A compact design for a magnetic synchrotron to store beams of hydrogen atoms

Abstract

We present a design for an atomic synchrotron consisting of 40 hybrid magnetic hexapole lenses arranged in a circle. We show that for realistic parameters, hydrogen atoms with a velocity up to 600 m s −1 can be stored in a 1 m diameter ring, which implies that the atoms can be injected in the ring directly from a pulsed supersonic beam source. This ring can be used to study collisions between stored hydrogen atoms and supersonic beams of many different atoms and molecules. The advantage of using a synchrotron is two-fold: (i) the collision partners move in the same direction as the stored atoms, resulting in a small relative velocity and thus a low collision energy, and (ii) by storing atoms for many round-trips, the sensitivity to collisions is enhanced by a factor of 100-1000. In the proposed ring, the cross-sections for collisions between hydrogen, the most abundant atom in the universe, with any atom or molecule that can be put in a beam, including He, H 2 , CO, ammonia and OH can be measured at energies below 100 K. We discuss the possibility of using optical transitions to load hydrogen atoms into the ring without influencing the atoms that are already stored. In this way it will be possible to reach high densities of stored hydrogen atoms.

A detailed account of the measurements of cold collisions in a molecular synchrotron

“…Note that if the velocities of the beams are more similar, the energy resolution will also be improved [36], ultimately limited to the temperature of the stored ammonia packets. Finally, collision studies with paramagnetic atoms and molecules, such as hydrogen – the most abundant atom in the universe – can be performed in a magnetic synchrotron, as described in Van der Poel et al [46].…”

Quantum-State Control and Manipulation of Paramagnetic Molecules with Magnetic Fields

“…While electrostatic quadrupole and hexapole guides have seen widespread adoption with a range of polar molecules, the equivalent magnetic guides have focused largely on paramagnetic atomic species (19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32).…”

A magnetic guide to purify radical beams

“…Similar arrays have been employed to improve the transverse confinement of particles in between Zeeman-deceleration stages 22 and are proposed in a design for a hydrogen storage ring. 23 Here, we take inspiration from previous work 19 and propose a novel magnetic guide: using Halbach arrays to deflect and collimate the decelerated particles off the main beam axis and around an on-axis blade that stops any faster or undeflected species, before returning the decelerated species back to the main beam axis again. Such a design increases both the practicality and flexibility of the guide.…”