S. Araki, Y. Higashi, Y. Honda, Y. Kurihara, M. Kuriki, T. Okugi, T. Omori, T. Taniguchi, N. Terunuma, J. Urakawa, X. Artru, M. Chevallier, V. Strakhovenko, E. Bulyak, P. Gladkikh, K. Moenig, R. Chehab, A. Variola, F. Zomer, S. Guiducci, P. Raimondi, F. Zimmermann, K. Sakaue, T. Hirose, M. Washio, N. Sasao, H. Yokoyama, M. Fukuda, K. Hirano, M. Takano, T. Takahashi, H. Sato, A. Tsunemi, J. Gao, V. Soskov
We describe a scheme for producing polarised positrons at the ILC from polarised X-rays created by Compton scattering of a few-GeV electron beam off a CO2 or YAG laser. This scheme is very energy effective using high finesse laser cavities in conjunction with an electron storage ring.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
继续探索
Positron sources are critical components of the future linear collider projects. This is essentially due to the high luminosity required, orders of magnitude higher than existing ones. In addition, polarization of the positron beam rather expands the physics research potential of the machine. In this framework, the Compton sources for polarized positron production are taken into account where the high energy gamma rays are produced by the Compton scattering and subsequently converted into the polarized electron-positron pairs in a target-converter. The Compton multiple Interaction Point (IP) l…
Electron storage rings of GeV energy with laser pulse stacking cavities are promising intense sources of polarised hard photons which, via pair production, can be used to generate polarised positron beams. Dynamics of electron bunches circulating in a storage ring and interacting with high-power laser pulses is studied both analytically and by simulation. Common features and differences in the behaviour of bunches interacting with an extremely high power laser pulse and with a moderate pulse are discussed. Also considerations on particular lattice designs for Compton gamma rings are presented.
If a beam of unpolarized positrons (which is considered as a sum of two fractions with opposite helicities) passes through an intense circular polarized laser radiation these fractions may be separated. For high laser flash intensity each positron will interact with $k_0\gg$1 laser photons subsequently (linear multiple compton scattering process). Due to difference in the compton cross-section for positrons polarized in opposite directions the mean final energy of each fraction will be different. It allows to get a polarized positron beam using the momentum selection (with some intensity loss)…
We propose a method for polarising antiprotons in a storage ring by means of a polarised positron beam moving parallel to the antiprotons. If the relative velocity is adjusted to $v/c \approx 0.002$ the cross section for spin-flip is as large as about $2 \cdot 10^{13}$ barn as shown by new QED-calculations of the triple spin-cross sections. Two possibilities for providing a positron source with sufficient flux density are presented. A polarised positron beam with a polarisation of 0.70 and a flux density of approximately $1.5 \cdot 10^{10}$/(mm$^2$ s) appears to be feasible by means of a radio…
The physics potential of an e+e- linear collider can be significantly enhanced if both the electron and positron beams are polarised. Low energy running at the Z-resonance or close to the W-pair threshold is particularly attractive with polarised positrons. This note discusses the experimental aspects and physics opportunities of both low energy running and positron polarisation.
In a number of papers an attractive method of laser polarization of electrons (positrons) at storage rings or linear colliders has been proposed. We show that these suggestions are incorrect and based on errors in simulation of multiple Compton scattering and in calculation of the Compton spin-flip cross sections. We argue that the equilibrium polarization in this method is zero.
To achieve the physics goals of future Linear Colliders, it is important that electron and positron beams are polarized. The positron source planned for the International Linear Collider (ILC) is based on a helical undulator system and can deliver a polarised beam with positron polarization of 60%. To ensure that no significant polarization is lost during the transport of the electron and positron beams from the source to the interaction region, spin tracking has to be included in all transport elements which can contribute to a loss of polarization. These are the positron source, the damping …
The beam energy measurement system for the VEPP-2000 electron-positron collider is described. The method of Compton backscattering of $CO$ laser photons on the electron beam is used. The relative systematic uncertainty of the beam energy determination is estimated as 6\cdot10^{-5}. It was obtained through comparison of the results of the beam energy measurements using the Compton backscattering and resonance depolarization methods.
For a number of physical studies which are planned to be made with the next generation colliders, it is necessary to use polarized beams of both electrons and positrons. The problem of producing and acceleration of polarized electrons may be considered to be solved, but the existing approaches to create polarized positron beams do not ensure the parameters required. This work proposes a new approach to produce polarized positron beams, which is based on the process of multiple Compton backscattering of unpolarized ultrarelativistic positrons in the field of intense circularly polarized laser w…
The new method for producing of the polarized relativistic positrons is suggested. A beam of unpolarized positrons accelerated up to a few GeV can be polarized during a head-on collision with an intense circularly polarized lazer wave. After a multiple Compton backscattering process the initial positrons may lose a substantial part of its energy and, as consequence, may acquire the significant longitudinal polarization. The simple formulas for the final positron energy and polarization degree depended on the laser flash parameters have been obtained. The comparison of efficiences for the sugge…
The circularly polarized gamma-quanta with energy > 10 MeV are formed during Compton backscattering of circularly polarized laser photons on an electron beam with energy 1.26 GeV. The contribution of nonlinear processes for planned parameters of a laser flash[T. Okugi, Y. Kurihara and M. Chiba, Jpn. J. Appl. Phys. 35, p. 3677 (1996).] can be rather significant, that leads to deterioration of polarization of a resulting gamma-beam. The direct method of measurement of gamma-beam circular polarization will allow not only to estimate a correctness of the theoretical calculations, but also to use t…
The review of using of compton backscattering method for determination of the beam energy in collider experiments is given.
Compton scattering provides one of the most promising scheme to obtain polarized positrons for the next generation of $e^-$ -- $e^+$ colliders. Moreover it is an attractive method to produce monochromatic high energy polarized gammas for nuclear applications and X-rays for compact light sources. In this framework a four-mirror Fabry-Pérot cavity has been installed at the Accelerator Test Facility (ATF - KEK, Tsukuba, Japan) and is used to produce an intense flux of polarized gamma rays by Compton scattering \cite{ipac-mightylaser}. For electrons at the ATF energy (1.28 GeV) Compton scattering …
As part of the R&D toward the production of high flux of polarised Gamma-rays we have designed and built a non-planar four-mirror optical cavity with a high finesse and operated it at a particle accelerator. We report on the main challenges of such cavity, such as the design of a suitable laser based on fiber technology, the mechanical difficulties of having a high tunability and a high mechanical stability in an accelerator environment and the active stabilization of such cavity by implementing a double feedback loop in a FPGA.
The beam energy measurement system (BEMS) for the upgraded Beijing electron-positron collider BEPC-II is described. The system is based on measuring the energies of Compton back-scattered photons. The relative systematic uncertainty of the electron and positron beam energy determination is estimated as 2 \cdot 10^{-5}. The relative uncertainty of the beam's energy spread is about 6 %.
Enhancing 10 TeV $γγ$-collider luminosity through scattering-laser wavelength selection in the presence of prolific electron-positron pair production
该研究针对10 TeV双光子对撞机，考虑正负电子对产生的自然限制与康普顿光子角发散，通过选择250 nm和1.25 nm散射激光波长增强其亮度，且次级正负电子对可用于重粒子产生研究。
A high-intensity laser-based positron source
本文提出一种基于高能电子束与高强激光脉冲对撞的正电子源，利用多光子Compton和Breit-Wheeler过程产生低发散度正电子，其亚微米级低发射度特性对对撞机应用极具吸引力。
扫码添加微信好友，提出您的宝贵建议 👇
💡 备注请填写：网站反馈
发表机构由 AI 从论文文本抽取，如发现错误，欢迎反馈修正建议。