RF independence generation of combination with the RF electric field and the axial direction DC electric field multipole in

摘要

An RF-only multipole includes a spiral resistive path formed around each multipole rod body. RF voltages are applied to the rod body and resistive path, and DC voltages are applied to the resistive path and to create a radially confining RF field and an axial DC field that assists in propelling ions through the multipole interior along the longitudinal axis thereof. In one implementation, the resistive path takes the form of a wire of resistive material, such as nichrome and which is laid down in the groove defined between threads formed ON the rod body. The RF-only multipole of the invention avoids the need to use auxiliary rods or similar supplemental structures to generate the axial DC field.