The upcoming long baseline neutrino experiments aim to enhance proton beam power to multi-MW scale and utilize large-scale detectors to address the challenge of limited event statistics. The DUNE experiment at LBNF will test the three neutrino flavor paradigm and directly search for CP violation by studying oscillation signatures in the high intensity $nu_{mu}$ (anti-$nu_{mu}$) beam to $nu_{e}$ (anti-$nu_{e}$) measured over a long baseline. Higher beam power and improved accelerator up-time will enhance neutrino flux for the neutrino program by increasing the number of protons on target. LBNF/DUNE, as well as PIP-II upgrade and Accelerator Complex Evolution (ACE) plan, play a vital role in this effort. The scientific potential of ACE plan extends beyond neutrino physics, encompassing endeavors such as the Muon Collider, Charged Lepton Flavor Violation (CLFV), Dark Sectors, and exploration of neutrinos beyond DUNE.par In the era of higher-power accelerator operation , research in target materials and beam instrumentation is crucial for optimizing design modifications. This abstract discusses Fermilab ACE, the science opportunities it provides, and how Fermilab is pushing the limits of proton beam power and accelerator infrastructure. By tackling neutrino beam challenges and exploring research and development ideas, we are advancing our understanding of fundamental particles and their interactions.
{"title":"Neutrino Program at Fermilab -- Enhancing proton beam power and accelerator infrastructure","authors":"Ganguly SudeshnaFermilab","doi":"arxiv-2407.08038","DOIUrl":"https://doi.org/arxiv-2407.08038","url":null,"abstract":"The upcoming long baseline neutrino experiments aim to enhance proton beam\u0000power to multi-MW scale and utilize large-scale detectors to address the\u0000challenge of limited event statistics. The DUNE experiment at LBNF will test\u0000the three neutrino flavor paradigm and directly search for CP violation by\u0000studying oscillation signatures in the high intensity $nu_{mu}$\u0000(anti-$nu_{mu}$) beam to $nu_{e}$ (anti-$nu_{e}$) measured over a long\u0000baseline. Higher beam power and improved accelerator up-time will enhance\u0000neutrino flux for the neutrino program by increasing the number of protons on\u0000target. LBNF/DUNE, as well as PIP-II upgrade and Accelerator Complex Evolution\u0000(ACE) plan, play a vital role in this effort. The scientific potential of ACE\u0000plan extends beyond neutrino physics, encompassing endeavors such as the Muon\u0000Collider, Charged Lepton Flavor Violation (CLFV), Dark Sectors, and exploration\u0000of neutrinos beyond DUNE.par In the era of higher-power accelerator operation\u0000, research in target materials and beam instrumentation is crucial for\u0000optimizing design modifications. This abstract discusses Fermilab ACE, the\u0000science opportunities it provides, and how Fermilab is pushing the limits of\u0000proton beam power and accelerator infrastructure. By tackling neutrino beam\u0000challenges and exploring research and development ideas, we are advancing our\u0000understanding of fundamental particles and their interactions.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141613982","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}
Sebastian Maier, Miriam Brosi, Akira Mochihashi, Michael J. Nasse, Markus Schwarz, Anke-Susanne Müller
In the case of single-digit picosecond bunch length, synchrotron light sources produce intense coherent radiation up to the THz range. The reduction of the bunch length by lowering the momentum compaction factor (low-$alpha$) gives rise to the micro-bunching instability, which is on one hand a crucial roadblock in the X-ray range during to the resulting effective bunch lengthening but on the other hand also an opportunity for the generation of intense THz radiation if it can be controlled appropriately. In the KIT storage ring KARA (Karlsruhe Research Accelerator), two parallel plates with periodic rectangular corrugations are planned to be installed in an electron storage ring. These plates create an additional longitudinal impedance based on their geometry, which can affect the beam dynamics. The resulting impedance manipulation will be used to study and control the longitudinal electron beam dynamics and the emitted coherent synchrotron radiation (CSR). This paper presents the results of systematic studies in simulation of the impact of additional corrugated plate impedances on the longitudinal beam dynamics using the example of the KARA storage ring. If the periodicity of the wake function of the corrugated plates matches the size of the substructures in the longitudinal bunch profile, the instability threshold can be effectively manipulated. This extends intense THz radiation to different beam current regimes.
在束长为个位数皮秒的情况下，同步辐射光源会产生高达太赫兹范围的强相干辐射。通过降低动量压实因子（低$alpha$）来减小束长会引起微束不稳定性，这一方面会导致有效束长的延长，从而成为 X 射线范围内的关键障碍，但另一方面，如果能够对其进行适当控制，也会为产生强烈的太赫兹辐射提供机会。在 KIT 的 KARA（卡尔斯鲁厄研究加速器）储存器中，计划在电子储存器中安装两块带有周期性矩形波纹的平行板。这两块板的几何形状会产生额外的纵向阻抗，从而影响电子束的动力学特性。由此产生的阻抗操纵将用于研究和控制纵向电子束动力学和发射的相干同步辐射（CSR）。本文以 KARA 储存环为例，介绍了模拟附加波纹板阻抗对纵向电子束动力学影响的系统研究结果。如果波纹板唤醒函数的周期性与纵向波束剖面中的子结构大小相匹配，就可以有效地控制不稳定阈值。这就将强太赫兹辐射扩展到了不同的束流状态。
{"title":"Simulation of the impact of an additional corrugated structure impedance on the bursting dynamics in an electron storage ring","authors":"Sebastian Maier, Miriam Brosi, Akira Mochihashi, Michael J. Nasse, Markus Schwarz, Anke-Susanne Müller","doi":"arxiv-2407.05828","DOIUrl":"https://doi.org/arxiv-2407.05828","url":null,"abstract":"In the case of single-digit picosecond bunch length, synchrotron light\u0000sources produce intense coherent radiation up to the THz range. The reduction\u0000of the bunch length by lowering the momentum compaction factor (low-$alpha$)\u0000gives rise to the micro-bunching instability, which is on one hand a crucial\u0000roadblock in the X-ray range during to the resulting effective bunch\u0000lengthening but on the other hand also an opportunity for the generation of\u0000intense THz radiation if it can be controlled appropriately. In the KIT storage\u0000ring KARA (Karlsruhe Research Accelerator), two parallel plates with periodic\u0000rectangular corrugations are planned to be installed in an electron storage\u0000ring. These plates create an additional longitudinal impedance based on their\u0000geometry, which can affect the beam dynamics. The resulting impedance\u0000manipulation will be used to study and control the longitudinal electron beam\u0000dynamics and the emitted coherent synchrotron radiation (CSR). This paper\u0000presents the results of systematic studies in simulation of the impact of\u0000additional corrugated plate impedances on the longitudinal beam dynamics using\u0000the example of the KARA storage ring. If the periodicity of the wake function\u0000of the corrugated plates matches the size of the substructures in the\u0000longitudinal bunch profile, the instability threshold can be effectively\u0000manipulated. This extends intense THz radiation to different beam current\u0000regimes.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141572450","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}
Bela Erdelyi, Kevin Hamilton, Jacob Pratscher, Marie Swartz
Nonlinear, completely integrable Hamiltonian systems that serve as blueprints for novel particle accelerators at the intensity frontier are promising avenues for research, as Fermilab's Integrable Optics Test Accelerator (IOTA) example clearly illustrates. Here, we show that only very limited generalizations are possible when no approximations in the underlying Hamiltonian or Maxwell equations are allowed, as was the case for IOTA. Specifically, no such systems exist with invariants quadratic in the momenta, precluding straightforward generalization of the Courant-Snyder theory of linear integrable systems in beam physics. We also conjecture that no such systems exist with invariants of higher degree in the momenta. This leaves solenoidal magnetic fields, including their nonlinear fringe fields, as the only completely integrable static magnetic fields, albeit with invariants that are linear in the momenta. The difficulties come from enforcing Maxwell equations; without constraints, we show that there are many solutions. In particular, we discover a previously unknown large family of integrable Hamiltonians.
{"title":"Nonexistence of Integrable Nonlinear Magnetic Fields with Invariants Quadratic in Momenta","authors":"Bela Erdelyi, Kevin Hamilton, Jacob Pratscher, Marie Swartz","doi":"arxiv-2407.04145","DOIUrl":"https://doi.org/arxiv-2407.04145","url":null,"abstract":"Nonlinear, completely integrable Hamiltonian systems that serve as blueprints\u0000for novel particle accelerators at the intensity frontier are promising avenues\u0000for research, as Fermilab's Integrable Optics Test Accelerator (IOTA) example\u0000clearly illustrates. Here, we show that only very limited generalizations are\u0000possible when no approximations in the underlying Hamiltonian or Maxwell\u0000equations are allowed, as was the case for IOTA. Specifically, no such systems\u0000exist with invariants quadratic in the momenta, precluding straightforward\u0000generalization of the Courant-Snyder theory of linear integrable systems in\u0000beam physics. We also conjecture that no such systems exist with invariants of\u0000higher degree in the momenta. This leaves solenoidal magnetic fields, including\u0000their nonlinear fringe fields, as the only completely integrable static\u0000magnetic fields, albeit with invariants that are linear in the momenta. The\u0000difficulties come from enforcing Maxwell equations; without constraints, we\u0000show that there are many solutions. In particular, we discover a previously\u0000unknown large family of integrable Hamiltonians.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141572452","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}
E. Bouquerel, T. Adama, C. Maazouzi, E. Traykov, P. Graehling, C. Mathieu
As a part of future developments of beam diagnostics, a low energy experimental bench (LEEx-B) has been recently designed, built and commissioned at IPHC-CNRS of Strasbourg. The bench is composed of a Cs+ ion gun installed on a HV platform and providing beams up to 25 keV. A beam profiler and an Allison-type emittance-meter allow the qualification of the setup and also the characterization of the beam. During the commissioning process, the electronics, and the control system were upgraded in order to push the limits towards low beam currents measured by the emittance-meter.
{"title":"LEEx-B: Low Energy Experimental Bench Development at IPHC-CNRS Strasbourg","authors":"E. Bouquerel, T. Adama, C. Maazouzi, E. Traykov, P. Graehling, C. Mathieu","doi":"arxiv-2407.02107","DOIUrl":"https://doi.org/arxiv-2407.02107","url":null,"abstract":"As a part of future developments of beam diagnostics, a low energy\u0000experimental bench (LEEx-B) has been recently designed, built and commissioned\u0000at IPHC-CNRS of Strasbourg. The bench is composed of a Cs+ ion gun installed on\u0000a HV platform and providing beams up to 25 keV. A beam profiler and an\u0000Allison-type emittance-meter allow the qualification of the setup and also the\u0000characterization of the beam. During the commissioning process, the\u0000electronics, and the control system were upgraded in order to push the limits\u0000towards low beam currents measured by the emittance-meter.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"59 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141526848","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}
Seeded Free Electron Lasers (FELs) demonstrate a good performance and are successfully used in different user experiments in extreme ultraviolet and soft X-ray regimes. In this paper a simple modification of the seeding scenario is proposed relying on generation of two closely spaced bunches with very different properties: a low-current seeding bunch, and a high-current bunch that amplifies coherent radiation, produced by the seeding bunch. This approach eliminates different limitations and mitigates some harmful effects in the standard scenario. In particular, one can generate very high harmonic numbers with a moderate laser power in a simple high-gain harmonic generation (HGHG) scheme. Alternatively, in case of moderate harmonic numbers, one can strongly reduce the required laser power thus simplifying design of high repetition rate seeded FELs. An influence of beam dynamics effects (like nonlinearities of the longitudinal phase space of electron beams, coherent synchrotron radiation, longitudinal space charge, geometrical wakefields, microbunching instabilities etc.) on properties of output radiation (spectrum broadening, pedestals, stability) can be to a large extent reduced in the proposed scheme. In this paper we illustrate the operation of the two-bunch seeding scheme in HGHG configuration with realistic start-to-end simulations for the soft X-ray user facility FLASH. We show that nearly Fourier-limited multi-gigawatt pulses can be generated at 4 nm using the present compact design of the undulator system. With several thousand pulses per second this can be a unique source for photon science.
有源自由电子激光器（FEL）具有良好的性能，并成功应用于不同用户的极紫外和软 X 射线实验中。本文提出了对播种方案的一个简单修改，即依靠产生两个具有截然不同特性的紧密间隔束：一个低电流播种束和一个放大由播种束产生的相干辐射的高电流束。这种方法可以消除不同的限制，并减轻标准方案中的一些有害影响。特别是，在简单的高增益谐波发生（HGHG）方案中，可以用中等激光功率产生非常高的谐波数。或者，在谐波数适中的情况下，可以大大降低所需的激光功率，从而简化高重复率 FEL 的设计。光束动力学效应（如电子束纵向相空间的非线性、相干同步辐射、纵向空间电荷、几何唤醒场、微束流不稳定性等）对输出辐射特性（频谱展宽、基座、稳定性）的影响在很大程度上可以通过建议的方案来降低。在本文中，我们通过对软 X 射线用户设施 FLASH 进行真实的端到端模拟，说明了双束播种方案在 HGHG 配置中的运行情况。我们的研究表明，利用目前紧凑型设计的起落架系统，可以在 4 纳米波长上产生近傅立叶限的多兆瓦脉冲。
{"title":"Two-bunch seeding of soft X-ray free electron lasers","authors":"E. Schneidmiller, I. Zagorodnov","doi":"arxiv-2406.19984","DOIUrl":"https://doi.org/arxiv-2406.19984","url":null,"abstract":"Seeded Free Electron Lasers (FELs) demonstrate a good performance and are\u0000successfully used in different user experiments in extreme ultraviolet and soft\u0000X-ray regimes. In this paper a simple modification of the seeding scenario is\u0000proposed relying on generation of two closely spaced bunches with very\u0000different properties: a low-current seeding bunch, and a high-current bunch\u0000that amplifies coherent radiation, produced by the seeding bunch. This approach\u0000eliminates different limitations and mitigates some harmful effects in the\u0000standard scenario. In particular, one can generate very high harmonic numbers\u0000with a moderate laser power in a simple high-gain harmonic generation (HGHG)\u0000scheme. Alternatively, in case of moderate harmonic numbers, one can strongly\u0000reduce the required laser power thus simplifying design of high repetition rate\u0000seeded FELs. An influence of beam dynamics effects (like nonlinearities of the\u0000longitudinal phase space of electron beams, coherent synchrotron radiation,\u0000longitudinal space charge, geometrical wakefields, microbunching instabilities\u0000etc.) on properties of output radiation (spectrum broadening, pedestals,\u0000stability) can be to a large extent reduced in the proposed scheme. In this\u0000paper we illustrate the operation of the two-bunch seeding scheme in HGHG\u0000configuration with realistic start-to-end simulations for the soft X-ray user\u0000facility FLASH. We show that nearly Fourier-limited multi-gigawatt pulses can\u0000be generated at 4 nm using the present compact design of the undulator system.\u0000With several thousand pulses per second this can be a unique source for photon\u0000science.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"93 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141509293","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}
Undulators are used in storage rings to produce extremely brilliant synchrotron radiation. In the ideal case, a perfectly tuned undulator always has a first and second field integrals equal to zero. But, in practice, field integral changes during gap movements can never be avoided for real-life devices. As they significantly impact the circulating electron beam, there is the need to routinely compensate such effects. Deep Neural Networks can be used to predict the distortion in the closed orbit induced by the undulator gap variations on the circulating electron beam. In this contribution several current state-of-the-art deep learning algorithms were trained on measurements from PETRA~III. The different architecture performances are then compared to identify the best model for the gap-induced distortion compensation.
{"title":"Neural Networks for ID Gap Orbit Distortion Compensation in PETRA III","authors":"Bianca Veglia, Ilya Agapov, Joachim Keil","doi":"arxiv-2406.17494","DOIUrl":"https://doi.org/arxiv-2406.17494","url":null,"abstract":"Undulators are used in storage rings to produce extremely brilliant\u0000synchrotron radiation. In the ideal case, a perfectly tuned undulator always\u0000has a first and second field integrals equal to zero. But, in practice, field\u0000integral changes during gap movements can never be avoided for real-life\u0000devices. As they significantly impact the circulating electron beam, there is\u0000the need to routinely compensate such effects. Deep Neural Networks can be used\u0000to predict the distortion in the closed orbit induced by the undulator gap\u0000variations on the circulating electron beam. In this contribution several\u0000current state-of-the-art deep learning algorithms were trained on measurements\u0000from PETRA~III. The different architecture performances are then compared to\u0000identify the best model for the gap-induced distortion compensation.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141509292","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}
We explain the algorithm employed in SHADOW4 to generate bending magnet sources. We provide an overview of the fundamental equations used to calculate the spectral and angular distributions of synchrotron emission from bending magnets. We outline the procedures for ray sampling. We present examples for intensity and polarization of the bending magnet at the old ESRF1 storage ring, and phase spaces for the bending magnet of the upcoming ALSU ring. Finally, we discuss the calculation of the effective source size and compare it with ray tracing.
{"title":"Ray tracing simulations of bending magnet sources with SHADOW4","authors":"Manuel Sanchez del Rio, Howard A. Padmore","doi":"arxiv-2406.16446","DOIUrl":"https://doi.org/arxiv-2406.16446","url":null,"abstract":"We explain the algorithm employed in SHADOW4 to generate bending magnet\u0000sources. We provide an overview of the fundamental equations used to calculate\u0000the spectral and angular distributions of synchrotron emission from bending\u0000magnets. We outline the procedures for ray sampling. We present examples for\u0000intensity and polarization of the bending magnet at the old ESRF1 storage ring,\u0000and phase spaces for the bending magnet of the upcoming ALSU ring. Finally, we\u0000discuss the calculation of the effective source size and compare it with ray\u0000tracing.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"99 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141526849","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}
Here, we introduce Linac_Gen, a tool developed at Fermilab, which combines machine learning algorithms with Particle-in-Cell methods to advance beam dynamics in linacs. Linac_Gen employs techniques such as Random Forest, Genetic Algorithms, Support Vector Machines, and Neural Networks, achieving a tenfold increase in speed for phase-space matching in linacs over traditional methods through the use of genetic algorithms. Crucially, Linac_Gen's adept handling of 3D field maps elevates the precision and realism in simulating beam instabilities and resonances, marking a key advancement in the field. Benchmarked against established codes, Linac_Gen demonstrates not only improved efficiency and precision in beam dynamics studies but also in the design and optimization of linac systems, as evidenced in its application to Fermilab's PIP-II linac project. This work represents a notable advancement in accelerator physics, marrying ML with PIC methods to set new standards for efficiency and accuracy in accelerator design and research. Linac_Gen exemplifies a novel approach in accelerator technology, offering substantial improvements in both theoretical and practical aspects of beam dynamics.
{"title":"Linac_Gen: integrating machine learning and particle-in-cell methods for enhanced beam dynamics at Fermilab","authors":"Abhishek Pathak","doi":"arxiv-2406.16630","DOIUrl":"https://doi.org/arxiv-2406.16630","url":null,"abstract":"Here, we introduce Linac_Gen, a tool developed at Fermilab, which combines\u0000machine learning algorithms with Particle-in-Cell methods to advance beam\u0000dynamics in linacs. Linac_Gen employs techniques such as Random Forest, Genetic\u0000Algorithms, Support Vector Machines, and Neural Networks, achieving a tenfold\u0000increase in speed for phase-space matching in linacs over traditional methods\u0000through the use of genetic algorithms. Crucially, Linac_Gen's adept handling of\u00003D field maps elevates the precision and realism in simulating beam\u0000instabilities and resonances, marking a key advancement in the field.\u0000Benchmarked against established codes, Linac_Gen demonstrates not only improved\u0000efficiency and precision in beam dynamics studies but also in the design and\u0000optimization of linac systems, as evidenced in its application to Fermilab's\u0000PIP-II linac project. This work represents a notable advancement in accelerator\u0000physics, marrying ML with PIC methods to set new standards for efficiency and\u0000accuracy in accelerator design and research. Linac_Gen exemplifies a novel\u0000approach in accelerator technology, offering substantial improvements in both\u0000theoretical and practical aspects of beam dynamics.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141509159","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}
Yongjun Li, Kiman Ha, Danny Padrazo, Bernard Kosciuk, Belkacem Bacha, Michael Seegitz, Robert Rainer, Joseph Mead, Xi Yang, Yuke Tian, Robert Todd, Victor Smaluk, Weixing Cheng
This paper reports recent lattice characterization results obtained at the National Synchrotron Light Source II (NSLS-II) storage ring, conducted without reliance on a lattice model. A pair of beam position monitors (BPMs) with bunch-by-bunch (B$times$B) resolution, were recently installed in a section of the storage ring free of magnetic fields. The new BPM pair measured the beam, or bunch's transverse Poincar'e map precisely after the beam was excited. Linear one-turn-matrices (OTM) were then derived, and from these, the 4-dimensional coupled Twiss parameters were extracted at the locations of the BPM pair. By normalizing beam oscillation amplitudes with the Twiss parameters, the global action-variables were obtained. These action-variables facilitated the measurement of the local Twiss parameters observed by other BPMs independent on lattice model. This method is general, and particularly useful in certain scenarios such as a round beam mode in a diffraction-limited light source ring. We applied it to assess both weakly and strongly coupled lattices at the NSLS-II ring. Through analysis of the strongly coupled lattice, the quadrupole tilt errors were estimated to be less than 400 si{mu}rad. Utilizing the BPMs' B$times$B resolution, for the first time we observed the variations of the linear lattice along a long bunch-train.
{"title":"Dedicated beam position monitor pair for model-independent lattice characterization at NSLS-II","authors":"Yongjun Li, Kiman Ha, Danny Padrazo, Bernard Kosciuk, Belkacem Bacha, Michael Seegitz, Robert Rainer, Joseph Mead, Xi Yang, Yuke Tian, Robert Todd, Victor Smaluk, Weixing Cheng","doi":"arxiv-2406.16660","DOIUrl":"https://doi.org/arxiv-2406.16660","url":null,"abstract":"This paper reports recent lattice characterization results obtained at the\u0000National Synchrotron Light Source II (NSLS-II) storage ring, conducted without\u0000reliance on a lattice model. A pair of beam position monitors (BPMs) with\u0000bunch-by-bunch (B$times$B) resolution, were recently installed in a section of\u0000the storage ring free of magnetic fields. The new BPM pair measured the beam,\u0000or bunch's transverse Poincar'e map precisely after the beam was excited.\u0000Linear one-turn-matrices (OTM) were then derived, and from these, the\u00004-dimensional coupled Twiss parameters were extracted at the locations of the\u0000BPM pair. By normalizing beam oscillation amplitudes with the Twiss parameters,\u0000the global action-variables were obtained. These action-variables facilitated\u0000the measurement of the local Twiss parameters observed by other BPMs\u0000independent on lattice model. This method is general, and particularly useful\u0000in certain scenarios such as a round beam mode in a diffraction-limited light\u0000source ring. We applied it to assess both weakly and strongly coupled lattices\u0000at the NSLS-II ring. Through analysis of the strongly coupled lattice, the\u0000quadrupole tilt errors were estimated to be less than 400 si{mu}rad.\u0000Utilizing the BPMs' B$times$B resolution, for the first time we observed the\u0000variations of the linear lattice along a long bunch-train.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141509294","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}
Attosecond x-ray pulses play a crucial role in the study of ultrafast phenomena occurring within inner and valence electrons. Especially isolated attosecond pulses with high photon energy and high peak power are of great significance in single-shot imaging in the soft x-ray region, life sciences, and attosecond pump-probe experiments. In modern accelerators, laser manipulation of electrons can be used to tailor the ultrafast properties of free-electron laser (FEL) pulses. In this paper, we propose a novel laser manipulation technique that makes use of two laser beams with mutual delays and tilted wavefronts to synthesize microbunching rotation on the scale of infrared laser wavelengths within the electron bunch for generating isolated attosecond soft x-ray pulses. This microbunching rotation ultimately leads to an enhanced current contrast ratio between the main peak and the surrounding satellite peaks within the bunch. By properly accounting for the longitudinal space charge fields within the FEL undulator, a tapered undulator can further suppress the side peaks in the radiation pulse and enable the selection of an isolated, hundred-attosecond, GW-level soft x-ray pulse.
阿秒 X 射线脉冲在研究发生在内层电子和价电子内部的超快现象中起着至关重要的作用。尤其是具有高光子能量和高峰值功率的孤立阿秒脉冲，在软 X 射线区域的单次成像、生命科学和阿秒泵探实验中具有重要意义。在现代加速器中，对电子的激光操纵可用于定制三电子激光（FEL）脉冲的超快特性。在本文中，我们提出了一种新颖的激光操纵技术，利用两束相互延迟和倾斜的激光波面，在电子束内合成红外激光波长尺度的微束旋转，以产生孤立的阿秒软 X 射线脉冲。这种微束旋转最终导致电子束内主峰与周围卫星峰之间的电流对比度增强。通过适当考虑 FEL 降频器内的纵向空间电荷场，锥形降频器可以进一步抑制辐射脉冲中的边峰，并能够选择隔离的、百毫秒级的 GW 级软 X 射线脉冲。
{"title":"Synthesis of Electron Microbunching Rotation for Generating Isolated Attosecond Soft X-ray Free-electron Laser Pulses","authors":"Hao Sun, Xiaofan Wang, Li Zeng, Weiqing Zhang","doi":"arxiv-2406.14843","DOIUrl":"https://doi.org/arxiv-2406.14843","url":null,"abstract":"Attosecond x-ray pulses play a crucial role in the study of ultrafast\u0000phenomena occurring within inner and valence electrons. Especially isolated\u0000attosecond pulses with high photon energy and high peak power are of great\u0000significance in single-shot imaging in the soft x-ray region, life sciences,\u0000and attosecond pump-probe experiments. In modern accelerators, laser\u0000manipulation of electrons can be used to tailor the ultrafast properties of\u0000free-electron laser (FEL) pulses. In this paper, we propose a novel laser\u0000manipulation technique that makes use of two laser beams with mutual delays and\u0000tilted wavefronts to synthesize microbunching rotation on the scale of infrared\u0000laser wavelengths within the electron bunch for generating isolated attosecond\u0000soft x-ray pulses. This microbunching rotation ultimately leads to an enhanced\u0000current contrast ratio between the main peak and the surrounding satellite\u0000peaks within the bunch. By properly accounting for the longitudinal space\u0000charge fields within the FEL undulator, a tapered undulator can further\u0000suppress the side peaks in the radiation pulse and enable the selection of an\u0000isolated, hundred-attosecond, GW-level soft x-ray pulse.","PeriodicalId":501318,"journal":{"name":"arXiv - PHYS - Accelerator Physics","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141526852","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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