Related Experiment Video
Updated: Jun 18, 2026

Preparing an Isotopically Pure 229Th Ion Beam for Studies of 229mTh
Published on: May 3, 2019
Two stability islands of quadrupole mass filter near q = 0.9 created by auxiliary radio frequency voltage
Chan Luo1, Gongyu Jiang, Nikolai V Konenkov
1Department of Chemistry, Fudan University, 220 Handan Road, Shanghai, 200433, China.
Abstract:
We report the numerical investigations of quadrupole mass filters concerning stability islands created by auxiliary radio frequency (RF) voltage with high and low frequencies near q = 0.9. The islands are located along the q axis near boundary value q = 0.908 with a low a parameter. The analysis is based upon the matrix method for stability diagram calculations and ion trajectory numerical simulation. The trajectory of ion motions is generated using Runge-Kutta-Nystrom-Dormand-Prince (RK-N-DP) order integration. The ion source model with Gaussian distribution of initial positions and transverse velocities is used. In RF-only operation mode, a resolution power of about R(0.1) = 600 without peak tails is achieved with a separation time of about 50 RF cycles. Relatively high resolution power of about 2000-3000 is observed in DC+RF separation mode with a low frequency auxiliary RF signal. The boundaries of stability diagram for additional RF voltage with high frequency are strongly diffused until the separation time is increased up to n = 300 RF cycles. The strong influence of phase shifts between main drive RF voltage and small auxiliary RF voltage on transmission is also examined. In DC + RF mode, the period of transmission varies with phase shift of pi or one period of the main drive RF voltage; and in RF-only mode this period is pi/2.
Related Concept Videos
Mass Analyzers: Common Types
Atomic Nuclei: Nuclear Relaxation Processes
Mass Analyzers: Overview
Atomic Nuclei: Nuclear Spin State Overview
Nuclear Stability
To hold positively charged protons together in the...
Atomic Nuclei: Magnetic Resonance

