Simulation And Test Of A Multi-Reflection Time-of-Flight Mass Spectrometer

Arguably,the most basic property of a nucleus is its mass,closely related to its binding energy,which reflects the sum effect of the complicated interplay of the strong,electromagnetic and weak interactions.Precise measurement of nuclei's masses presents a broad range of interests in different domains,such as understanding of nuclear composition,testing nuclear model in nuclear structure,explaining the stellar explosion and nucleosynthesis in astrophysics.Among all the devices for mass measurement,the Multi-Reflection Time-of-Flight Mass Spectrometer?MR-ToF-MS?is a revolutionary technique which allows achieving the precise mass measurement of radioactive isotopes with short-life time?<10ms?,meets the challenges of mass spectrometry at current and future accelerator facilities for the research with exotic nuclei.In this thesis,as what we study,the PILGRIM?PiègeàIons Linéaire du GANIL pour la Résolution des Isobares et la measure de Masse?is a kind of MR-ToF-MS,which is dedicated to study the very heavy and super heavy nuclei in GANIL.Now,it is under development and primary test in LPC Caen.PILGRIM will be installed in the S3-LEB?Super Separator Spectrometer-Low Energy Branch?project to fulfill the beam purification and precise mass measurement in 2018.In order to reach to higher resolving power,PILGRIM needs a good beam injection which the Radio-frequency Quadrupole?RFQ?Cooler and Buncher will provide.In this report,the PILGRIM setup is simulated by SIMION to get the optimization result of different electrodes'potential,the value of voltage and time when prodcing bunches with different equipments and the optimization potential setup for different mirrors in the PILGRIM.Then,various experiments of the PILGRIMsetup with stable ions of ⁴⁰Ca⁺⁴⁰K⁺and³⁹K⁺?produced by a thermionic source?are summarized to demonstrate that PILGRIM has an excellent mass resolving powersfor different ion mass and beam intensity in a compact device,the maximum resolving power is 80000 in the experiment and could be enough to saperate the⁴⁰Ca⁺and ⁴⁰K⁺.Meanwhile,the ion beam injection conditions of the S3-LEB project are simulated with the software package"SIMION",which aims for the simulation of collisions between buffer-gas particles and ions?accomplished by LUA Program?in the RFQ Cooler and Buncher.And also discussing the relation between the extraction time and RF phase as well as determining the required cooling time for the ions in the RFQ Cooler and Buncher.The simulation results indicate that the ion cooling in RFQ is a damped oscillation process and the period remains constant which is related to the RF frequency of the RFQ Cooler and Buncher.