公开(公告)号：US20110168887A1

公开(公告)日：2011-07-14

申请号：US12685953

申请日：2010-01-12

Applicant: Angus BEWICK

Inventor： Angus BEWICK

IPC: H01J37/147 ,  H01J37/26

CPC classification number: H01J37/09 ,  H01J37/244 ,  H01J37/28 ,  H01J2237/0264 ,  H01J2237/028 ,  H01J2237/24415

Abstract: A charged particle filter comprises a magnetic deflector and an outer shield. The magnetic deflector has a bore along an axis thereof passing through the deflector from a specimen end to a detector end of the deflector and through which charged particles pass when in use. The deflector is formed from one or more magnets positioned around the bore in a Halbach configuration thereby generating a relatively high magnetic field strength within the bore and a relatively low magnetic field strength outside of the deflector. The deflector has a geometry defining an outer surface and an inner surface, wherein each of the outer and inner surfaces of the deflector taper towards the axis as a respective function of distance in the specimen direction along the axis. The outer shield is formed from a soft magnetic material surrounding the magnet deflector on an outer surface side of the deflector and having a projecting portion which extends in the specimen direction with respect to the magnetic deflector from the specimen end of the deflector.

Abstract translation: 带电粒子滤波器包括磁偏转器和外屏蔽件。 磁偏转器具有沿其轴线的孔，其穿过偏转器从试样端到偏转器的检测器端，并且当使用时带电粒子通过该孔。 偏转器由一个或多个以Halbach构型围绕孔定位的磁体形成，从而在孔内产生相当高的磁场强度，并在偏转器外部产生相对低的磁场强度。 偏转器具有限定外表面和内表面的几何形状，其中偏转器的外表面和内表面中的每一个作为沿着轴线的样本方向上的距离的相应函数朝向轴逐渐变细。 外护罩由围绕偏转器外侧表面侧的磁性偏转器的软磁性材料形成，并且具有突出部，该突出部从导流板的试样端部相对于导磁板在试样方向上延伸。