A quartz amplifier for high-sensitivity Fourier-transform ion-cyclotron-resonance measurements with trapped ions

Abstract

Single-ion sensitivity is obtained in precision Penning-trap experiments devoted to light (anti)particles or ions with low mass-to-charge ratios, by adding an inductance coil to an amplifier connected to the trap, both operated at 4 K. However, single-ion sensitivity has not been reached on heavy singly or doubly charged ions. In this publication, we present a new system to reach this point, based on the use of a quartz crystal as an inductance, together with a newly developed broad-band (BB) amplifier. We detect the reduced-cyclotron frequency of 40Ca+ ions stored in a 7-tesla open-ring Penning trap. By comparing the detected electric signal obtained with the BB amplifier and the fluorescence signal obtained by collecting the photons emitted by a trapped ion cloud, we show a detection limit below 110 ions. Adding the crystal, the electrical signal increases by a factor of about 30 at room temperature, which combined with the measured equivalent resistance and voltage noise, proves the feasibility of the system to reach single-ion sensitivity at 4 K.

Non-equilibrium Coupling of a Quartz Resonator to Ions for Penning-Trap Fast Resonant Detection

“…The experiments reported here have been carried out with the TRAPSENSOR openring Penning trap [18] and the quartz amplifier described in Ref. [9]. Calcium atoms are evaporated from an oven and collimated through a 1-mm diameter hole to reach an area close to the center of the trap, where they are photoionized using two laser beams (Fig.…”

“…with Very recently we have reported the first experimental results utilizing quartz resonators for measurements of ν + of stored 40 Ca + ions [9] using the Fourier-Transform Ion-Cyclotron-Resonance (FT-ICR) technique [10,11], and performed the first mass measurements using a quartz through a ν + measurement on 206,207 Pb + ions [12], using FT-ICR combined with classical avoided crossing [13]. In this publication we study the first coupling observed between trapped ions and a quartz resonator, even when the resonator is at room temperature.…”

“…When this coherence is lost during the thermalization of the crystal, the signal becomes a peak (right panel of Fig. 1) [9,12]. Both signals were obtained from the Fourier transformation of the power dissipated on a fixed input resistance.…”

Dynamics of an unbalanced two-ion crystal in a Penning trap for application in optical mass spectrometry

“…Nevertheless, using Eqs. (12) and (17), Ω + m = 3.00458 × Ω − m for a balanced crystal. In addition, from Fig.…”

“…Such an approach would also benefit precise mass measurements that are required in the context of neutrino physics where often the mass of rare isotopes, available only in limited samples, are demanded. The limitation in sen-sitivity of the Phase-Imaging Ion-Cyclotron-Resonance (PI-ICR) technique, currently in use at GSI-Darmstadt, to about 10 ions [10] motivated the development of new techniques [11,12].…”