Patent ID: 7309860

Claim:
An electron capture dissociation device comprising: a linear ion trap having linear multipole electrodes applied with a radio frequency electric field and wall electrodes that are arranged on both ends in an axis direction of the linear multipole electrodes, said wall electrodes being provided with holes on the axis of the linear multipole electrodes and applied with a direct-current voltage to generate a wall electric field; a cylindrical magnetic field-generating unit that generates a magnetic field containing the same axis as the axis of the linear multipole electrodes and surrounds the linear ion trap; and an electron source arranged opposite to the linear multipole electrodes with one of the wall electrodes sandwiched in-between to pass electrons generated from the electron source towards the linear multipole electrodes, wherein an electron generation site of the electron source is placed inside the magnetic field generated by the magnetic field-generating unit, wherein ions are introduced and ejected from the wall electrode not on the side of the electron source.