Ion Trap RF Tuning for Broad Mass-Range Detection
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Solution Overview
Problem
Existing ion detection apparatuses using electric ion resonance cells face limitations in mass resolution and sensitivity, particularly when detecting ions over a large bandwidth of mass-to-charge ratios.
Innovation Solution
The apparatus operates with an ion trap that generates an electric storage field with freely adjustable amplitude and frequency of the RF storage signal, allowing for increased mass range detection and non-destructive ion detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a constant frequency RF storage signal is used, then low-loss generation and simplified crosstalk compensation are achieved, but the mass range and detection bandwidth are limited
Solution Approach 1:
The patent applies dynamics by transitioning from a static constant frequency RF storage signal to a dynamic variable frequency RF storage signal. The storage signal generator is designed to adjust the frequency of the RF storage signal dynamically, allowing the ion trap to detect ions across a broader mass range. This dynamic adjustment enables the system to adapt to different mass-to-charge ratio requirements while maintaining stable ion storage and detection capabilities.
Solution Approach 2:
The patent implements parameter changes by modifying the frequency parameter of the RF storage signal. Instead of using a fixed frequency, the system varies the frequency parameter to optimize detection across different mass ranges. This parameter adjustment allows the ion trap to maintain stable operation while expanding its detection bandwidth and mass range capability.
2Adaptability or versatility
If the RF storage signal frequency is increased to expand mass range, then detection bandwidth improves, but power loss increases
Solution Approach 1:
The system uses dynamic frequency adjustment to optimize the balance between detection bandwidth and power loss. By dynamically selecting appropriate frequencies based on the specific detection requirements, the system can expand mass range when needed while operating at lower frequencies to minimize power loss during routine operations.
Solution Approach 2:
The patent employs parameter changes by adjusting the RF storage signal frequency to match the detection needs. When detecting ions with larger mass-to-charge ratios, the frequency is increased to expand the mass range. When power efficiency is prioritized, the frequency is reduced, thereby optimizing the trade-off between detection bandwidth and power consumption.
3Measurement precision
If non-destructive detection is implemented, then ion signal acquisition is improved, but crosstalk interference increases
Solution Approach 1:
The patent applies the extraction principle by separating the detection function from the storage function. The system extracts the ion signal detection capability while maintaining ion storage, allowing non-destructive detection. By using a detection electrode configured to detect ion signals without requiring ion removal from the trap, the system achieves improved signal acquisition while managing crosstalk interference through frequency adjustment.
Solution Approach 2:
The system uses parameter changes by adjusting the RF storage signal frequency to optimize the balance between detection sensitivity and crosstalk suppression. By selecting appropriate frequency parameters, the system enhances ion signal detection sensitivity while minimizing the impact of crosstalk currents generated during non-destructive detection.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables the detection of ions across a broader range of mass-to-charge ratios, improving mass resolution and sensitivity while minimizing interference currents.
Implementation Method 1
an RF storage signal in the form of a radio-frequency AC voltage is applied to the ring electrode. By virtue of the RF storage signal, an electric field (quadrupole field) is generated in the ion trap, said electric field also being referred to as an electric storage field, since ions or charged particles in such a field can be stored stably in the ion trap
Implementation Method 2
the ions are excited by an excitation signal to effect oscillations, the frequency of which is dependent on the ion mass or dependent on the mass-to-charge ratio of the excited ions
Implementation Method 3
the ions are detected by the measurement of induced charges on the cap electrode or cap electrodes of the ion trap
Implementation Method 4
The crosstalk or interference current arise at the second electrode, at which the ion signal is measured, on account of a capacitive coupling to the first electrode that is caused by the radio-frequency electric storage field
Data Source
Figure 1~2c
Figure 3~5
Figure 6~8c
AI summary
The invention relates to an apparatus (1) for detecting ions (4a, 4b), comprising: an ion trap (2) having a first electrode, preferably a ring electrode (3) and also having at least one second electrode, preferably a cap electrode (7a, 7b), a storage signal generator (5) for generating an RF storage signal (URF), which can be coupled into the first electrode (3) in order to generate an electric storage field (E) in the ion trap (2), and also an excitation device (6a, 6b) for generating an excitation signal (Ustim1, Ustim2) for exciting ions (4a, 4b) stored in the ion trap (2). The storage signal generator (5) is designed to set an amplitude (ARF) and/or a frequency (fRF) of the RF storage signal (URF). The invention also relates to an associated method for mass-selective detection of ions (4a, 4b). Furthermore, a suitable ionization method with constant or targeted ionization energies is presented.