Barium iodide and strontium iodide crystals and scintillators implementing the same

• US 9,507,032 B1
• Filed: 10/07/2013
• Issued: 11/29/2016
• Est. Priority Date: 11/16/2007
• Status: Active Grant

• Current Assignee: Fisk University, Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Inventors: Hull, Giulia E., Payne, Stephen A., Cherepy, Nerine J., Drobshoff, Alexander D., Burger, Arnold
• Primary Examiner(s): Hoban, Matthew E
• Assistant Examiner(s): Edmondson, Lynne
• Application Number:
  US14/047,893
• Publication Number:
  US 20160349383A1
• Time in Patent Office: 1,149 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: C09K 11/7733 with alkali or alkaline earth metals
• CPC Class Codes: C09K 11/7772 Halogenides C09K11/7767 takes precedence
• CPC Class Codes: C09K 11/7791 with alkali or alkaline earth metals
• CPC Class Codes: C30B 11/00 Single-crystal growth by normal freezing or freezing under temperature gradient, e.g. Bridgman-Stockbarger method C30B13/00, C30B15/00, C30B17/00, C30B19/00 take precedence; under a protective fluid C30B27/00
• CPC Class Codes: C30B 29/12 Halides
• CPC Class Codes: G01T 1/202 the detector being a crystal
• CPC Class Codes: G01T 1/2023 Selection of materials see provisionally also G01T1/202
• CPC Class Codes: G21K 4/00 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

Abstract

In one embodiment, a material comprises a crystal comprising strontium iodide providing at least 50,000 photons per MeV, where the strontium iodide material is characterized by a volume not less than 1 cm³. In another embodiment, a scintillator optic includes europium-doped strontium iodide providing at least 50,000 photons per MeV, where the europium in the crystal is primarily Eu²⁺, and the europium is present in an amount greater than about 1.6%. A scintillator radiation detector in yet another embodiment includes a scintillator optic comprising SrI₂ and BaI₂, where a ratio of SrI₂ to BaI₂ is in a range of between 0:1 and 1.0, the scintillator optic is a crystal that provides at least 50,000 scintillation photons per MeV and energy resolution of less than about 5% at 662 keV, and the crystal has a volume of 1 cm³ or more; the scintillator optic contains more than about 2% europium.

Claims

1. A scintillator radiation detector, comprising:

a scintillator optic comprising SrI₂ and BaI₂, wherein a ratio of SrI₂ to BaI₂ is in a range of between 0;

1 and 1;

0,

wherein the scintillator optic is a crystal that provides at least 50,000 scintillation photons per MeV and energy resolution of less than about 5% at 662 keV,

wherein the scintillator optic contains more than 2% europium; and

wherein the scintillator optic contains at least one co-dopant, selected from cerium, praseodymium, thallium, or lead.

2. The scintillator radiation detector of claim 1, wherein the crystal provides an energy resolution of less than about 4% at 662 keV.

3. The scintillator radiation detector of claim 1, wherein the scintillator optic contains more than 2% europium and less than 8% europium.

4. The scintillator radiation detector of claim 3, wherein the europium is primarily Eu²⁺.

5. The scintillator radiation detector of claim 1, wherein the scintillator optic provides at least 80,000 photons per MeV.