Solid scintillator and electron beam detector using the same
The present invention provides a solid scintillator comprising a rare earth oxide sintered body, wherein: an afterglow time, which is the time required for a light output from the solid scintillator to degrease from a maximum value to 1/e of the maximum value, is 200 ns or shorter. The rare earth oxide sintered body preferably has a composition represented by a general formula (1): Ln a X b O c :Ce (1), wherein Ln is one or more elements selected from Y, Gd and Lu; X is one or more elements selected from Si, Al and B; and a, b and c satisfy 1≦a≦5, 0.9≦b≦6, and 2.5≦≦c≦13, respectively.
1. A solid scintillator comprising a rare earth oxide sintered body, wherein:
an afterglow time, which is the time required for a light output from the solid scintillator to degrease from a maximum value to 1/e of the maximum value, is 200 ns or shorter, and
the rare earth oxide sintered body has a composition represented by a following general formula (1):
[Formula 1]
Ln a X b O c :Ce (1)
wherein Ln is one or more elements selected from Y, Gd and Lu; X is one or more elements selected from Si, Al and B; and a, b and c satisfy 1≦a≦5, 0.9≦b≦6, and 2.5≦c≦13, respectively.
2. The solid scintillator according to claim 1 , wherein the rare earth oxide sintered body has a composition represented by a following general formula (2):
[Formula 2]
Y 2 O 3 .β 1 SiO 2 :Ce (2)
wherein β 1 satisfies 0.95<β 1 <1.05.
3. The solid scintillator according to claim 1 , wherein the rare earth oxide sintered body has a composition represented by a following general formula (3):
[Formula 3]
α 2 Y 2 O 3 .β 2 Al 2 O 3 :Ce (3)
wherein α 2 and β 2 satisfy 1.45<α 2 <1.55 and 2.45<β 2 <2.55, respectively.
4. The solid scintillator according to claim 1 , wherein the rare earth oxide sintered body has a composition represented by a following general formula (4):
[Formula 4]
α 3 Y 2 O 3 .β 3 Al 2 O 3 :Ce (4)
wherein α 3 and β 3 satisfy 0.45<α 3 <0.55 and 0.45<β 3 <0.55, respectively.
5. The solid scintillator according to claim 1 , wherein the rare earth oxide sintered body has a composition represented by a following general formula (5):
[Formula 5]
α 4 Y 2 O 3 .β 4 Al 2 O 3 :Ce,Pr (5)
wherein α 4 and β 4 satisfy 0.45<α 4 <0.55 and 0.45<β 4 <0.55, respectively.
6. The solid scintillator according to claim 1 , wherein the rare earth oxide sintered body has a composition represented by a following general formula (6):
[Formula 6]
0.8Gd 2 O 3 .0.2Y 2 O 3 .β 5 SiO 2 :Ce (6)
wherein β 5 satisfies 0.95<β 5 <1.05.
7. The solid scintillator according to claim 1 , wherein the rare earth oxide sintered body has an average crystal particle size of 1 to 20 μm.
8. The solid scintillator according to claim 1 , wherein the rare earth oxide sintered body has a relative density of 99% or more.
9. The solid scintillator according to claim 1 , wherein surface roughness Ra of an output surface outputting light to a photoelectron multiplier tube side is 0.3 to 10 μm.
10. An electron beam detector using a solid scintillator according to claim 1 .
11. The electron beam detector according to claim 10 comprising a photoelectron multiplier tube.
12. The electron beam detector according to claim 10 , wherein the electron beam detector is used in a SEM apparatus.