6533b7d8fe1ef96bd126adee

RESEARCH PRODUCT

A simple method for counting the number of trapped ions in an ion trap

J. TanakaO. BeckerT. NakamuraM. WadaGünter WerthIchiro KatayamaD. SchnierShunsuke OhtaniK. OkadaF. ArbesHirokane KawakamiHans A. Schuessler

subject

PhysicsQuantum opticsSIMPLE (dark matter experiment)PhotonPhysics and Astronomy (miscellaneous)Other Fields of PhysicsGeneral EngineeringGeneral Physics and AstronomyIonPhysics::Plasma PhysicsMetastabilitySpontaneous emissionPhysics::Atomic PhysicsIon trapAtomic physics

description

The number of stored Ca\(^+\) ions in an ion trap was measured optically by utilizing the metastable states. All the ions trapped are first pumped into the metastable \(D\) states. The ions in the metastable \(D\) states are transferred to the ground \(S\) state via the \(P\) state by exciting a \(D\rightarrow P\) transition. Each ion then emits one photon through a subsequent \(P\rightarrow S\) spontaneous emission. Thus, the number of photons is the same as the number of trapped ions initially in the metastable states. When a fraction of all the stored ions are pumped into the metastable states, the method is still applicable if the fraction of the ions is known.

https://doi.org/10.1007/s003400050150