Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 1811.12595

Experimental Investigation of the Transition Energy $γ_t$ in the Isochronous Mode of the HIRFL-CSRe

W. W. Ge·Y. J. Yuan·J. C. Yang·R. J. Chen·X. L. Yan·H. Du·Z. S. Li·J. Yang·D. Y. Yin·L. J. Mao·X. N. Li·W. H. Zheng·G. D. Shen·B. Wu·S. Ruan·G. Wang·H. Zhao·M. Wang·M. Z. Sun·Y. M. Xing·P. Zhang·C. Y. Fu·P. Shuai·X. Xu·Y. H. Zhang·T. Bao·X. C. Chen·W. J. Huang·H. F. Li·J. H. Liu·Yu. A. Litvinov·S. Litvinov·Q. Zeng·X. Zhou
View original source ↗Read source document ↗Export metadata ↓

Abstract

The Isochronous Mass Spectrometry (IMS) based on storage rings is a powerful technique for mass measurement of short-lived exotic nuclei. The transition energy $γ_t$ of the storage ring is a vital parameter of the IMS technique. It is difficult to measure the $γ_t$ and its relation to momentum spread or circulating length, especially to monitor the variation of $γ_t$ during experiments. An experimental investigation on the $γ_t$ has been performed for the IMS experiment at the Cooler Storage Ring of the Heavy Ion Research Facility in Lanzhou (HIRFL-CSRe). With the velocity measured by two time-of-flight (TOF) detectors, the $γ_t$ as a function of orbital length can be determined. The influences of higher order magnetic field components on the $γ_t$ function were inferred for isochronous correction. This paper introduces and investigates the influence of dipole magnetic fields, quadrupole magnetic fields and sextupole magnetic fields on the $γ_t$ function. With the quadrupole magnets and sextupole magnets corrections, a mass resolution of 171332 (FWHM) and $σ(T)/T=1.34\times10^{-6}$ were reached, which shall be compared with 31319 (FWHM) and $σ(T)/T=7.35\times10^{-6}$ obtained without correction.

Explore related subjects

physics.acc-ph

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

W. W. Ge, Y. J. Yuan, J. C. Yang, R. J. Chen, X. L. Yan, H. Du, Z. S. Li, J. Yang, D. Y. Yin, L. J. Mao, X. N. Li, W. H. Zheng, G. D. Shen, B. Wu, S. Ruan, G. Wang, H. Zhao, M. Wang, M. Z. Sun, Y. M. Xing, P. Zhang, C. Y. Fu, P. Shuai, X. Xu, Y. H. Zhang, T. Bao, X. C. Chen, W. J. Huang, H. F. Li, J. H. Liu, Yu. A. Litvinov, S. Litvinov, Q. Zeng, X. Zhou. 2018-11-30. Experimental Investigation of the Transition Energy $γ_t$ in the Isochronous Mode of the HIRFL-CSRe. https://doi.org/10.1016/j.nima.2018.08.059

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Approximate solution of an adapted Bethe transport equation for electron scattering in foils

A new semi-analytical model for electron scattering in foils is presented valid for thin foils and electron-beam kinetic energies up to roughly $100$ keV and from 20 keV at a dimensionless foil thickness of $20$, and higher energies for thinner foils. To perform calculations, an approximate solution is constructed by Hankel transforms of an adapted Bethe transport equation for electron scattering. The Wentzel differential cross section is used in the Bethe transport Eq. and resulting integrals are solved analytically or approximated. These approximate solutions of the transport Eq.'s were compared to the Goudsmit-Saunderson solutions in gold, for thin samples with dimensionless thicknesses $λ=5,10,20$. We also compare to the Kawrakow \cite{Kawr} model, which uses the small angle approximation. We show that in the regime of $20$ to $100$ keV beam energies, our model performs better than Kawrakow's model and this is opposite above about 100 keV. Exactly, some angularly distributed beams and the influence of energy loss of the beam can be simulated with our model.

physics.acc-ph↗
arXiv2026

Reconstruction of Beam Transverse Parameters in the Fermilab Side-Coupled Linac Using a Normalized Coordinate Framework

Quadrupole scans are a commonly used tool for beam second moment reconstruction. Limitations in the strength of the magnets and layout of the beamline elements frequently preclude simple quadrupole-drift-detector scans from collecting sufficient data for reconstruction. Using a normalized coordinate framework, we characterize the prerequisites for a robust simple quadrupole scan and expand these prerequisites to reconstruction from more complex optics. The beam second moments are investigated at two locations in the Fermilab Side-Coupled Linac under simple and complex optics, using this framework to maximize information gained from wire scanner profile measurements.

physics.acc-ph↗
arXiv2026

Impedance of multilayer cylindrical structures with a material-filled beam region

Beam-coupling impedances in material media are relevant for ionization-cooling channels of a future muon collider, where the beam propagates in matter rather than vacuum. We extend the cylindrical field-matching formalism for multilayer structures to the case of a material-filled beam region surrounded by external layers with arbitrary electromagnetic properties. Relative to the vacuum formulation, the usual factor $1/γ^2$ is replaced by the material-dependent factor $F=1/\varepsilon_1-μ_1β^2$, and the radial propagation constant is modified accordingly. Analytical expressions are obtained for the monopolar longitudinal and dipolar transverse impedances, with the surrounding structure encoded through reflection coefficients determined by field matching. The formalism reduces to the known vacuum and perfectly conducting limits in the appropriate cases. Representative calculations are presented for absorber-relevant configurations, illustrating the dependence on the material properties of both the beam region and the surrounding layers. In particular, a finite beam-region conductivity can generate a real impedance component and reverse the sign of the imaginary space-charge impedance, while sufficiently high permittivity can give rise to resonant structures associated with oscillatory radial fields. The effect of finite-conductivity surroundings is also examined, showing the approach towards the perfectly conducting limit as the external conductivity is increased. The applicability of the infinite-length approximation is also discussed by comparison with finite-length mode-matching results.

physics.acc-ph↗