Europium doped caesium bromo iodide scintillator and detectors thereof with improved conversion efficiency

Patent metadata

Field	Value
Publication number	US-10067243-B2
Application number	US-201515322493-A
Country	US
Kind code	B2
Filing date	Jun 17, 2015
Priority date	Jul 3, 2014
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

A scintillator includes CsBr x I (1-x) doped with Europium (CsBr x I (1-x) :Eu) wherein x<0.5, and is obtained by annealing CsBr x I (1-x) :Eu material at a temperature from 50° C. to 280° C. The EPR spectrum of the obtained scintillator measured at room temperature at a frequency of 34 GHz shows a maximum signal height at a magnetic field of 1200 mT, and the signal height at 1090 mT and 1140 mT does not exceed 40%, wherein the normalized signal height percentage at 1200 mT is calculated to be 100%. The scintillator is useful in a high energy radiation detection and radiography imaging apparatus.

First claim

The invention claimed is:

1. A method of preparing a scintillator including CsI doped with Eu, the method comprising the steps of:
providing CsI:Eu material by mixing CsI with an Eu containing compound; and
annealing by exposing the CsI:Eu material to heat so as to obtain a temperature from 50° C. to 280° C. for at least 5 min.

2. The method according to claim 1 , wherein the CsI is mixed with the Eu containing compound in a melt.

3. A method of preparing a scintillator screen comprising the steps of:
performing the steps of claim 2 ;
pulverizing the CsI:Eu material before the step of annealing;
following the step of annealing, dispersing the pulverized material in a solution including a binder; and
subsequently coating the dispersion on a substrate.

4. The method of preparing a scintillator screen according to claim 3 , further comprising the step of:
exposing the dispersion coated substrate to electromagnetic radiation having a wavelength between 1 pm and 800 nm.

5. The method according to claim 4 , wherein the electromagnetic radiation is UV-light or visible light and has a dose between 10 and 400000 J/m 2 .

6. A method of making a flat panel detector for radiological image detection, the method comprising the steps of:
performing the steps of claim 3 ; and
coupling the scintillator screen to a detector including a plurality of photosensitive elements which convert light into an electric signal.

7. The method according to claim 1 , further comprising the step of:
exposing the annealed CsI:Eu material to electromagnetic radiation having a wavelength between 1 pm and 800 nm.

8. A method of preparing a scintillator screen comprising the steps of:
performing the steps of claim 7 ; wherein
the CsI is mixed with the Eu containing compound in a gas phase; and
the CsI:Eu material is deposited on a substrate via vapour deposition.

9. A method of preparing a flat panel detector for radiological image detection, the method comprising the steps of:
performing the steps of claim 8 ; and
coupling the deposited CsI:Eu material to a detector including a plurality of photosensitive elements which convert light into an electric signal.

10. The method according to claim 9 , wherein the step of exposing is performed before the step of coupling to the detector.

11. The method according to claim 9 , wherein the electromagnetic radiation is UV-light or visible light and has a dose between 10 and 400000 J/m 2 .

12. A method of preparing a scintillator screen comprising the method steps of:
performing the steps of claim 1 ; wherein
the CsI is mixed with the Eu containing compound in a gas phase; and
the CsI:Eu material is deposited on a substrate via vapour deposition.

13. A method of preparing a flat panel detector for radiological image detection, the method comprising the steps of:
performing the steps of claim 12 ; and
coupling the deposited CsI:Eu material to a detector including a plurality of photosensitive elements which convert light into an electric signal.

14. The method according to claim 13 , wherein the step of annealing is performed after the step of coupling to the detector.

15. A method of preparing a scintillator screen comprising the steps of:
performing the steps of claim 1 ;
pulverizing the CsI:Eu material before the step of annealing;
following the step of annealing, dispersing the pulverized material in a solution including a binder; and
subsequently coating the dispersion on a substrate.

16. A method of making a flat panel detector for radiological image detection, the method comprising the steps of:
performing the steps of claim 15 ; and
coupling the scintillator screen to a detector including a plurality of photosensitive elements which convert light into an electric signal.

17. A method of making a high energy radiation detection apparatus, the method comprising the steps of:
performing the steps of claim 1 ; and
coupling the scintillator with a photocathode of a photo multiplier tube.

Assignees

• Agfa Healthcare Nv

Inventors

• Mans Ilse
• Elen Sabina
• Leblans Paul
• Struye Luc
• Callens Freddy
• Vrielinck Henk

Classifications

• G01T1/2023 Primary

  Selection of materials · CPC title

• G21K4/00

  Conversion screens for the conversion of the spatial distribution of X-rays or particle radiation into visible images, e.g. fluoroscopic screens (photographic processes using X-ray intensifiers G03C5/17; discharge tubes comprising luminescent screens H01J1/62; cathode ray tubes for X-ray conversion with optical output H01J31/50) · CPC title

• G01T1/2006

  using a combination of a scintillator and photodetector which measures the means radiation intensity · CPC title

• C09K11/7733 Primary

  with alkali or alkaline earth metals · CPC title