Multi-pole cold trap system with efficient refrigeration function

The invention discloses a multi-pole-rod cold trap system capable of achieving efficient refrigeration. The system comprises an octopole-rod ion trap, an ion focusing lens set and a twenty-two-pole-rod ion trap. According to the invention, a radio frequency electric field which changes drastically in a cylinder space of the octopole rod is adopted to drive hotter ions to move in the field, so thatthe ions rapidly collide with buffer gas, and the design target that the temperature of the octopole rod is reduced from 300K to 40K during single flight of the ions is achieved; pre-cooled ions aregathered and restrained through a radio frequency potential well formed by a twenty-two pole rod, and the pre-cooled ions and buffer gas are fully collided till the temperature is cooled to reach about 4.2 K of the set temperature under the restraint of an axial gradient electrode. The cooling efficiency of ions is improved through two-stage refrigeration, the cooling time of the ions is shortened, and the purpose of effic