Ion detector

Patent metadata

Field	Value
Publication number	US-10832896-B2
Application number	US-201916281469-A
Country	US
Kind code	B2
Filing date	Feb 21, 2019
Priority date	Feb 22, 2018
Publication date	Nov 10, 2020
Grant date	Nov 10, 2020

Abstract

The present embodiment relates to an ion detector provided with a structure for suppressing degradation over time in an electron multiplication mechanism in the ion detector. The ion detector includes a dynode unit, serving as an electron multiplication mechanism, which multiplies secondary electrons which are emitted in response to incidence of ions, and a semiconductor detector having an electron multiplication function. Further, a focus electrode having an opening that allows passage of secondary electrons is disposed on a trajectory of secondary electrons which are directed from the dynode unit toward the semiconductor detector, and the focus electrode functions to guide secondary electrons from the dynode unit onto an electron incidence surface of the semiconductor detector.

First claim

What is claimed is:

1. An ion detector comprising:
an ion incidence portion;
a conversion dynode disposed at a position where ions taken up through the ion incidence portion reach, the conversion dynode emitting secondary electrons in response to incidence of the ions;
a dynode unit for cascade-multiplying secondary electrons emitted from the conversion dynode, the dynode unit being constituted by multiple stages of dynodes disposed along a predetermined electron multiplication direction;
a first electron detection unit that includes a semiconductor detector having an electron multiplication function, the first electron detection unit being configured such that the semiconductor detector is disposed at a position where secondary electrons emitted from a final-stage dynode included in the dynode unit reach;
a focus electrode disposed on a trajectory of secondary electrons which are directed from the final-stage dynode toward the first electron detection unit, the focus electrode having an opening for allowing passage of secondary electrons emitted from the final-stage dynode;
a first support substrate on which an electrode unit including at least the conversion dynode, the dynode unit, and the focus electrode is mounted while being physically separated from at least the focus electrode; and
a second support substrate disposed between the focus electrode and the first support substrate, the second support substrate having a surface on which at least the first electron detection unit is directly mounted.

2. The ion detector according to claim 1 ,
wherein the final-stage dynode included in the dynode unit has a first wall portion deflecting a traveling direction of secondary electrons, the first wall portion being in direct contact with the final-stage dynode and extending along a direction intersecting the electron multiplication direction, and
the focus electrode and the semiconductor detector are disposed along the traveling direction of secondary electrons.

3. The ion detector according to claim 2 ,
wherein the first wall portion of the final-stage dynode included in the dynode unit extends along a direction orthogonal to the electron multiplication direction,
the focus electrode is disposed so that a first normal line that passes through a center of the opening is orthogonal to the electron multiplication direction, and
the semiconductor detector is disposed so that second normal line that passes through a center of an electron incidence surface of the semiconductor detector is orthogonal to the electron multiplication direction.

4. The ion detector according to claim 3 ,
wherein the focus electrode and the semiconductor detector are disposed so that the first normal line and the second normal line are parallel to each other and separated from each other by a predetermined distance.

5. The ion detector according to claim 1 ,
wherein the focus electrode is disposed so that a third normal line that passes through a center of the opening is parallel to the electron multiplication direction, and
the semiconductor detector is disposed so that a fourth normal line that passes through a center of an electron incidence surface of the semiconductor detector is parallel to the electron multiplication direction.

6. The ion detector according to claim 5 ,
wherein the focus electrode and the semiconductor detector are disposed so that the third normal line and the fourth normal line are parallel to each other and separated from each other by a predetermined distance.

7. The ion detector according to claim 1 ,
wherein the focus electrode has a second wall portion being in direct contact with the focus electrode and extending along a direction intersecting the electron multiplication direction.

8. The ion detector according to claim 1 ,
wherein the second support substrate is electrically insulated from the first support substrate.

9. The ion detector according to claim 8 ,
wherein a relative position between the first and second support substrates is fixed in a state where the first and second support substrates are capable of being physically separated from each other.

10. The ion detector according to claim 1 further comprising a second electron detection unit, disposed adjacent to any intermediate dynode other than the final-stage dynode among dynodes constituting the dynode unit, which has an electrode for capturing at least some of secondary electrons having reached the intermediate dynode.

11. The ion detector according to claim 1 , further comprising a second electron detection unit that has an electrode including any intermediate dynode other than the final-stage dynode among dynodes constituting the dynode unit.

12. The ion detector according to claim 1 ,
wherein the ion incidence portion has a first opening and a second opening through which the ions respectively pass, the first opening being disposed on a first plane, the ions passing through the first opening, the second opening being disposed on a second plane intersecting the first plane.

13. The ion detector according to claim 1 ,
wherein the surface of the second support substrate is a continuous surface on which both the first electron detection unit and an electrode pad are directly mounted.

Assignees

• Hamamatsu Photonics Kk

Inventors

• Kobayashi Hiroshi
• Endo Takeshi
• Moriya Hiroki
• Mochizuki Toshinari

Classifications

• H01J49/025

  Detectors specially adapted to particle spectrometers (data acquisition H01J49/0036; detectors per se G01T, e.g. G01T1/28, G01T1/29) · CPC title

• H01J43/18 Primary

  Electrode arrangements using essentially more than one dynode · CPC title

• H01J43/06

  Electrode arrangements · CPC title

• H01J43/26 Primary

  Box dynodes · CPC title