US6706212B2
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US
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Cerium-doped alkaline-earth hafnium oxide scintillators having improved transparency and method of making the same
Assignee: General Electric Co
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Filing: 2002-04-12
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Granted: 2004-03-16
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Expires: 2022-04-12
Abstract
Abstract Cerium-doped alkaline-earth hafnium oxide scintillator compositions have at least one alkaline earth metal selected from the group consisting of Ba, Sr, Ca, and combinations thereof. The scintillator compositions can be formed into a shape having porosity less than about 0.05 percent for improved transparency. The alkaline earth metal can be partially substituted with divalent and/or trivalent ions other than cerium. Hafnium can be partially substituted with divalent, trivalent, and/or tetravalent ions. The scintillators are characterized by high light output, short decay time, and high radiation stopping power. The scintillators can be used as detector elements in PET systems.
Inventors
- 👤 Venkat Subramaniam Venkataramani
- 👤 Sergio Martins Loureiro
- 👤 Manisha Vishwanath Rane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 20:19
CPC Classifications
C; C09; C09K; C09K11/00; C09K11/08; C09K11/77; C09K11/7766; C09K11/7767; C09K11/7768; C04; C04B; C04B35/00; C04B35/01; C04B35/48; C04B35/486; C04B35/622; C04B35/626; C04B35/62605; C04B35/62645; C04B35/6268; C04B35/62685; C04B35/64; C04B35/645; C04B35/6455; C09K11/7715; C09K11/7716; C09K11/7718; A; A61; A61B; A61B6/00; A61B6/02; A61B6/03; A61B6/037; C04B2235/00; C04B2235/02; C04B2235/30; C04B2235/32; C04B2235/3205; C04B2235/3208; C04B2235/3213; C04B2235/3215; C04B2235/3217; C04B2235/3224; C04B2235/3227; C04B2235/3229; C04B2235/3231; C04B2235/3232; C04B2235/3244; C04B2235/3248; C04B2235/3286; C04B2235/3287; C04B2235/3293; C04B2235/34; C04B2235/3418; C04B2235/44; C04B2235/449; C04B2235/65; C04B2235/658; C04B2235/6582; C04B2235/66; C04B2235/661; C04B2235/662; C04B2235/664; C04B2235/70; C04B2235/74; C04B2235/77
Claims Analysis
Total Claims: 76
Claim 1
Independent Claim
86 words
A scintillator composition comprising alkaline earth hafnium oxide doped with cerium, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkaline earth metal and said hafnium is from about 0.9 to about 1.1; said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency, and wherein said scintillator composition is a polycrystalline material.
Claim 2
Dependent Claim
86 words
A scintillator composition comprising alkaline earth hafnium oxide doped with cerium, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkaline earth metal and said hafnium is from about 0.9 to about 1.1; said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency, and wherein said scintillator composition is a polycrystalline material.
Claim 3
Dependent Claim
20 words
The scintillator composition according to claim 1 , wherein said polycrystalline material has a porosity less than about 0.05 percent.
Claim 4
Dependent Claim
29 words
The scintillator composition according to claim 1 , wherein said polycrystalline material has a density in a range from about 7.7 g/cm 3 to about 8.4 g/cm 3 .
Claim 5
Dependent Claim
125 words
A scintillator composition comprising alkaline earth hafnium oxide doped with cerium, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkaline earth metal and said hafnium is from about 0.9 to about 1.1; said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency, said scintillator composition further comprising at least a trivalent ion other than cerium and having a formula of Al 1−x−y M III x Ce y Hf 1−(x+y)/4 O 3 wherein 0<x0.5, 0<y≦0.05, A is said alkaline earth metal, and M III is a trivalent ion other than cerium.
Claim 6
Dependent Claim
125 words
A scintillator composition comprising alkaline earth hafnium oxide doped with cerium, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkaline earth metal and said hafnium is from about 0.9 to about 1.1; said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency, said scintillator composition further comprising at least a trivalent ion other than cerium and having a formula of Al 1−x−y M III x Ce y Hf 1−(x+y)/4 O 3 wherein 0<x0.5, 0<y≦0.05, A is said alkaline earth metal, and M III is a trivalent ion other than cerium.
Claim 7
Dependent Claim
24 words
The scintillator composition according to claim 4 , wherein M III is selected from the group consisting of lanthanum, gadolinium, lutetium, and combinations thereof.
Claim 8
Dependent Claim
123 words
A scintillator composition comprising alkaline earth hafnium oxide doped with cerium, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkaline earth metal and said hafnium is from about 0.9 to about 1.1; said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency, said scintillator composition further comprising at least a trivalent ion other than cerium and having a formula of A 1−3x−3y M III 2x Ce 2y HfO 3 wherein 0<x0.1, 0<y≦0.025, A is said alkaline earth metal, and M III is a trivalent ion other than cerium.
Claim 9
Dependent Claim
123 words
A scintillator composition comprising alkaline earth hafnium oxide doped with cerium, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkaline earth metal and said hafnium is from about 0.9 to about 1.1; said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency, said scintillator composition further comprising at least a trivalent ion other than cerium and having a formula of A 1−3x−3y M III 2x Ce 2y HfO 3 wherein 0<x0.1, 0<y≦0.025, A is said alkaline earth metal, and M III is a trivalent ion other than cerium.
Claim 10
Dependent Claim
24 words
The scintillator composition according to claim 6 , wherein M III is selected from the group consisting of lanthanum, gadolinium, lutetium, and combinations thereof.
Claim 11
Dependent Claim
125 words
A scintillator composition comprising alkaline earth hafnium oxide doped with cerium, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkaline earth metal and said hafnium is from about 0.9 to about 1.1; said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency, said scintillator composition further comprising at least a trivalent ion other than cerium and having a formula of A 1−y Ce y Hf 1−z M III z O 3 wherein 0<y≦0.05, 0<z≦0.05, A is said alkaline earth metal, and M III is a trivalent ion other than cerium.
Claim 12
Dependent Claim
125 words
A scintillator composition comprising alkaline earth hafnium oxide doped with cerium, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkaline earth metal and said hafnium is from about 0.9 to about 1.1; said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency, said scintillator composition further comprising at least a trivalent ion other than cerium and having a formula of A 1−y Ce y Hf 1−z M III z O 3 wherein 0<y≦0.05, 0<z≦0.05, A is said alkaline earth metal, and M III is a trivalent ion other than cerium.
Claim 13
Dependent Claim
28 words
The scintillator composition according to claim 8 , wherein M III is selected from the group consisting of lutetium, ytterbium, gadolinium, holmium, aluminum, gallium, indium, and combinations thereof.
Claim 14
Dependent Claim
23 words
The scintillator composition according to claim 8 , wherein M III is selected from the group consisting of lutetium, aluminum, and combinations thereof.
Claim 15
Dependent Claim
13 words
The scintillator composition according to claim 10 , wherein M III is lutetium.
Claim 16
Dependent Claim
13 words
The scintillator composition according to claim 10 , wherein M III is aluminum.
Claim 17
Dependent Claim
120 words
A scintillator composition comprising alkaline earth hafnium oxide doped with cerium, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium and combinations thereof and an atomic ratio of said alkaline earth metal and said hafnium is from about 0.9 to about 1.1; said scintillator being capable of emitting X, β and γ radiation and having improved light transparency, said scintillator composition further comprising at least one tetravalent ion and having the formula of A 1−y Ce y Hf 1−z M IV z O 3 wherein 0<y≦0.05, A is said alkaline earth metal, 0<z≦0.05 and M IV is a tetravalent ion selected from the group consisting of tin, tellurium, titanium, germanium, silicon and combinations thereof.
Claim 18
Dependent Claim
120 words
A scintillator composition comprising alkaline earth hafnium oxide doped with cerium, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium and combinations thereof and an atomic ratio of said alkaline earth metal and said hafnium is from about 0.9 to about 1.1; said scintillator being capable of emitting X, β and γ radiation and having improved light transparency, said scintillator composition further comprising at least one tetravalent ion and having the formula of A 1−y Ce y Hf 1−z M IV z O 3 wherein 0<y≦0.05, A is said alkaline earth metal, 0<z≦0.05 and M IV is a tetravalent ion selected from the group consisting of tin, tellurium, titanium, germanium, silicon and combinations thereof.
Claim 19
Dependent Claim
139 words
A scintillator composition comprising alkaline earth hafnium oxide doped with cerium, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkaline earth metal and said hafnium is from about 0.9 to about 1.1; said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency, said scintillator composition further comprising at least a trivalent ion other than cerium and a divalent ion, and having a formula of A 1−2y−2v Ce 2y M III 2v Hf 1−y−v M II y+v O 3 wherein 0<y≦0.025, 0.1 <v≦0.1, A is said alkaline earth metal, M III is a trivalent ion other than cerium, and M II is a divalent ion.
Claim 20
Dependent Claim
139 words
A scintillator composition comprising alkaline earth hafnium oxide doped with cerium, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkaline earth metal and said hafnium is from about 0.9 to about 1.1; said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency, said scintillator composition further comprising at least a trivalent ion other than cerium and a divalent ion, and having a formula of A 1−2y−2v Ce 2y M III 2v Hf 1−y−v M II y+v O 3 wherein 0<y≦0.025, 0.1 <v≦0.1, A is said alkaline earth metal, M III is a trivalent ion other than cerium, and M II is a divalent ion.
Claim 21
Dependent Claim
39 words
The scintillator composition according to claim 14 , wherein M III is selected from the group consisting of lanthanum, gadolinium, lutetium, and combinations thereof; and M II is selected from the group consisting of magnesium, calcium, and combinations thereof.
Claim 22
Independent Claim
183 words
A method for producing a cerium-doped alkaline earth hafnium oxide scintillator composition that comprises at least one alkaline earth metal selected from the group consisting of barium, strontium, calcium, and combinations thereof; said method comprising the steps of: providing a mixture of compounds of cerium, hafnium, and said at least one alkaline earth metal; firing said mixture in en oxygen-containing atmosphere at a firing temperature for a time sufficient to convert said mixture to a cerium-doped alkaline earth hafnium oxide; pulverizing paid cerium-doped alkaline earth hafnium oxide to micrometer-sized particles having a size of less than about 2 micrometers; subjecting said micrometer-sized particles to a procedure selected from the group consisting of hot pressing and hot isostatic pressing to form a shaped scintillator composition; and annealing said shaped scintillator composition to produce said cerium-doped alkaline earth hafnium oxide scintillator composition; wherein amounts of compounds are chosen to obtain the final desired composition of said scintillator, and said scintillator is capable of emitting visible light in response to an excitation of high-energy radiation selected from the group consisting of X, β, and γ radiation.
Claim 23
Independent Claim
183 words
A method for producing a cerium-doped alkaline earth hafnium oxide scintillator composition that comprises at least one alkaline earth metal selected from the group consisting of barium, strontium, calcium, and combinations thereof; said method comprising the steps of: providing a mixture of compounds of cerium, hafnium, and said at least one alkaline earth metal; firing said mixture in en oxygen-containing atmosphere at a firing temperature for a time sufficient to convert said mixture to a cerium-doped alkaline earth hafnium oxide; pulverizing paid cerium-doped alkaline earth hafnium oxide to micrometer-sized particles having a size of less than about 2 micrometers; subjecting said micrometer-sized particles to a procedure selected from the group consisting of hot pressing and hot isostatic pressing to form a shaped scintillator composition; and annealing said shaped scintillator composition to produce said cerium-doped alkaline earth hafnium oxide scintillator composition; wherein amounts of compounds are chosen to obtain the final desired composition of said scintillator, and said scintillator is capable of emitting visible light in response to an excitation of high-energy radiation selected from the group consisting of X, β, and γ radiation.
Claim 24
Dependent Claim
39 words
The method according to claim 16 , wherein said providing further comprises providing amounts of compounds of at least an ion selected from the group consisting of divalent ions, trivalent ions other than cerium, tetravalent ions, and combinations thereof.
Claim 25
Dependent Claim
39 words
The method according to claim 16 , wherein said firing in said oxygen-containing atmosphere is carried out at a temperature in a range from about 900° C. to about 1300° C. for a time of up to 10 hours.
Claim 26
Dependent Claim
32 words
The method according to claim 16 , wherein said firing in said oxygen-containing atmosphere is preferably carried out at a temperature in a range from about 1000° C. to about 1200° C.
Claim 27
Dependent Claim
26 words
The method according to claim 16 , wherein said annealing is conducted at a temperature in a range from about 1600° C. to about 1900° C.
Claim 28
Independent Claim
165 words
A method for producing a shaped cerium-doped alkaline earth hafnium oxide scintillator that comprises at least one alkaline earth metal selected from the group consisting of barium, strontium, calcium, and combinations thereof, said method comprising the steps of: providing a starting mixture of compounds of cerium, hafnium, and said at least one alkaline earth metal; converting said compounds In said starting mixture substantially to water-insoluble oxygen-containing compounds to form a mixture of water-insoluble oxygen-containing compounds; firing said mixture of said oxygen-containing compounds at a firing temperature for a time sufficient to convert said mixture to a cerium-doped alkaline earth hafnium oxide; and hot isostatically pressing said cerium-doped alkaline earth hafnium oxide to form said shaped cerium-doped alkaline earth hafnium oxide scintillator; wherein amounts of said compounds are chosen to obtain a final desired composition of said scintillator, and said scintillator is capable of emitting visible light in response to an excitation of high-energy radiation selected from the group consisting of X, β, and γ radiation.
Claim 29
Independent Claim
165 words
A method for producing a shaped cerium-doped alkaline earth hafnium oxide scintillator that comprises at least one alkaline earth metal selected from the group consisting of barium, strontium, calcium, and combinations thereof, said method comprising the steps of: providing a starting mixture of compounds of cerium, hafnium, and said at least one alkaline earth metal; converting said compounds In said starting mixture substantially to water-insoluble oxygen-containing compounds to form a mixture of water-insoluble oxygen-containing compounds; firing said mixture of said oxygen-containing compounds at a firing temperature for a time sufficient to convert said mixture to a cerium-doped alkaline earth hafnium oxide; and hot isostatically pressing said cerium-doped alkaline earth hafnium oxide to form said shaped cerium-doped alkaline earth hafnium oxide scintillator; wherein amounts of said compounds are chosen to obtain a final desired composition of said scintillator, and said scintillator is capable of emitting visible light in response to an excitation of high-energy radiation selected from the group consisting of X, β, and γ radiation.
Claim 30
Dependent Claim
26 words
The method according to claim 21 further comprising calcining said cerium-doped alkaline earth hafnium oxide under a reducing atmosphere before the step of hot isostatically pressing.
Claim 31
Dependent Claim
24 words
The method according to claim 21 further comprising annealing said shaped cerium-doped alkaline earth hafnium oxide scintillator after the step of hot isostatically pressing.
Claim 32
Dependent Claim
36 words
The method according to claim 22 further comprising annealing said cerium-doped alkaline earth hafnium oxide scintillator after the step of calcining said cerium-doped alkaline earth hafnium oxide scintillator and before the step of hot isostatic pressing.
Claim 33
Dependent Claim
36 words
The method according to claim 21 , wherein said mixture further comprises compounds of at least an ion selected from the group consisting of divalent ions, trivalent ions other than cerium, tetravalent ions, and combinations thereof.
Claim 34
Dependent Claim
61 words
The method according to claim 21 , wherein said compounds are selected from the group consisting of oxides, carbonates, nitrates, halides, oxyhalides, oxynitrates, sulfates, salts of mono- and di-carboxylic acids containing 1 to 6 carbon atoms, esters of di-carboxylic acids containing 1 to 6 carbon atoms, salts of aromatic acids containing up to 2 aromatic rings, acetylacetonates, alkoxides, and mixtures thereof.
Claim 35
Independent Claim
215 words
A method for producing a cerium-doped alkaline earth hafnium oxide scintillator composition that comprises at least one alkaline earth metal selected from the group consisting of barium, strontium, calcium, and combinations thereof; said method comprising the steps of; providing a first solution comprising compounds of at least cerium, hafnium, and said at least one alkaline earth metal; providing a second solution selected from the group consisting of ammonium hydroxide; alkyl esters of a di-carboxylic acid selected from the group consisting of oxalic acid, malonic acid, succinic acid, and glutaric acid; amines selected from the group consisting of methanolamine, ethanolamine, propanolamine, dimethanolamine, diethanolamine, dipropanolamine, trimethanolamine, triethanolamine, and tripropanolamine; and mixtures thereof; mixing together said first solution and said second solution to form a precipitate mixture of oxygen-containing compounds of at least cerium, hafnium, and said at least one alkaline earth metal; separating said precipitate mixture from a supernatant liquid; firing said precipitate mixture at a temperature and for a time sufficient to convert said dried precipitate mixture to said cerium-doped hafnium oxide scintillator composition; wherein amounts of said compounds are chosen to obtain a final desired composition of said scintillator that is capable of emitting visible light in response to an excitation of high-energy radiation selected from the group consisting of X, β, and γ radiation.
Claim 36
Independent Claim
215 words
A method for producing a cerium-doped alkaline earth hafnium oxide scintillator composition that comprises at least one alkaline earth metal selected from the group consisting of barium, strontium, calcium, and combinations thereof; said method comprising the steps of; providing a first solution comprising compounds of at least cerium, hafnium, and said at least one alkaline earth metal; providing a second solution selected from the group consisting of ammonium hydroxide; alkyl esters of a di-carboxylic acid selected from the group consisting of oxalic acid, malonic acid, succinic acid, and glutaric acid; amines selected from the group consisting of methanolamine, ethanolamine, propanolamine, dimethanolamine, diethanolamine, dipropanolamine, trimethanolamine, triethanolamine, and tripropanolamine; and mixtures thereof; mixing together said first solution and said second solution to form a precipitate mixture of oxygen-containing compounds of at least cerium, hafnium, and said at least one alkaline earth metal; separating said precipitate mixture from a supernatant liquid; firing said precipitate mixture at a temperature and for a time sufficient to convert said dried precipitate mixture to said cerium-doped hafnium oxide scintillator composition; wherein amounts of said compounds are chosen to obtain a final desired composition of said scintillator that is capable of emitting visible light in response to an excitation of high-energy radiation selected from the group consisting of X, β, and γ radiation.
Claim 37
Dependent Claim
39 words
The method according to claim 27 , wherein said first solution further comprises amounts of compounds of at least an ion selected from the group consisting of divalent ions, trivalent ions other than cerium, tetravalent ions, and combinations thereof.
Claim 38
Dependent Claim
30 words
The method according to claim 27 further comprising the step of calcining said cerium-doped alkaline earth hafnium oxide scintillator composition in a reducing atmosphere to produce a calcined scintillator material.
Claim 39
Dependent Claim
39 words
The method according to claim 27 , wherein said firing is carried out in an oxygen-containing atmosphere at a temperature in a range from about 900° C. to about 1500° C. for a time of up to 10 hours.
Claim 40
Dependent Claim
32 words
The method according to claim 27 , wherein said firing in said oxygen-containing atmosphere is preferably carried out at a temperature in a range from about 1000° C. to about 1500° C.
Claim 41
Dependent Claim
35 words
The method according to claim 29 , wherein said calcining is carried out at a temperature in a range from about 1000° C. to about 1600° C. for a time of up to 10 hours.
Claim 42
Dependent Claim
28 words
The method according to claim 29 , wherein said calcining is carried out at a temperature in a range from about 1000° C. to about 1500 ° C.
Claim 43
Dependent Claim
23 words
The method according to claim 27 further comprising the step of sintering said scintillator composition after firing to produce a sintered scintillator composition.
Claim 44
Dependent Claim
17 words
The method according to claim 34 further comprising the step of annealing said sintered composition after sintering.
Claim 45
Independent Claim
232 words
A method for producing a shaped cerium-doped alkaline earth hafnium oxide scintillator that comprises at least one alkaline earth metal selected from the group consisting of barium, strontium, calcium, and combinations thereof, said method comprising the steps of: providing a first solution that comprises amounts of compounds of at least cerium, hafnium, and said at least one alkaline earth metal; providing a second solution selected from the group consisting of ammonium hydroxide; alkyl esters of a di-carboxylic acid selected from the group consisting of oxalic acid, malonic acid, succinic acid, and glutaric acid; amines selected from the group consisting of methanolamine, ethanolamine, propanolamine, dimethanolamine, diethanolamine, dipropanolamine, trimethanolamine, triethanolamine, and tripropanolamine; and mixtures thereof; mixing together said first solution and said second solution to form a precipitate mixture of oxygen-containing compounds of at least cerium, hafnium, and said at least one alkaline earth metal; separating said precipitate mixture from a supernatant liquid; firing said precipitate mixture at a temperature and for a time sufficient to convert said precipitate mixture to a cerium-doped hafnium oxide; and hot isostatically pressing said cerium-doped hafnium oxide to form said shaped cerium-doped alkaline earth hafnium oxide scintillator; wherein amounts of compounds are chosen to obtain a final desired composition of said scintillator that is capable of emitting visible light in response to an excitation of high-energy radiation selected from the group consisting of X, β, and γ radiation.
Claim 46
Independent Claim
232 words
A method for producing a shaped cerium-doped alkaline earth hafnium oxide scintillator that comprises at least one alkaline earth metal selected from the group consisting of barium, strontium, calcium, and combinations thereof, said method comprising the steps of: providing a first solution that comprises amounts of compounds of at least cerium, hafnium, and said at least one alkaline earth metal; providing a second solution selected from the group consisting of ammonium hydroxide; alkyl esters of a di-carboxylic acid selected from the group consisting of oxalic acid, malonic acid, succinic acid, and glutaric acid; amines selected from the group consisting of methanolamine, ethanolamine, propanolamine, dimethanolamine, diethanolamine, dipropanolamine, trimethanolamine, triethanolamine, and tripropanolamine; and mixtures thereof; mixing together said first solution and said second solution to form a precipitate mixture of oxygen-containing compounds of at least cerium, hafnium, and said at least one alkaline earth metal; separating said precipitate mixture from a supernatant liquid; firing said precipitate mixture at a temperature and for a time sufficient to convert said precipitate mixture to a cerium-doped hafnium oxide; and hot isostatically pressing said cerium-doped hafnium oxide to form said shaped cerium-doped alkaline earth hafnium oxide scintillator; wherein amounts of compounds are chosen to obtain a final desired composition of said scintillator that is capable of emitting visible light in response to an excitation of high-energy radiation selected from the group consisting of X, β, and γ radiation.
Claim 47
Dependent Claim
40 words
The method according to claim 36 , wherein said first solution further comprises at least a compound of at least an ion selected from the group consisting of divalent ions, trivalent ions other than cerium, tetravalent ions, and combinations thereof.
Claim 48
Dependent Claim
27 words
The method according to claim 36 , wherein said firing is followed by a step of calcining said cerium-doped alkaline earth hafnium oxide in a reducing atmosphere.
Claim 49
Dependent Claim
24 words
The method according to claim 36 further comprising annealing said shaped cerium-doped alkaline earth hafnium oxide scintillator after the step of hot isostatically pressing.
Claim 50
Dependent Claim
29 words
The method according to claim 38 further comprising annealing said cerium-doped alkaline earth hafnium oxide scintillator after the step of calcining and before the step of hot isostatically pressing.
Claim 51
Dependent Claim
27 words
The method according to claim 36 , wherein said firing is conducted at a firing temperature in a range from about 900° C. to about 1500° C.
Claim 52
Dependent Claim
24 words
The method according to claim 36 , wherein said firing temperature is preferably in a range from about 1000° C. to about 1400° C.
Claim 53
Dependent Claim
27 words
The method according to claim 38 , wherein said calcining temperature is conducted at a temperature in a range from about 1000° C. to about 1600° C.
Claim 54
Dependent Claim
34 words
The method according to claim 36 , wherein said calcining temperature is preferably in a range from about 1000° C. to about 1500° C. more preferably from about 1000° C. to about 1450° C.
Claim 55
Dependent Claim
86 words
A detector element of a positron emission tomography (“PET”) scanner comprising a cerium-doped alkaline earth hafnium oxide scintillator composition, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkali earth metal and said hafnium is from about 0.9 to about 1.1; and said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency.
Claim 56
Dependent Claim
86 words
A detector element of a positron emission tomography (“PET”) scanner comprising a cerium-doped alkaline earth hafnium oxide scintillator composition, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkali earth metal and said hafnium is from about 0.9 to about 1.1; and said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency.
Claim 57
Dependent Claim
83 words
A detector element of a PET scanner comprising a cerium-doped alkaline earth hafnium oxide scintillator composition, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkali earth metal and said hafnium is from about 0.95 to about 1.05; and said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency.
Claim 58
Dependent Claim
83 words
A detector element of a PET scanner comprising a cerium-doped alkaline earth hafnium oxide scintillator composition, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkali earth metal and said hafnium is from about 0.95 to about 1.05; and said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency.
Claim 59
Dependent Claim
20 words
A detector element of a PET scanner comprising a cerium-doped alkaline earth hafnium oxide scintillator composition of claim 2 .
Claim 60
Dependent Claim
20 words
A detector element of a PET scanner comprising a cerium-doped alkaline earth hafnium oxide scintillator composition of claim 3 .
Claim 61
Dependent Claim
20 words
A detector element of a PET scanner comprising a cerium-doped alkaline earth hafnium oxide scintillator composition of claim 4 .
Claim 62
Dependent Claim
20 words
A detector element of a PET scanner comprising a cerium-doped alkaline earth hafnium oxide scintillator composition of claim 6 .
Claim 63
Dependent Claim
20 words
A detector element of a PET scanner comprising a cerium-doped alkaline earth hafnium oxide scintillator composition of claim 8 .
Claim 64
Dependent Claim
20 words
A detector element of a PET scanner comprising a cerium-doped alkaline earth hafnium oxide scintillator composition of claim 13 .
Claim 65
Dependent Claim
20 words
A detector element of a PET scanner comprising a cerium-doped alkaline earth hafnium oxide scintillator composition of claim 14 .
Claim 66
Dependent Claim
84 words
A PET scanner comprising an X-ray detector that comprises a cerium-doped alkaline earth hafnium oxide scintillator composition, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkali earth metal and said hafnium is from about 0.9 to about 1.1; and said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency.
Claim 67
Dependent Claim
84 words
A PET scanner comprising an X-ray detector that comprises a cerium-doped alkaline earth hafnium oxide scintillator composition, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkali earth metal and said hafnium is from about 0.9 to about 1.1; and said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency.
Claim 68
Dependent Claim
84 words
A PET scanner comprising an X-ray detector that comprises a cerium-doped alkaline earth hafnium oxide scintillator composition, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkali earth metal and said hafnium is from about 0.95 to about 1.05; and said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency.
Claim 69
Dependent Claim
84 words
A PET scanner comprising an X-ray detector that comprises a cerium-doped alkaline earth hafnium oxide scintillator composition, wherein said alkaline earth metal is selected from the group consisting of barium, strontium, calcium, and combinations thereof; and an atomic ratio of said alkali earth metal and said hafnium is from about 0.95 to about 1.05; and said scintillator being capable of emitting visible light in response to high-energy radiation selected from the group consisting of X, β, and γ radiation and having improved light transparency.
Claim 70
Dependent Claim
21 words
A PET scanner comprising an X-ray detector that comprises a cerium-doped alkaline earth hafnium oxide scintillator composition of claim 2 .
Claim 71
Dependent Claim
21 words
A PET scanner comprising an X-ray detector that comprises a cerium-doped alkaline earth hafnium oxide scintillator composition of claim 3 .
Claim 72
Dependent Claim
21 words
A PET scanner comprising an X-ray detector that comprises a cerium-doped alkaline earth hafnium oxide scintillator composition of claim 4 .
Claim 73
Dependent Claim
21 words
A PET scanner comprising an X-ray detector that comprises a cerium-doped alkaline earth hafnium oxide scintillator composition of claim 6 .
Claim 74
Dependent Claim
21 words
A PET scanner comprising an X-ray detector that comprises a cerium-doped alkaline earth hafnium oxide scintillator composition of claim 8 .
Claim 75
Dependent Claim
21 words
A PET scanner comprising an X-ray detector that comprises a cerium-doped alkaline earth hafnium oxide scintillator composition of claim 13 .
Claim 76
Dependent Claim
21 words
A PET scanner comprising an X-ray detector that comprises a cerium-doped alkaline earth hafnium oxide scintillator composition of claim 14 .
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2007-03-16 | 2007-09-15 | 2008-03-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-03-16 | 2011-09-15 | 2012-03-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-03-16 | 2015-09-15 | 2016-03-16 | $7700.00 | Window Closed / Lapsed |