scholarly journals Polarization control in spin-transparent hadron colliders by weak-field navigators involving lattice enhancement effect

2021 ◽  
Vol 81 (11) ◽  
Author(s):  
Yu. N. Filatov ◽  
A. M. Kondratenko ◽  
M. A. Kondratenko ◽  
Ya. S. Derbenev ◽  
V. S. Morozov ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Closed Orbit ◽  
Hadron Collider ◽  
Beam Polarization ◽  
Enhancement Effect ◽  
Interaction Point ◽  
Polarization Control ◽  
High Energies ◽  
Orbit Perturbation ◽  
Hadron Polarization

AbstractHadron polarization control schemes for Spin Transparent (ST) synchrotrons are analyzed. The spin dynamics and beam polarization in such synchrotrons are controlled by spin navigators (SN) which are special small insertions of weak magnetic fields. An SN stabilizes the beam polarization and allows for setting any desirable spin orientation at an interaction point in the operational regime, including a frequent spin flip. We present a general approach to design of SNs. We distinguish different types of SNs, namely, those not causing closed orbit perturbation as well as those producing local and global orbit distortions. In the second case, the concept of the spin response function in an ST synchrotron is applied and expanded to reveal the effect of the SN strength enhancement by magnetic lattice of the synchrotron. We provide conceptual schemes for SN designs using longitudinal and transverse magnetic fields allowing for polarization control at low as well as high energies. We also develop the ST concept for ultra-high energies. This development may enable and stimulate interest in polarized beam experiments in possible polarized collider projects such as Large Hadron Collider (LHC), Future Circular Collider (FCC) and Super Proton Proton Collider (SPPC).

scholarly journals Spin transparency mode in the NICA collider

2019 ◽  
Vol 204 ◽  
pp. 10014 ◽  
Author(s):  
Yury Filatov ◽  
Alexander Kovalenko ◽  
Andrey Butenko ◽  
Evgeniy Syresin ◽  
Vladimir Mikhailov ◽  
...  
Keyword(s):  
Closed Orbit ◽  
Polarized Light ◽  
Beam Polarization ◽  
New Approach ◽  
Spin Mode ◽  
Polarization Control ◽  
Stable Orientation ◽  
Precision Level ◽  
Light Ions ◽  
Nica Collider

The NICA collider can operate with polarized light ions in two modes. At the Preferred Spin mode (PS mode) the periodic spin motion along the closed orbit is unique, i.e. the static magnetic lattice determines a single stable orientation of the beam polarization at any collider’'s place. At the Spin Transparency mode (ST mode) any spin direction repeats every particle turn along the closed orbit, i.e. the collider’s magnetic lattice is transparent to the spin. ST mode allows one to use a completely new approach to carry out experiments with polarized ions at high precision level. The features of ion polarization control in the ST mode are discussed. The schemes of polarization control in the NICA collider in the ST mode are presented.

scholarly journals Spin response function technique in spin-transparent synchrotrons

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Y. N. Filatov ◽  
A. M. Kondratenko ◽  
M. A. Kondratenko ◽  
Y. S. Derbenev ◽  
V. S. Morozov ◽  
...  
Keyword(s):  
Response Function ◽  
Orbital Motion ◽  
Spin Dynamics ◽  
Function Technique ◽  
Beam Polarization ◽  
Spin Motion ◽  
Direct Relevance ◽  
Polarization Control ◽  
Orbit Perturbation ◽  
Spin Response

Abstract Small perturbative fields in a synchrotron influence both the spin and orbital motion of a stored beam. Their effect on the beam polarization consists of two contributions, a direct kick and an effect of the ring lattice due to orbit perturbation. Spin response function is an analytic technique to account for both contributions. We develop such a technique for the spin-transparent synchrotrons where the design spin motion is degenerate. Several perspective applications are illustrated or discussed. In particular, we consider the questions of the influence of lattice imperfections on the spin dynamics and spin manipulation during an experiment. The presented results are of a direct relevance to NICA (JINR), RHIC (BNL), EIC (BNL) and other existing and future colliders when they arranged with polarization control in the spin-transparent mode.

scholarly journals Magnetic Field in Nuclear Collisions at Ultra High Energies

Physics ◽  
2019 ◽  
Vol 1 (2) ◽  
pp. 183-193
Author(s):  
Vitalii A. Okorokov
Keyword(s):  
Magnetic Field ◽  
Hard Sphere ◽  
W Boson ◽  
Hadron Collider ◽  
High Energy ◽  
Hard Sphere Model ◽  
Heavy Nuclei ◽  
Proton Proton ◽  
High Energies ◽  
The Magnetic Field

The magnetic field created in proton–proton and nucleus–nucleus collisions at ultra-high energies are studied with models of point-like charges and hard sphere for distribution of the constituents for vacuum conditions. The various beam ions are considered from light to heavy nuclei at energies corresponding to the nominal energies of the proton beam within the projects of further accelerator facilities high-energy Large Hadron Collider (HE-LHC) and Future Circular Collider (FCC). The magnetic-field strength immediately after collisions reaches the value tens of GeV 2 , while in the approach with point-like charges, some overestimate the amplitude of the field in comparison with more realistic hard-sphere model. The absolute value of the magnetic field rapidly decreases with time and increases with growth of atomic number. The amplitude for e B is estimated at level 100 GeV 2 to provide magnitude for quark–quark collisions at energies corresponding to the nominal energies of proton beams. These estimations are close to the range for onset of W boson condensation.

Design studies for the next generation electron ion colliders

2014 ◽  
Vol 29 (09) ◽  
pp. 1450053
Author(s):  
Hisham Kamal Sayed ◽  
S. A. Bogacz ◽  
G. Krafft
Keyword(s):  
Electron Beam ◽  
Numerical Study ◽  
Polarization Vector ◽  
Beam Polarization ◽  
Straight Section ◽  
Next Generation ◽  
Interaction Point ◽  
Accelerator Facility ◽  
Electron Ring ◽  
Betatron Motion

The next generation Electron Ion Collider (EIC) at Thomas Jefferson National Accelerator Facility (JLAB) utilizes a figure-8 shaped ion and electron rings. EIC has the ability to preserve the ion polarization during acceleration, where the electron ring matches in footprint with a figure-8 ion ring. The electron ring is designed to deliver a highly polarized high luminous electron beam at interaction point (IP). The main challenges of the electron ring design are the chromaticity compensation and maintaining high beam polarization of 70% at all energies 3–11 GeV without introducing transverse orbital coupling before the IP. The very demanding detector design limits the minimum distance between the final focus quadrupole and the interaction point to 3.5 m which results in a large β function inside the final focus quadrupoles leading to increased beam chromaticity. In this paper, we present a novel chromaticity compensation scheme that mitigates IP chromaticity by a compact chromaticity compensation section with multipole magnet components. In addition, a set of spin rotators are utilized to manipulate the polarization vector of the electron beam in order to preserve the beam polarization. The spin rotator solenoids introduce undesired coupling between the horizontal and vertical betatron motion of the beam. We introduce a compact and modular orbit decoupling insert that can fit in the limited space of the straight section in the figure-8 ring. We show a numerical study of the figure-8 ring design with the compact straight section, which includes the interaction region, chromaticity compensation section, and the spin rotators, the figure-8 design performance is evaluated with particle tracking.

scholarly journals Adaptive feedforward control of closed orbit distortion caused by fast helicity-switching undulators

2021 ◽  
Vol 28 (6) ◽  
Author(s):  
Mitsuhiro Masaki ◽  
Hirokazu Maesaka ◽  
Kouichi Soutome ◽  
Shiro Takano ◽  
Takahiro Watanabe ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Light Source ◽  
Feedforward Control ◽  
Closed Orbit ◽  
Repetition Period ◽  
Correction Algorithm ◽  
Error Sources ◽  
Actual Operation ◽  
Adaptive Feedforward

A new correction algorithm for closed orbit distortion based on an adaptive feedforward control (AFC) has been developed. At SPring-8, two helicity-switching twin-helical undulators (THUs) had been implemented with conventional feedforward corrections. However, the validity of these corrections turned out to be expiring due to unforeseen variation in the error magnetic fields with time. The developed AFC system has been applied to the THUs dynamically updating the feedforward table without stopping the helicity switching amid user experiments. The error sources in the two THUs are successfully resolved and corrected even while the two THUs are switching simultaneously with the same repetition period. The actual operation of the new AFC system enables us to keep the orbit variations suppressed with an accuracy at the sub-micrometre level in a transparent way for light source users.

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