Polarized Ion Beams Research Articles

Die Erzeugung von negativen polarisierten Deuteriumionen aus metastabilen Deuteriumatomen im 2S 1/2-Zustand

An experimental method to produce polarized negative hydrogen ions is discussed and compared with other methods. The method makes use of the different lifetimes of the metastable 2S 1/2 state and the 2P 1/2 state of the hydrogen atom. Polarized ion beams are obtained by using a selective quenching process followed by selective ionisation. Experimental results are given for the intensity and polarization of the polarized negative ion beam of deuterons. These results were obtained as a function of the quenching-field, the magnetic field in the argon-cell and the density of argon and cesium. The yield of negative ions can be expressed by the cross sections for the different charge exchange reactions in argon. The measured tensorpolarisationP33 can be interpreted as a function of the cross sections, the argon-density and the magnetic field along the beam axis. Beams of 50 nA intensity were produced with a polarization ofP33=−0.250±0.006. The main advantage of this method is a low beam emittance, values of 0.7 cm rad eV1/2 were achieved. The production of a polarized positive deuteron beam seems to be possible.

New charge exchange reactions for production of polarized positive hydrogen ions

From considerations concerning the potential curves of ion systems like X −+ H +, some charge exchange reactions are supposed to be able to produce polarized positive hydrogen ions selectively from metastable H(2S) atoms. Charge exchange reactions with H 2, D 2 and He were investigated and the tensor polarization was measured. For polarized ion beam applications these reactions have the advantage of high cross sections.

Lamb‐Effect Sources Make Better Polarized Ion Beams

Spin dependence of nuclear forces is probably becoming more accessible to experiment as makers of polarized ion beams improve their sources. Two methods appear to be battling for the honor of producing the most intense and best polarized beams. The “conventional” one throws out ground‐state atoms you don't want with inhomogeneous magnetic fields and keeps the ones you do want.