| 摘要 |
<p>An ion-storage device has an electrode structure (Figure 3a) for subjecting ions in a defined region R along a path P to an electrostatic retarding field. The electrostatic retarding field is in the form of an electrostatic quadrupole field. Ions enter the defined region R at a position P1 on the path and they exit the defined region at a position P2, having travelled a distance xT. Ions are subjected to the electrostatic retarding field during an initial part only of a preset time interval and the velocity of each ion during that part of the preset time interval is related linearly to its separation x from the exit position P2 by the expression, <MATH> where m is the mass of the ion, q is its charge and k is a constant. Ions having the same mass-to-charge ratio (m/q) all exit the field region at the same time during the remaining part of the preset time interval. <IMAGE></p> |
