Achievements

Storage ring to search for electric dipole moments of charged particles: Feasibility study

This feasibility study - published as CERN Yellow Report - summarizes the achievements from the last years and presents a path towards a final ring.

First detection of collective oscillations of a stored deuteron beam with an amplitude close to the quantum limit

We investigated coherent betatron oscillations of a deuteron beam in the storage ring cooler synchrotron and storage ring, excited by a detuned rf Wien filter (WF). We demonstrate that the amplitudes of the zero-point (ground state) betatron oscillations of individual particles are only a factor of about 10 larger than the Heisenberg uncertainty limit.

EDM Precursor Run II: First electric dipole moment measurement of the deuteron with the waveguide RF Wien Filter

The second precursor run took place in spring 2021. Several improvements had been applied before and during the run.

Beam-based alignment at the Cooler Synchrotron COSY as a prerequisite for an electric dipole moment measurement

In order to reach highest accuracy for an EDM measurement, one has to know the exact trajectory through the magnets, especially the quadrupoles, to avoid the influence of magnetic fields on the polarization vector.

EDM Precursor Run I: First electric dipole moment measurement of the deuteron with the waveguide RF Wien Filter

After the preporatory work (polarimetry, spin coherence time, phase lock feedback, rf Wien filter, supercondicting solenoid) has been completed in previous beam times, in November 2018 we performed a first experiment to map the rf Wien filter resonance strength as function of artificial tilts of the invariant spin axis in perpendicular and longitudinal direction w.r.t. the beam direction.

A new beam polarimeter at COSY to search for electric dipole moments of charged particles

A calorimetric polarimeter based on inorganic LYSO scintillators has been designed for use in a storage ring to search for electric dipole moments (EDM) of charged particles such as the proton and deuteron.

Influence of electron cooling on the polarization lifetime of a horizontally polarized storage ring beam

We have shown previously, that the in-plane polarization (IPP) component of a polarized 0.97-GeV/c deuteron beam in the COSY storage ring may acquire a polarization half-life in excess of 1000 s. Here we discuss further tests pointing to additional gains in the IPP lifetime if cooling is permanently active.

Measurement of deuteron carbon vector analyzing powers in the kinetic energy range 170-380 MeV

A measurement of vector analyzing powers in elastic deuteron-carbon scattering has been performed at the Cooler Synchrotron COSY of Forschungszentrum Jülich, Germany necessary for polarimetry of future electric dipole moment searches at storage rings.

Phase Measurement for Driven Spin Oscillations in a Storage Ring

In this work we report the first simultaneous measurement of the horizontal and vertical components of the polarization vector in a storage ring under the inuence of a radio frequency (rf) solenoid.

Connection between zero chromaticity and long in-plane polarization lifetime in a magnetic storage ring

In this work, we demonstrate the connection between a magnetic storage ring with additional sextupole fields set so that the x and y chromaticities vanish and the maximizing of the lifetime of in-plane polarization (IPP) for a 0.97-GeV/c deuteron beam.

Phase Locking the Spin Precession in a Storage Ring

The successful use of feedback from a spin polarization measurement to the revolution frequency of a 0.97GeV/c bunched and polarized deuteron beam in the Cooler Synchrotron (COSY) storage ring has been realized in order to control both the precession rate (≈ 120kHz) and the phase of the horizontal polarization component.

Spin tune mapping as a novel tool to probe the spin dynamics in storage rings

We developed a new method based on the spin tune response of a machine to artificially applied longitudinal magnetic fields. This novel technique, called spin tune mapping, emerges as a very powerful tool to probe the spin dynamics in storage rings.

How to Reach a Thousand-Second in-Plane Polarization Lifetime with 0.97 GeV/c Deuterons in a Storage Ring

A deuteron beam polarization lifetime near 1000 seconds in the horizontal plane of the magnetic storage ring COSY has been acchieved. This record lifetime is required for a storage ring search for an intrinsic electric dipole moment on the deuteron at a statistical sensitivity level approaching 10-29 e∙cm.

New Method for a Continuous Determination of the Spin Tune in Storage Rings and Implications for Precision Experiments

A new method to determine the spin tune was established and tested as a precision tool for accelerator physics: controlling the spin motion of particles to high precision is mandatory, in particular, for the measurement of electric dipole moments of charged particles in a storage ring.

Last Modified: 01.07.2022