Radiation detector

• US 20040011960A1
• Filed: 04/17/2003
• Published: 01/22/2004
• Est. Priority Date: 04/19/2002
• Status: Active Grant

• Current Assignee: Hitachi High-Tech Science Corporation (Hitachi, Ltd.)
• Original Assignee: SII NanoTechnology Inc. (Hitachi, Ltd.)
• Inventors: Nagata, Atsushi, Ishikawa, Tatsuji, Chinone, Kazuo, Morooka, Toshimitsu, Tanaka, Keiichi
• Granted Patent: US 6,974,952 B2
• Time in Patent Office: Days
• US Class Current: 250/336.1
• CPC Class Codes: G01J 1/06 Restricting the angle of incident light
• CPC Class Codes: G01J 1/42 using electric radiation detectors optical or mechanical part G01J1/04; by comparison with a reference light or electric value G01J1/10

Abstract

There is provided a radiation detector that allows accurate irradiation to a detection area and has a high detection efficiency. A collimator that has an opening for transmitting radiation to irradiate the detection area and a function as a shielding plate for preventing radiation from irradiating a part other than the detection area is installed on the same board that forms an energy/electricity converter (radiation detector). The radiation detector is constructed such that the alignment of the opening of the collimator and the detection area is easy, and the detection area and the opening of the collimator are close so that the detection efficiency is increased.

Claims

1. A radiation detector comprising:

a detection area for detecting incident radiation;

an energy/electricity converter for converting energy of the radiation into an electric signal;

electric signal electrodes for connecting the energy/electricity converter to an external driving circuit formed on a board that forms the energy/electricity converter;

a collimator provided with an opening for transmitting radiation to irradiate the detection area and a function as a shielding plate for preventing radiation from irradiating a part other than the detection area, the collimator being integrally formed on the board that forms the energy/electricity converter; and

a spacer for maintaining a certain distance between the detection area and the collimator, the spacer being integrally formed on the board that forms the energy/electricity converter.

3. The radiation detector according to claim 1, wherein a material of the collimator is a light transmitting material made mainly from glass or sapphire.

5. The radiation detector according to claim 1, wherein the radiation detector is formed by a process in which the energy/electricity converter is formed on a Si substrate, borosilicate glass is used for the spacer, Si is used for the collimator, the energy/electricity converter and the collimator sandwich the spacer therebetween, a temperature and a load are applied thereto, and anodic bonding applying a positive potential to Si material is carried out to bond the energy/electricity converter, the collimator, and the spacer.

7. The radiation detector according to claims 1, wherein the collimator has a bilayer structure constituted by two kinds of materials having different absorption coefficient of radiation to be detected, the material having a lower absorption coefficient is fixed on the board as a supporting member, and the material having a higher absorption coefficient is formed with the opening for transmitting radiation.

9. The radiation detector according to claim 7, wherein the collimator is fixed on the board, and thereafter gets formed with the opening by focused ion beam (FIB) etching.

11. The radiation detector according to claim 1, wherein the energy/electricity converter is a superconducting transition edge sensor that absorbs radiation, converts the radiation into heat, and then extracts energy of the radiation as an electric signal by measuring a change in temperature of thereof, the superconducting transition edge sensor being formed on the board to be a heat sink and comprising a thin film membrane for controlling exhaustion of the heat into the heat sink, a resistor having a superconducting state, a normal conducting state, and an intermediate transition state, for temperature formed on the thin membrane, and electrodes for connection to the external driving circuit.

13. The radiation detector according to claim 11, wherein an absorber is provided on the resistor.

2. A radiation detector comprising:

a detection area for detecting incident radiation;

an energy/electricity converter for converting energy of the radiation;

an electric signal electrodes for connecting the energy/electricity converter to an external driving circuit formed on the energy/electricity converter; and

a collimator provided with an opening for transmitting radiation to irradiate the detection area and a function as a shielding plate for preventing radiation from irradiating apart other than the detection area, the collimator being formed with a cavity for maintaining a certain distance between the detection area and the opening, and the collimator being integrally formed on the board that forms the energy/electricity converter.

4. The radiation detector according to claim 2, wherein a material of the collimator is a light transmitting material made mainly from glass or sapphire.

6. The radiation detector according to claim 2, wherein the radiation detector is formed by a process in which the energy/electricity converter is formed on a Si substrate, borosilicate glass is used for the collimator, the energy/electricity converter and the collimator are laminated, a temperature and a load are applied thereto, and anodic bonding applying a positive potential to the energy/electricity converter is carried out to bond the energy/electricity converter and the collimator.

8. The radiation detector according to claims 2, wherein the collimator has a bilayer structure constituted by two kinds of materials having different absorption coefficient of radiation to be detected, the material having a lower absorption coefficient is fixed on the board as a supporting member, and the material having a higher absorption coefficient is formed with the opening for transmitting radiation.

10. The radiation detector according to claim 8, wherein the collimator is fixed on the board, and thereafter gets formed with the opening by focused ion beam (FIB) etching.

12. The radiation detector according to claim 2, wherein the energy/electricity converter is a superconducting transition edge sensor that absorbs radiation, converts the radiation into heat, and then extracts energy of the radiation as an electric signal by measuring a change in temperature of thereof, the superconducting transition edge sensor being formed on the board to be a heat sink and comprising a thin film membrane for controlling exhaustion of the heat into the heat sink, a resistor having a superconducting state, a normal conducting state, and an intermediate transition state, for temperature formed on the thin membrane, and electrodes for connection to the external driving circuit.

14. The radiation detector according to claim 12, wherein an absorber is provided on the resistor.