公开(公告)号：US06670625B1

公开(公告)日：2003-12-30

申请号：US10064174

申请日：2002-06-18

Applicant: Roy E. Rand ,  Khem Garewal

Inventor： Roy E. Rand ,  Khem Garewal

IPC: G01N2300

CPC classification number: G21K1/087

Abstract: A method and apparatus are disclosed for reducing variation in a spot size of an electron beam at a target due to multipole aberrations in an electron beam tomography (EBT) scanner. A magnitude of a DC voltage applied to a positive ion electrode (PIE) within the EBT scanner is adjusted and an orientation of a non-circular aperture of the PIE is aligned with respect to the electron beam. A profile of the spot size is monitored while adjusting the magnitude of the DC voltage and while aligning the orientation of the non-circular aperture of the PIE until the variation in the spot size is sufficiently reduced.

Abstract translation: 公开了一种用于减少由于电子束层析成像（EBT）扫描仪中的多极像差导致的目标处的电子束的斑点尺寸变化的方法和装置。 调整施加到EBT扫描仪内的正离子电极（PIE）的DC电压的大小，并且PIE的非圆形孔径的取向相对于电子束对准。 在调整直流电压的大小并同时对齐PIE的非圆形孔径的方向直到光斑尺寸的变化充分降低时，监测光斑尺寸的轮廓。

公开(公告)号：US5491734A

公开(公告)日：1996-02-13

申请号：US167419

申请日：1993-12-14

Applicant: Douglas P. Boyd ,  Roy E. Rand

Inventor： Douglas P. Boyd ,  Roy E. Rand

IPC: H05G2/00 ,  A61B6/03 ,  H01J35/24 ,  H05G1/26 ,  H05G1/60

CPC classification number: H05G1/26 ,  A61B6/032 ,  A61B6/4028 ,  H01J35/24

Abstract: A scanning electron beam CT system generates an electron beam along a beam source axis offset from the scanner axis, or axis of symmetry, thereby permitting the X-ray subject to pass completely through the stationary gantry. The electron beam is produced with the first drift tube region of an evacuated housing chamber, and is directed downstream toward a second region that includes a gantry. A scan target and a tuning target, each concentric with and defining a plane normal to the system axis of symmetry, are located in the gantry. A beam optics system, through which the electron beam passes, is located within the housing intermediate the electron gun and gantry. A control system focusses and scans the electron beam upon the scan target, maintaining a beam spot of desired quality. Upon impingement by the scanning beam spot, the scan target emits a fan beam of X-rays. A detector array, concentric with and defining a plane normal to the system axis of symmetry, is located opposite the scan target within the gantry and provides output signals that are computer processed to reconstruct a CT image of a subject placed within the gantry. The scanner axis is preferably above the beam source axis, and preferably the drift tube is straight, defining a drift tube axis that is inclined relative to the scanner axis, or is parallel to the scanner axis but not co-axial therewith. Alternatively, the drift tube may be kinked.

Abstract translation: 扫描电子束CT系统沿着从扫描器轴线或对称轴偏移的光束源轴产生电子束，从而允许X射线物体完全通过固定台架。 电子束由抽真空的容纳室的第一漂移管区域产生，并且被引向下游朝向包括台架的第二区域。 扫描目标和调谐目标，每个同心于并定义与系统对称轴垂直的平面，位于台架中。 电子束通过的光束系统位于电子枪和龙门架内部的壳体内。 控制系统将电子束聚焦并扫描到扫描目标上，保持所需质量的光点。 在被扫描光束点撞击时，扫描目标发射X射线的风扇束。 检测器阵列同心于并限定垂直于系统对称轴的平面，与机架内的扫描目标相对，并提供计算机处理的输出信号，以重建放置在机架内的被摄体的CT图像。 扫描器轴优选地在波束源轴线上方，并且优选地，漂移管是直的，限定相对于扫描器轴线倾斜或者平行于扫描器轴线但不与其同轴的漂移管轴线。 或者，漂移管可以扭结。

公开(公告)号：US5386445A

公开(公告)日：1995-01-31

申请号：US166545

申请日：1993-12-14

Applicant: Roy E. Rand

Inventor： Roy E. Rand

IPC: G01N23/04 ,  A61B6/03 ,  G21K5/02 ,  G21K5/08 ,  H01J35/14 ,  H01J37/12 ,  H01J37/21 ,  H01J35/06

CPC classification number: H01J35/14 ,  A61B6/032 ,  A61B6/4028

Abstract: In a scanning electron beam CT system, the electron beam is focused by controlling the distribution of beam-generated ions electrostatically. The upstream (self-expanding, de-focusing) beam region and downstream (converging, self-focusing) beam region are distinguished by the absence or presence of beam-generated positive ions. The relative lengths of these two beam regions are electrostatically controlled such that beam de-focusing in the upstream region compensates for beam self-focusing in the downstream region. In this fashion, essentially zero external focusing strength is required, and the magnetic focus coil used in the prior art is eliminated. Located downstream from the electron gun, a positive ion electrode ("PIE") determines the position of the boundary between the two regions, and thus the relative length of each region. The PIE is a disk-like electrode, mounted coaxially to the beam optic axis within the drift tube, and coupled to a large positive potential. Varying the PIE potential varies the inter-region boundary position, and thus the relative magnitudes of the beam de-focusing and self-focusing effects. A PIE focus potential is determined by varying the potential while examining the output of electron beam monitors with an oscilloscope. Further, by dynamically varying the PIE potential, the present invention adjusts electron beam focusing, even during a scan. Positive ions are removed from the upstream region by a periodic ion clearing electrode ("PICE") whose high rate of change of axial potential creates alternating axial fields that rapidly sweep away ions.

Abstract translation: 在扫描电子束CT系统中，通过静电控制光束产生的离子的分布来聚焦电子束。 通过不存在或存在光束产生的正离子来区分上游（自扩张，去聚焦）光束区域和下游（会聚，自聚焦）光束区域。 这两个光束区域的相对长度被静电控制，使得上游区域中的光束去聚焦补偿下游区域中的光束自聚焦。 以这种方式，基本上需要外部聚焦强度为零，并且消除了现有技术中使用的磁聚焦线圈。 位于电子枪的下游，正离子电极（“PIE”）确定两个区域之间的边界的位置，从而确定每个区域的相对长度。 PIE是一种盘状电极，与漂移管内的光束轴线同轴安装，并耦合到大的正电位。 改变PIE电位会改变区域间边界位置，从而改变光束去聚焦和自聚焦效应的相对幅度。 通过使用示波器检查电子束监视器的输出，通过改变电位来确定PIE聚焦电位。 此外，通过动态地改变PIE电位，本发明即使在扫描期间也调整电子束聚焦。 通过周期性离子清除电极（“PICE”）从上游区域去除正离子，其高轴向电位变化率产生快速扫除离子的交替轴向场。

公开(公告)号：US5224137A

公开(公告)日：1993-06-29

申请号：US705575

申请日：1991-05-23

Applicant: Susan E. Plomgren ,  John L. Couch ,  Mark C. Nicely ,  Roy E. Rand

Inventor： Susan E. Plomgren ,  John L. Couch ,  Mark C. Nicely ,  Roy E. Rand

IPC: A61B6/03 ,  H01J35/14 ,  H01J35/30

CPC classification number: A61B6/032 ,  A61B6/4028 ,  H01J35/14 ,  H01J35/30

Abstract: A scanning electron beam computed tomography scanner is disclosed herein and includes means defining a vacuum chamber, means for producing an electron beam at one location in the chamber and for directing it to a second location therein, a target located at a third position therein of the type which produces X-rays as a result of the impingement thereon by the electron beam, means for focusing the beam onto the target in the form of a beam spot and for scanning the beam spot across the target along a particular scan path in order to produce X-rays, and means for monitoring the profile, position, and orientation of the beam spot at a plurality of locations along the scan path. The specific scanner disclosed also includes an arrangement for determining from the signals produced by the monitoring devices if the beam spot conforms to as desired profile, position, and orientation and automatically adjusting the electron beam such that its profile, position, and orientation conform to desired values.

Abstract translation: 本文公开了扫描电子束计算机断层摄影扫描仪，并且包括限定真空室的装置，用于在腔室中的一个位置处产生电子束并将其引导到其中的第二位置的装置，位于其中的第三位置的靶 作为由于电子束撞击其而产生X射线的类型，用于以束斑的形式将光束聚焦到目标上的装置，并且用于沿着特定扫描路径扫描靶点以跨过目标，以便 产生X射线，以及用于监测沿着扫描路径的多个位置处的束斑的轮廓，位置和取向的装置。 所公开的具体扫描器还包括用于根据监视装置产生的信号来确定束斑是否符合期望的轮廓，位置和取向以及自动调节电子束以使其轮廓，位置和取向符合期望的装置 价值观。

公开(公告)号：US4993055A

公开(公告)日：1991-02-12

申请号：US275780

申请日：1988-11-23

Applicant: Roy E. Rand ,  Douglas P. Boyd ,  Kristian R. Peschmann

Inventor： Roy E. Rand ,  Douglas P. Boyd ,  Kristian R. Peschmann

IPC: H01J35/10 ,  H01J35/14 ,  H01J35/30

CPC classification number: H01J35/305 ,  H01J35/106 ,  H01J35/14 ,  H01J2235/162

Abstract: X-ray tube includes a rotatable envelope in which is mounted an electron gun at one end and a target anode at the other end. A fixed means for deflecting the electron beam from the electron gun is provided to deflect the electron beam on a fixed path as the envelope of the x-ray tube rotates about an axis. The electron beam being confined to a fixed path results in the electron beam striking various positions of the target anode to provide for improved heat dissipation. The electron beam is deflected along the fixed path using magnetic deflection means including magnetic deflection coils positioned external of the envelope to provide a deflection field transverse to the electron beam. The target anode is cooled by directing a cooling fluid on an external side of the target anode.

Abstract translation: X射线管包括可旋转的外壳，其中在一端安装电子枪，另一端安装目标阳极。 提供用于偏转来自电子枪的电子束的固定装置，用于使X射线管的外壳围绕轴旋转，使电子束在固定路径上偏转。 限制在固定路径上的电子束导致电子束撞击目标阳极的各个位置以提供改进的散热。 使用包括位于外壳外部的磁偏转线圈的磁偏转装置使电子束沿固定路径偏转，以提供横向于电子束的偏转场。 通过在目标阳极的外侧引导冷却流体来冷却目标阳极。

公开(公告)号：US4631741A

公开(公告)日：1986-12-23

申请号：US597133

申请日：1984-04-05

Applicant: Roy E. Rand ,  John L. Couch

Inventor： Roy E. Rand ,  John L. Couch

IPC: H01J35/00 ,  H01J35/14 ,  H05G1/26 ,  H05G1/52 ,  H01J35/30

CPC classification number: H01J35/14 ,  H01J35/00 ,  H05G1/26

Abstract: A scanning beam computed tomography scanner is disclosed herein and includes means defining a vacuum chamber, means for producing an electron beam at one location in the chamber and for directing it to a second location therein, a target of the type which produces X-rays as a result of the impingement thereon by the electron beam, and means for focusing the beam onto the target in the form of a beam spot and for scanning the beam spot across the target along a particular scan path in order to produce X-rays. The specific scanner disclosed also includes an arrangement for monitoring the profile, position and orientation of the beam spot at a plurality of different points along the scan path.

Abstract translation: 本文公开了扫描光束计算机断层摄影扫描器，并且包括限定真空室的装置，用于在室中的一个位置处产生电子束并将其引导到其中的第二位置的装置，产生X射线的类型的靶 由电子束撞击其的结果，以及用于以束斑形式将光束聚焦到目标上并用于沿特定扫描路径扫描靶点以产生X射线的装置。 所公开的具体扫描仪还包括用于监视沿着扫描路径的多个不同点处的光斑的轮廓，位置和取向的装置。

公开(公告)号：US4521900A

公开(公告)日：1985-06-04

申请号：US434252

申请日：1982-10-14

Applicant: Roy E. Rand

Inventor： Roy E. Rand

IPC: A61B6/03 ,  H01J35/00 ,  H01J35/04 ,  H05G1/52 ,  H01J35/24

CPC classification number: H01J35/00

Abstract: An electron beam production and control assembly especially suitable for use in producing X-rays in a computed tomography (CT) X-ray scanning system is disclosed herein along with its method of operation. This assembly produces its electron beam within a vacuum-sealed housing chamber which is evacuated of internal gases, except inevitably for small amounts of residual gas. The electron beam is produced by suitable means within the chamber and directed along a path therethrough from the chamber's rearwardmost end to its forwardmost end whereby to impinge on a suitable target for producing the necessary X-rays. Since there is residual gas within the chamber, the electrons of the beam will interact with it and thereby produce positive ions which have the effect of neutralizing the space charge of the electron beam. However, there are a number of different arrangements disclosed herein which form part of the overall assembly for acting on these ions and reducing the neutralizing effect they would otherwise have on the beam.

Abstract translation: 本文中公开了一种特别适合于在计算机断层摄影（CT）X射线扫描系统中生产X射线的电子束产生和控制组件及其操作方法。 该组件在真空密封的容纳室内产生其电子束，该容器室除了少量的残余气体之外不可避免地被内部气体抽真空。 电子束通过合适的装置在室内产生，并且沿着从腔室的最后端到其最前端的通路引导，从而撞击在合适的靶上以产生必需的X射线。 由于在室内存在残留气体，所以光束的电子将与其相互作用，从而产生具有中和电子束空间电荷的正离子。 然而，这里公开了许多不同的布置，其构成了用于作用在这些离子上的整体组件的一部分，并且减小了它们对梁的中和作用。

公开(公告)号：US5193105A

公开(公告)日：1993-03-09

申请号：US809924

申请日：1991-12-18

Applicant: Roy E. Rand ,  Eugene Y. Tsiang

Inventor： Roy E. Rand ,  Eugene Y. Tsiang

IPC: H01J35/04

CPC classification number: H01J35/04

Abstract: An electron beam scanning system employing a relatively short housing chamber wherein an electron beam is produced includes an ion controlling electrode assembly. Located in the housing between the electron gun and system beam optics, the assembly includes a generally cone-shaped rotating field ion controlling electrode (or "RICE") unit comprising cylindrically symmetrical element pairs disposed on opposite sides of the housing Z-axis. Preferably equal and opposite potential sources coupled to elements comprising an element pair create a transverse electric field therebetween. The vector sum of the fields produced by all element pairs is the transverse field created by the RICE unit. The potentials are varied, rotating the overall RICE field to controllably remove most but not all positive ions. The remaining ions improve the electron beam space-charge density, resulting in a sharply focused scanning electron beam. Preferably a disk-like positive ion electrode (or "PIE") unit coupled to a large positive potential is disposed downstream from the RICE unit to block upstream migration of positive ions. Where discontinuities are present in the housing, a periodic axial field ion controlling electrode (or "PICE") unit is disposed at the upstream end of the overall assembly. The PICE comprises spaced-apart disks alternately coupled to large and small potentials to create alternating axial fields within a short axial distance, to rapidly sweep away ions. Regions within the overall assembly not otherwise acted upon by fields are covered with one or more conventional ICE units to sweep away positive ions.

Abstract translation: 采用其中产生电子束的相对较短的壳体室的电子束扫描系统包括离子控制电极组件。 位于电子枪和系统光束光学器件之间的壳体中，组件包括大致锥形的旋转场离子控制电极（或“RICE”）单元，其包括设置在壳体Z轴的相对侧上的圆柱对称元件对。 优选地，耦合到包括元件对的元件的相等和相反的电位源在它们之间产生横向电场。 由所有元素对产生的场的矢量和是由RICE单元创建的横向场。 电位变化，旋转整个RICE领域可控制地去除大部分但不是全部的正离子。 剩余的离子可以改善电子束的空间电荷密度，从而产生清晰的扫描电子束。 优选地，耦合到大正电位的盘状正离子电极（或“PIE”）单元设置在RICE单元的下游以阻止正离子的上游迁移。 在壳体中存在不连续性的情况下，周期性轴向场离子控制电极（或“PICE”）单元设置在整个组件的上游端。 PICE包括交替地耦合到大的和小的电位的间隔开的盘，以在短的轴向距离内产生交替的轴向场，以快速地扫除离子。 整个组件内的区域不是由场所影响的区域被一个或多个常规的ICE单元覆盖以扫除正离子。

公开(公告)号：US4625150A

公开(公告)日：1986-11-25

申请号：US600464

申请日：1984-04-16

Applicant: Roy E. Rand

Inventor： Roy E. Rand

IPC: H01J3/40 ,  H01J35/14 ,  H01J29/84

CPC classification number: H01J35/14 ,  H01J3/40

Abstract: An improved ion clearing electrode assembly for use in an electron beam production and control assembly which is especially suitable for use in a scanning electron beam computed tomography X-ray scanning system. The assembly uses a vacuum sealed housing chamber which is evacuated of internal gases and in which the electron beam is generated and propagated. Normally residual gas within the chamber interacts with the electrons of the beam to produce positive ions which have the affect of neutralizing the space charge of the electron beam and thereby causing focusing difficulties and destabilization of the beam. The ion collecting electrodes herein are an improvement of those disclosed in the co-pending Rand U.S. patent application Ser. No. 434,252, now U.S. Pat. No. 4,521,900. The electrodes are designed to extract the ions and reduce their neutralizing effect while maintaining a precisely uniform electric field and therefore beam optical aberrations are minimized. In addition, the electrode provides flexibility in the variation of parameters which effect ion extraction and the neutralization fraction.

Abstract translation: 一种用于电子束生产和控制组件的改进的离子清除电极组件，其特别适用于扫描电子束计算机断层摄影X射线扫描系统。 组件使用真空密封的容纳室，其被内部气体排空，并且其中电子束被产生和传播。 通常，室内的残余气体与光束的电子相互作用以产生具有中和电子束的空间电荷的影响的正离子，从而引起聚焦困难和光束的不稳定性。 本文中的离子收集电极是共同未决的兰德美国专利申请系列公开的那些的改进。 现在的美国专利第434,252号。 第4,521,900。 电极被设计成提取离子并降低它们的中和效应，同时保持精确均匀的电场，并且因此光束像差最小化。 此外，电极提供影响离子提取和中和分数的参数变化的灵活性。

公开(公告)号：US07872241B2

公开(公告)日：2011-01-18

申请号：US12274067

申请日：2008-11-19

Applicant: Roy E. Rand

Inventor： Roy E. Rand

IPC: G21K1/08 ,  H01J3/14 ,  H01J3/26 ,  H01J49/42

CPC classification number: H01J35/30 ,  H01J35/08 ,  H01J35/14 ,  H01J37/026 ,  H01J37/3007 ,  H01J2235/086 ,  H01J2235/20

Abstract: An electron beam production and control assembly includes a vacuum chamber, a beam source, and a target. The target has an active section and an inactive section. The active section is adapted to generate x-rays when the beam impinges on the x-ray producing section. The electron beam production and control assembly also includes a focusing unit positioned along the chamber at a location intermediate the rearward end and the forward end. The focusing unit directs the beam towards the target in a converging manner to impinge on the target. The focusing unit sweeps the beam along a scanning path over the active section of the target. The focusing unit moves the beam to a retrace path on the inactive section of the target between sweeps of the scanning path to maintain ion accumulation in the beam between sweeps over the active section.

Abstract translation: 电子束产生和控制组件包括真空室，束源和靶。 目标具有活动部分和非活动部分。 当激光束照射在x射线产生部分上时，活动部分适于产生X射线。 电子束产生和控制组件还包括聚焦单元，该聚焦单元沿着腔室位于后端和前端的中间位置。 聚焦单元以会聚的方式将光束引向目标以撞击目标。 聚焦单元沿着目标的有效部分上的扫描路径扫描光束。 聚焦单元将光束移动到扫描路径扫描之间的目标的非活动部分上的回扫路径，以在扫描之间的过程中保持离子积聚在有效部分之间。