Jamal S. Slim

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 is described and tested. In an ideal planar magnetic ring, the spin tune-defined as the number of spin precessions per turn-is given by ν(s)=γG (γ is the Lorentz factor, G the gyromagnetic anomaly). At 970  MeV/c, the deuteron spins coherently precess at a frequency of ≈120  kHz in the Cooler Synchrotron COSY. The spin tune is deduced from the up-down asymmetry of deuteron-carbon scattering. In a time interval of 2.6 s, the spin tune was determined with a precision of the order 10^{-8}, and to 1×10^{-10} for a continuous 100 s accelerator cycle. This renders the presented method a new 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.

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

Precision experiments, such as the search for electric dipole moments of charged particles using storage rings, demand for an understanding of the spin dynamics with unprecedented accuracy. The ult ...

Conceptualization, design and simulation of a hybrid antenna system as a simultaneous RF hyperthermia applicator at 600 MHz and RF coil for Magnetic Resonance Imaging at 3 Tesla

This paper presents the conceptualization, design and simulation of a hybrid multi-frequency antenna system for Radio Frequency (RF) hyperthermia and Magnetic Resonance Imaging (MRI) applications with ultra-sharp hotspot. Two different bowtie antenna arrays have been designed, simulated and integrated. The first antenna array is designed as an RF coil for MR imaging. It is optimized to generate a highly homogeneous transmit B⃗1+ field and is intended for 3 T MRI systems. This corresponds to a frequency of 128 MHz. The second array aims to induce heat by accumulating the electromagnetic energy at one location thereby forming a hotspot. The operating frequency of the second system is 600 MHz. The computed homogeneity of the B1+ field generated by the imaging antennas shows similar values compared to a birdcage coil at the same frequency. The size of the hotspot generated by the heating subsystem was 26 × 26 × 93 mm3. The heating produced by the MR imaging antennas was negligible, compared to the RF hyperthermia applicator.

Towards a High-Accuracy RF Wien Filter for Spin Manipulation at COSY Jülich

The JEDI collaboration is aiming for electric dipole moment (EDM) measurements of deuterons and protons at COSY-Jülich. A high accuracy RF Wien filter, operating at the spin harmonic frequencies is planned to be integrated in the COSY ring at the Forschungszentrum Jülich. This RF Wien filter is intended for spin tune modulation purposes allowing to perform EDM measurements. Because of the smallness of the EDM signal, critical requirements on this Wien filter have been imposed both in terms of field homogeneity and orthogonality. The transverse electromagnetic (TEM) mode of a parallel-plates waveguide fulfills the requirements. This work will show both the electrodynamics analysis together with the engineering design.

Phase measurement for driven spin oscillations in a storage ring

This paper reports the first simultaneous measurement of the horizontal and vertical components of the polarization vector in a storage ring under the influence of a radio frequency (rf) solenoid. ...