Space-charge effects in Penning ion traps

Abstract

International audienceThe influence of space-charge on ion cyclotron resonances and magnetron eigenfrequency in a gas-filled Penning ion trap has been investigated. Off-line measurements with 39 K + using the cooling trap of the WITCH retardation spectrometer-based setup at ISOLDE / CERN were performed. Experimental ion cyclotron resonances were compared with ab initio Coulomb simulations and found to be in agreement. As an important systematic effect of the WITCH experiment , the magnetron eigenfrequency of the ion cloud was studied under increasing space-charge conditions. Finally , the helium buffer gas pressure in the Penning trap was determined by comparing experimental cooling rates with simulations