First commissioning results of the waveguide RF Wien filter

Slim, J.

doi:10.1007/s10751-018-1547-6

Cited by 3 publications

(2 citation statements)

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“…• The radiofrequency Wien filter as a novel spin rotator has been proposed, commissioned and is in operation at COSY [343][344][345].…”

Section: Main Results Of Jedi Collaboration and Protonmentioning

confidence: 99%

General relativity effects in precision spin experimental tests of fundamental symmetries

Vergeles,

Nikolaev,

Obukhov

et al. 2022

Preprint

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A search for the P -and CP (T )-violating electric dipole moments (EDM) of atoms, particles and nuclei with sensitivity up to 10 −15 in units of the magnetic dipole moments, allowed by all discrete symmetries, is one of the topical problems of modern physics. According to Sakharov, CP -violation is one of the three key criteria of the baryogenesis in the generally accepted paradigm of the Big Bang cosmology. All three criteria are supported by the Standard Model, but it fails to describe quantitatively the observed baryon asymmetry of the Universe. This is regarded a strong argument in favor of the existence of CP -symmetry breaking mechanisms beyond the minimal Standard Model, which can lead to a measurable EDMs of atoms, particles and nuclei. Searches for the EDM via the spin rotation in electric fields are currently underway in dozens of laboratories worldwide. Direct searches for EDM of charged particles and nuclei are possible only in storage rings (COSY, NICA). After successful studies by the JEDI collaboration at the COSY synchrotron, at the forefront in the field is a search for the proton EDM in an electrostatic storage ring with the proton spin frozen at the magic energy with the projected sensitivity dp ∼ 10 −29 e•cm. The prototype storage ring PTR is proposed as a precursor to such a dedicated storage ring, with the prospect of the frozen proton spin ring becoming a part of the physics at CERN beyond the Large Hadron Collider program. Following a brief introduction to the CP -violation physics and the baryogenesis, the review presents a detailed discussion of significant contributions to the spin dynamics from the terrestrial gravity along with the new effects of Earth's rotation in ultrasensitive searches for the EDM of charged particles and neutrons. Quite remarkably, for the projected sensitivity to the proton EDM, these false EDM effects can by one to two orders of magnitude exceed the signal of the proton EDM, and become comparable to an EDM contribution in experiments with ultracold neutrons. We also discuss the role of a precessing spin as a detector of the axion-like dark matter, and consider applications of the quantum gravitational anomalies to the dense matter hydrodynamics and the spin phenomena in the non-central nuclear collisions.

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“…• The radiofrequency Wien filter as a novel spin rotator has been proposed, commissioned and is in operation at COSY [343][344][345].…”

Section: Main Results Of Jedi Collaboration and Protonmentioning

confidence: 99%

General relativity effects in precision spin experimental tests of fundamental symmetries

Vergeles,

Nikolaev,

Obukhov

et al. 2022

Preprint

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“…In 2018, the JEDI collaboration made a first-ever deuteron EDM measurement at COSY. Since in a non-Frozen Spin ring and EDM generates small-amplitude oscillations of the vertical beam polarization component (at the deuteron momentum 970 MeV/c used in COSY, the oscillation amplitude is on the level 3 • 10 −10 assuming an EDM d = 10 −24 e•cm), a resonance-type methodology was used [14,15], which uses a custom-design RF Wien filter [16,17] made specially for COSY.…”

Section: Introductionmentioning

confidence: 99%

2D Frozen spin method of searching for the deuteron EDM in a storage ring

Aksentev¹

2019

Preprint

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The purpose of the present work is the development of a method for searching the electric dipole moment (EDM) of the deuteron inside the storage ring environment using the frozen spin method. The 2D frozen spin method is a variation on the original frozen spin method proposed at Brookhaven National Laboratory, in which the beam polarisation vector freely precesses in the vertical plane. One distinguishing feature of the 2D frozen spin method, is that it uses the radial magnetic fields induced by the accelerator optical lattice's imperfections to drive the vertical plane precession. The net electric + magnetic dipole moment spin precession frequency is measured. The EDM estimator is constructed as the sum of the net frequency estimates in two cases: when the beam circulates clockwise (CW), and when it does counter-clockwise (CCW). For the deuteron, since the experiment is performed in a combined ring, the beam circulation direction change requires flipping the polarity of the guiding magnetic field. When this is done, the imperfection fields change their sign as well, and so does the magnetic dipole moment (MDM) component of the spin precession angular velocity vector. Therefore, theoretically, the MDM term cancels in the EDM estimator. The trick is to calibrate the MDM precession frequency with sufficient precision. For that purpose, the concept of the effective Lorentz factor was introduced. We try to prove that particles having equal values of the effective Lorentz factor have equal spin tunes (and invariant spin axis orientations as well), and therefore, by controlling a single parameter -- the effective Lorentz factor -- it is possible to calibrate the MDM component of the precession frequency. A special calibration procedure is numerically modelled, with the conclusion that it allows sufficiently precise MDM spin precession frequency reproduction. Three major systematic effects of spin dynamics have been analysed: 1) perturbations to the particle spin dynamics caused by betatron oscillations, 2) spin decoherence in the zero spin resonance (frozen spin) region, 3) properties of the machine imperfection MDM spin precession angular velocity. We conclude that the first systematic effect is negligible; analyse the sextupole field approach to suppressing spin decoherence, and find it effective; find that the imperfections systematic error is linear, but asymmetric with respect to the beam circulation direction, which is more motivation for using the effective Lorentz factor as the tool for calibrating the MDM spin precession frequency. Overall, we find the proposed method effective.

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