Mass spectrum equipment of accelerator, and method for measuring mass spectrum 14C of accelerator

Abstract

The invention provides an accelerator mass spectrometry device based on a low energy dispersion RFQ accelerator and a corresponding accelerator mass spectrometry 14C measurement method, belonging to the technical field of accelerator mass spectrometry. The accelerator mass spectrometry device includes: an ion source, a buncher, an RFQ accelerator, an electron stripper, a high-energy analysis system, and a detector, the above components are connected in sequence, and the RFQ accelerator accelerates 14C, 12C, and 13C ions to a certain energy to carry out electron analysis. Stripping to remove molecular ion interference. The invention uses a low-energy-dispersion RFQ acceleration structure as the ion acceleration device in the 14C measurement accelerator mass spectrometry (AMS) system, and realizes the alternate acceleration of 14C, 12C, and 13C ions by alternately changing the RF power fed into the RFQ accelerator. There is no need for steel cylinders, insulating gas, alternate injection systems, etc. in traditional AMS, and the overall structure is simplified.

Description

technical field [0001] The invention belongs to the technical field of accelerator mass spectrometry, in particular to an accelerator mass spectrometry device and an accelerator mass spectrometer based on a low energy dispersion RFQ accelerator 14 C measurement method. Background technique [0002] Accelerator mass spectrometry (AMS), as an analytical technique with ultra-high sensitivity, has been widely used in the fields of earth science, archaeology, life science, environmental science, astrophysics and material science. The main measurements of the AMS device 14 The ratio of C and other radionuclides to their stable isotopes can be used for dating or tracing research. It uses an accelerator to accelerate the nuclide ions to be tested to a higher energy, which can effectively suppress molecular ions and isobaric interference. achieve ultra-high sensitivity. AMS performance is mainly measurement accuracy, sensitivity and measurement efficiency. [0003] A general AMS ...

AI Technical Summary

Problems solved by technology

Both types of accelerators use the high-voltage electric field generated between the high-voltage electrode and the ground potential to accelerate ions. The high-voltage electrode and the accelerating tube need to be placed in a steel cylinder filled with high-voltage SF 6 Gas for insulation, apparently using SF 6 Gas is not good for environmental protection

In order to ensure the insulation effect, more complex devices such as gas circulation drying treatment are required

In order to ensure the measurement accuracy, different isotope ions need to be accelerated through the accelerator, but the beam loading capacity of this type of accelerator is low, and a relatively complex alternate injection system is required, so that the stable isotope with high flow intensity can only be injected into the accelerator in a short time

Some people also use the method of simultaneous implantation, but the implantation system is more complicated. It is necessary to separate the different isotope ions first, attenuate the stable isotope ion beam with a higher current intensity, and then inject the different isotope ions into the accelerator.

The measurement background of this simultaneous injection method is relatively high, and the corresponding high-energy analysis system is relatively complicated.

[0004] Recently, a Single StageAMS (SSAMS) device has appeared. This device uses a 300kV single-stage electrostatic acceleration tube and does not require a steel cylinder. However, some devices are inevitably at high potentials, which is inconvenient to operate and has certain limitations. , and the measurement sensitivity is affected to some extent due to the low energy

[0005] There is also a small cyclotron that is also used in AMS. The AMS based on this kind of accelerator has low measurement accuracy and measurement efficiency due to the restriction of transmission efficiency.

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