divergence studies for the diamond field emitter array (DFEA) cathodes producing high-current-density electron beams. At Los Alamos National Laboratory (LANL), we fabricate and test the micrometer-scale diamond pyramids with nanometer-scale sharp tips for use as an electron beam source for a compact dielectric laser accelerator. For the beam divergence measurements, we assembled a test stand consisting of a DFEA cathode, a small mesh aperture anode, and a screen representing of a sapphire disk coated with ZnO (AZO) for beam visualization. A negative voltage of about 40 keV is applied to the cathode, and the mesh and the screen are kept at ground. We record the spot size corresponding to the size of the electron beam on the AZO screen past the mesh anode at different mesh to screen distances. We also conduct the beam dynamics simulations with General particle Tracer (GPT). In this paper, we present the results of the experimental measurements and GPT simulations, along with calculations of the beam's divergence.","PeriodicalId":339772,"journal":{"name":"2018 IEEE Advanced Accelerator Concepts Workshop (AAC)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121925447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-01DOI: 10.1109/AAC.2018.8659392
J. Vay, A. Almgren, J. Bell, R. Lehe, A. Myers, Jaehong Park, Olga Shapoval, M. Thévenet, Weiqun Zhang, D. Grote, M. Hogan, L. Ge, C. Ng
Turning the current experimental plasma accelerator state-of-the-art from a promising technology into mainstream scientific tools depends critically on high-performance, high-fidelity modeling of complex processes that develop over a wide range of space and time scales. As part of the U.S. Department of Energy's Exascale Computing Project, a team composed of Lawrence Berkeley National Laboratory, SLAC Accelerator National Laboratory and Lawrence Livermore National Laboratory researchers is developing a new open-source plasma accelerator simulation tool. The new software will harness the power of future exascale supercomputers for the exploration of outstanding questions in the physics of acceleration and transport of particle beams in chains of plasma channels. This will benefit the ultimate goal of compact and affordable high-energy physics colliders, and many spinoff applications of plasma accelerators along the way. We give an update on some of the code latest developments and discuss future plans.
{"title":"Toward Plasma Wakefield Simulations at Exascale","authors":"J. Vay, A. Almgren, J. Bell, R. Lehe, A. Myers, Jaehong Park, Olga Shapoval, M. Thévenet, Weiqun Zhang, D. Grote, M. Hogan, L. Ge, C. Ng","doi":"10.1109/AAC.2018.8659392","DOIUrl":"https://doi.org/10.1109/AAC.2018.8659392","url":null,"abstract":"Turning the current experimental plasma accelerator state-of-the-art from a promising technology into mainstream scientific tools depends critically on high-performance, high-fidelity modeling of complex processes that develop over a wide range of space and time scales. As part of the U.S. Department of Energy's Exascale Computing Project, a team composed of Lawrence Berkeley National Laboratory, SLAC Accelerator National Laboratory and Lawrence Livermore National Laboratory researchers is developing a new open-source plasma accelerator simulation tool. The new software will harness the power of future exascale supercomputers for the exploration of outstanding questions in the physics of acceleration and transport of particle beams in chains of plasma channels. This will benefit the ultimate goal of compact and affordable high-energy physics colliders, and many spinoff applications of plasma accelerators along the way. We give an update on some of the code latest developments and discuss future plans.","PeriodicalId":339772,"journal":{"name":"2018 IEEE Advanced Accelerator Concepts Workshop (AAC)","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126245213","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-01DOI: 10.18429/JACOW-IPAC2018-THPAL024
R. Fleming, H. Andrews, K. Bishofberger, Dongsung Kim, J. Lewellen, K. Nichols, D. Shchegolkov, E. Simakov
We present the design and initial test results for a simple, variable-focus solenoidal lens with integrated emittance filtering. The design was developed as a first-iteration injection optics solution for transport of a beam from a field-emitter cathode into a dielectric laser accelerator structure. The design is easy to fabricate and, while based on permanent magnets, can be readily modified to allow for remote control of the focal length. The emittance is controlled via a selection of collimating irises. The focal length can be changed by altering the spacing between the two permanent ring magnets. This allowed us to focus a 1.6 μA beam to a 10 μm spot size.
{"title":"A Simple Variable Focus Lens for Field-Emitter Cathodes","authors":"R. Fleming, H. Andrews, K. Bishofberger, Dongsung Kim, J. Lewellen, K. Nichols, D. Shchegolkov, E. Simakov","doi":"10.18429/JACOW-IPAC2018-THPAL024","DOIUrl":"https://doi.org/10.18429/JACOW-IPAC2018-THPAL024","url":null,"abstract":"We present the design and initial test results for a simple, variable-focus solenoidal lens with integrated emittance filtering. The design was developed as a first-iteration injection optics solution for transport of a beam from a field-emitter cathode into a dielectric laser accelerator structure. The design is easy to fabricate and, while based on permanent magnets, can be readily modified to allow for remote control of the focal length. The emittance is controlled via a selection of collimating irises. The focal length can be changed by altering the spacing between the two permanent ring magnets. This allowed us to focus a 1.6 μA beam to a 10 μm spot size.","PeriodicalId":339772,"journal":{"name":"2018 IEEE Advanced Accelerator Concepts Workshop (AAC)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114175438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-01DOI: 10.1109/AAC.2018.8659432
R. Lehe, W. An
Working group 2 (Computations for Accelerator Physics) reviewed recent progress in numerical simulations for advanced accelerators. This included discussions of algorithmic and code developments, as well as applications to particular types of accelerators.
{"title":"Summary of Working Group 2: Computations for Accelerator Physics","authors":"R. Lehe, W. An","doi":"10.1109/AAC.2018.8659432","DOIUrl":"https://doi.org/10.1109/AAC.2018.8659432","url":null,"abstract":"Working group 2 (Computations for Accelerator Physics) reviewed recent progress in numerical simulations for advanced accelerators. This included discussions of algorithmic and code developments, as well as applications to particular types of accelerators.","PeriodicalId":339772,"journal":{"name":"2018 IEEE Advanced Accelerator Concepts Workshop (AAC)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128191424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-01DOI: 10.1109/AAC.2018.8659426
T. Egenolf, U. Niedermayer, O. Boine-Frankenheim
In Dielectric Laser Accelerators (DLAs) apertures are in submicrometer range. Intensity effects caused by wake-fields are the critical limitations at relativistic energies. To estimate the intensity limits, we present simulations of longitudinal and transverse wakefields for different DLA grating geometries. These simulations enable to calculate the longitudinal beam loading limit. Additionally, coherent transverse beam stabilities are analyzed. Based on these studies, we estimate the influence of wakes on DLA experiments at 3 GeV planned at SwissFEL at the Paul Scherrer Institute (PSI). However, most models of transverse instabilities are valid only for linearized wakes, which holds at most in a fraction of the aperture. To take this into account, we outline the integration of a nonlinear wake kick in our simplified 6D particle tracking code DLAtrack6D. For verification, we compare both the linear and nonlinear tracking results to full Particle-In-Cell simulations.
{"title":"Intensity Limits by Wakefields in Relativistic Dielectric Laser Acceleration Grating Structures","authors":"T. Egenolf, U. Niedermayer, O. Boine-Frankenheim","doi":"10.1109/AAC.2018.8659426","DOIUrl":"https://doi.org/10.1109/AAC.2018.8659426","url":null,"abstract":"In Dielectric Laser Accelerators (DLAs) apertures are in submicrometer range. Intensity effects caused by wake-fields are the critical limitations at relativistic energies. To estimate the intensity limits, we present simulations of longitudinal and transverse wakefields for different DLA grating geometries. These simulations enable to calculate the longitudinal beam loading limit. Additionally, coherent transverse beam stabilities are analyzed. Based on these studies, we estimate the influence of wakes on DLA experiments at 3 GeV planned at SwissFEL at the Paul Scherrer Institute (PSI). However, most models of transverse instabilities are valid only for linearized wakes, which holds at most in a fraction of the aperture. To take this into account, we outline the integration of a nonlinear wake kick in our simplified 6D particle tracking code DLAtrack6D. For verification, we compare both the linear and nonlinear tracking results to full Particle-In-Cell simulations.","PeriodicalId":339772,"journal":{"name":"2018 IEEE Advanced Accelerator Concepts Workshop (AAC)","volume":"171 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123363444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-01DOI: 10.1109/AAC.2018.8659422
M. Litos, R. Ariniello, C. Doss, K. Hunt-Stone, J. Cary
The ion channel laser (ICL) was originally proposed as a compact, plasma-based alternative to the free electron laser (FEL) [1]. It is, in many ways, analogous to the FEL, though it offers some distinct advantages all on its own. Most notably, the ICL can accommodate a larger electron energy spread, making it better suited for high-brightness plasma-injected beams. In addition, the same radiator (plasma source) can be used to produce elliptically polarized light without alteration, a feature that is absent in an FEL. Historically, electron beam quality and plasma source development were insufficient for the demonstration of the ICL. In addition, the ICL appeared unfavorable due to the inherently short Rayleigh length of the radiation it produced. Recent literature, however, has shown that high gain can be achieved, despite the short Rayleigh length [2]. In addition, current and near-future facilities are able to provide appropriate beams and plasma sources for the ICL. Experimental opportunities to demonstrate an ICL at the Facility for Advanced Accelerator Experimental Tests II (FACET-II) are presented, utilizing both a 10 GeV beam originating from the SLAC National Accelerator Laboratory linac, and a 1 GeV high-brightness, plasma-injected beam.
{"title":"Experimental Opportunities for the Ion Channel Laser","authors":"M. Litos, R. Ariniello, C. Doss, K. Hunt-Stone, J. Cary","doi":"10.1109/AAC.2018.8659422","DOIUrl":"https://doi.org/10.1109/AAC.2018.8659422","url":null,"abstract":"The ion channel laser (ICL) was originally proposed as a compact, plasma-based alternative to the free electron laser (FEL) [1]. It is, in many ways, analogous to the FEL, though it offers some distinct advantages all on its own. Most notably, the ICL can accommodate a larger electron energy spread, making it better suited for high-brightness plasma-injected beams. In addition, the same radiator (plasma source) can be used to produce elliptically polarized light without alteration, a feature that is absent in an FEL. Historically, electron beam quality and plasma source development were insufficient for the demonstration of the ICL. In addition, the ICL appeared unfavorable due to the inherently short Rayleigh length of the radiation it produced. Recent literature, however, has shown that high gain can be achieved, despite the short Rayleigh length [2]. In addition, current and near-future facilities are able to provide appropriate beams and plasma sources for the ICL. Experimental opportunities to demonstrate an ICL at the Facility for Advanced Accelerator Experimental Tests II (FACET-II) are presented, utilizing both a 10 GeV beam originating from the SLAC National Accelerator Laboratory linac, and a 1 GeV high-brightness, plasma-injected beam.","PeriodicalId":339772,"journal":{"name":"2018 IEEE Advanced Accelerator Concepts Workshop (AAC)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129142782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-01DOI: 10.1109/AAC.2018.8659405
Yong Jiang, S. Shchelkunov, J. Hirshfield
There are tremendous challenges to provide a high intensity positron source capable of continuous beam delivery. It is particularly important to devise a high power (10-to-100 kW) production target with adequate heat dissipation, positron capture, and accelerator integration. Here a novel approach using a stationary target with beam dynamics manipulation is described. It is based on a few pairs of deflecting magnets to scan a high-power electron beam along a long track on the target, either in a linear raster or around a circle, and then combine the produced positrons back into an on-axis beam. Proper optics design of incident electron beam can significantly dilute the heat load and distribute evenly, thus avoid destructive focusing on a single spot, while achieving the ample production and collection of a positron beam. The fixed target assembly can allow a sufficient flow of the cooling water on the target perimeter to carry away the deposited heat without an undue temperature rise.
{"title":"Positron Production Target with Raster Beam","authors":"Yong Jiang, S. Shchelkunov, J. Hirshfield","doi":"10.1109/AAC.2018.8659405","DOIUrl":"https://doi.org/10.1109/AAC.2018.8659405","url":null,"abstract":"There are tremendous challenges to provide a high intensity positron source capable of continuous beam delivery. It is particularly important to devise a high power (10-to-100 kW) production target with adequate heat dissipation, positron capture, and accelerator integration. Here a novel approach using a stationary target with beam dynamics manipulation is described. It is based on a few pairs of deflecting magnets to scan a high-power electron beam along a long track on the target, either in a linear raster or around a circle, and then combine the produced positrons back into an on-axis beam. Proper optics design of incident electron beam can significantly dilute the heat load and distribute evenly, thus avoid destructive focusing on a single spot, while achieving the ample production and collection of a positron beam. The fixed target assembly can allow a sufficient flow of the cooling water on the target perimeter to carry away the deposited heat without an undue temperature rise.","PeriodicalId":339772,"journal":{"name":"2018 IEEE Advanced Accelerator Concepts Workshop (AAC)","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128679666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-01DOI: 10.1109/AAC.2018.8659386
Yong Jiang, X. Chang, S. Shchelkunov, Lin Wang, J. Hirshfield
An experimental research is being conducted at the Yale University Beam Physics Laboratory, aiming to confirm fundamental aspects of an as-yet untested two-beam collinear electron accelerator concept employing a detuned bimodal cavity structure. The features of this novel beam-driven accelerator concept include (i) interleaving of bunches of the low-current accelerated beam with bunches of the high-current drive beam, while both beams move along the same central axis in the structure; (ii) excitation by the drive beam of two modes of each cavity in the structure, with the frequency of the higher mode equal to three times the frequency of the fundamental TM010mode; and (iii) detuning of the cavity modes away from the frequency of the accelerated and drive beam bunches, and their third harmonic. Advantages that are anticipated from this approach include (a) operation at higher acceleration gradient with lower breakdown and pulsed heating rates than for a structure of single-mode cavities at the same acceleration gradient, due to the unconventional spatiotemporal field distributions in the bimodal cavities; (b) realization of a transformer ratio well above two, due to the detuning of the cavity modes; and (c) greater system simplicity and lower cost than for a two-beam accelerator with separate drive and accelerated beam-lines. The recent R&D progress is presented.
{"title":"Detuned-Structure-Based Beam-Driven Accelerator","authors":"Yong Jiang, X. Chang, S. Shchelkunov, Lin Wang, J. Hirshfield","doi":"10.1109/AAC.2018.8659386","DOIUrl":"https://doi.org/10.1109/AAC.2018.8659386","url":null,"abstract":"An experimental research is being conducted at the Yale University Beam Physics Laboratory, aiming to confirm fundamental aspects of an as-yet untested two-beam collinear electron accelerator concept employing a detuned bimodal cavity structure. The features of this novel beam-driven accelerator concept include (i) interleaving of bunches of the low-current accelerated beam with bunches of the high-current drive beam, while both beams move along the same central axis in the structure; (ii) excitation by the drive beam of two modes of each cavity in the structure, with the frequency of the higher mode equal to three times the frequency of the fundamental TM010mode; and (iii) detuning of the cavity modes away from the frequency of the accelerated and drive beam bunches, and their third harmonic. Advantages that are anticipated from this approach include (a) operation at higher acceleration gradient with lower breakdown and pulsed heating rates than for a structure of single-mode cavities at the same acceleration gradient, due to the unconventional spatiotemporal field distributions in the bimodal cavities; (b) realization of a transformer ratio well above two, due to the detuning of the cavity modes; and (c) greater system simplicity and lower cost than for a two-beam accelerator with separate drive and accelerated beam-lines. The recent R&D progress is presented.","PeriodicalId":339772,"journal":{"name":"2018 IEEE Advanced Accelerator Concepts Workshop (AAC)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124612757","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-01DOI: 10.1109/AAC.2018.8659413
O. Mohsen, Anusorn Lueansaramwong, S. Valluri, V. Korampally, P. Piot, S. Chattopadhyay
High-current electron beams have a wide range of applications. Generating such beams in a compact and robust way is appealing for some of these applications. Among the various high-current emission processes, field emission appears to be promising. One of its appealing featuring being its simplicity. In this paper, we report on preliminary experimental results on field-emission cathode consisting of self-assembled silicon nanocones. We discuss the setup employed for the measurements and present the current-voltage (I-V) characteristic curves along with the inferred field-enhancement factors.
{"title":"Field Emission from Silicon Nanocones Cathodes","authors":"O. Mohsen, Anusorn Lueansaramwong, S. Valluri, V. Korampally, P. Piot, S. Chattopadhyay","doi":"10.1109/AAC.2018.8659413","DOIUrl":"https://doi.org/10.1109/AAC.2018.8659413","url":null,"abstract":"High-current electron beams have a wide range of applications. Generating such beams in a compact and robust way is appealing for some of these applications. Among the various high-current emission processes, field emission appears to be promising. One of its appealing featuring being its simplicity. In this paper, we report on preliminary experimental results on field-emission cathode consisting of self-assembled silicon nanocones. We discuss the setup employed for the measurements and present the current-voltage (I-V) characteristic curves along with the inferred field-enhancement factors.","PeriodicalId":339772,"journal":{"name":"2018 IEEE Advanced Accelerator Concepts Workshop (AAC)","volume":"124 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122904333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-08-01DOI: 10.1109/AAC.2018.8659428
L. Fan-Chiang, H. Mao, W. Leemans
The ability to precisely shape gas jets for controlled injection of electrons in laser plasma accelerators (LPAs) is crucial for developing high quality electron beams. Verifying tailored density profiles has called for more detailed gas density diagnostics than those traditionally used. Most diagnostics give line-of-sight measurements, integrating over and blurring sharp asymmetric features. In this study, planar laser-induced fluorescence (PLIF) has been prototyped for characterizing laser plasma accelerator gas jet targets. PLIF has the distinct advantage of isolating a two-dimensional slice of the jet plume using a laser sheet. As a demonstration, gas jets whose flows were intercepted by a razor blade were characterized with PLIF. Fluorescent slices of the gas jet resulted in high resolution images which revealed changes in characteristic flow parameters with change in blade position. It was shown that PLIF is able to resolve thin features such as gas density shocks and other features on scales relevant for tailored LPA gas jet targets.
{"title":"Planar Laser-Induced Fluorescence Developed for Laser Plasma Accelerator Targets","authors":"L. Fan-Chiang, H. Mao, W. Leemans","doi":"10.1109/AAC.2018.8659428","DOIUrl":"https://doi.org/10.1109/AAC.2018.8659428","url":null,"abstract":"The ability to precisely shape gas jets for controlled injection of electrons in laser plasma accelerators (LPAs) is crucial for developing high quality electron beams. Verifying tailored density profiles has called for more detailed gas density diagnostics than those traditionally used. Most diagnostics give line-of-sight measurements, integrating over and blurring sharp asymmetric features. In this study, planar laser-induced fluorescence (PLIF) has been prototyped for characterizing laser plasma accelerator gas jet targets. PLIF has the distinct advantage of isolating a two-dimensional slice of the jet plume using a laser sheet. As a demonstration, gas jets whose flows were intercepted by a razor blade were characterized with PLIF. Fluorescent slices of the gas jet resulted in high resolution images which revealed changes in characteristic flow parameters with change in blade position. It was shown that PLIF is able to resolve thin features such as gas density shocks and other features on scales relevant for tailored LPA gas jet targets.","PeriodicalId":339772,"journal":{"name":"2018 IEEE Advanced Accelerator Concepts Workshop (AAC)","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122284459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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