Radiation sensitive optical fiber and detector

• US 4,788,436 A
• Filed: 02/12/1988
• Issued: 11/29/1988
• Est. Priority Date: 12/24/1986
• Status: Expired due to Fees

• Current Assignee: Walter Koechner
• Original Assignee: Walter Koechner
• Inventors: Koechner, Walter
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Guss, Paul A.
• Application Number:
  US07/158,072
• Time in Patent Office: 291 Days
• Field of Search: 250/483.1, 250/484.1, 250/485.1, 250/486.1, 250/487.1, 250/227, 250/368, 250/361 R, 350/96.33, 350/96.29, 350/96.30, 350/96.34
• US Class Current: 250/485.1
• CPC Class Codes: G01T 1/201 using scintillating fibres
• CPC Class Codes: G01T 1/203 the detector being made of plastics
• CPC Class Codes: G02B 6/02 Optical fibres with cladding with or without a coating
• CPC Class Codes: G02B 6/262 Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements
• CPC Class Codes: G02B 6/2821 using lateral coupling between contiguous fibres to split or combine optical signals
• CPC Class Codes: G02B 6/34 utilising prism or grating G02B6/293 takes precedence

Abstract

An optical fiber sensitive to nuclear radiation includes a thin filament core formed of a plastic scintillator material which scintillates in the presence of nuclear radiation. An optical cladding material is provided around the optical fiber. A second fiber is connected to the optical fiber for efficiently transmitting the scintillating light from the optical fiber to a radiation detector.

Claims

1. An optical fiber sensitive to nuclear radiation, comprising:

a thin and elongated filament core which is scintillatable in the presence of the nuclear radiation, said core comprising a plastic material selected from the group consisting of polyvinyltoluene doped with organic scintillator material and styrene doped with organic scintillator material, said organic scintillator material being selected from the group consisting of 2,5-diphenyl- oxazole (PPO) and bis-MSB p-bis-(0-methyl-styryl) - benzene, dimethyl-POPOP and POPOP, wherein POPOP is the name for the organic material P-bis-benzene;

an optical cladding surrounding said filament core, said cladding comprising a low refractive index plastic material consisting of polymethylacrylate; and

an outer layer of opaque plastic material surrounding said optical cladding.

2. An optical fiber assembly highly sensitive to nuclear radiation, comprising:

a thin and elongated filament core which is scintillatable in the presence of the nuclear radiation;

an optical cladding surrounding said filament core;

an outer layer of opaque plastic material surrounding said optical cladding and overlying one end of said core;

said core and said cladding comprising plastic materials which are chemically inert and incapable of copolymerizing and have essentially the same melting temperature;

said cladding having a lower index of refraction than that of said core and having a low loss in optical wavelength;

said core material being selected from the group consisting of polyvinyltoluene doped with organic scintillator material and styrene doped with organic scintillator material, said organic scintillator material being selected from the group consisting of 2,5-diphenyl- oxazole (PPO) and bis-MSB p-bis-(0-methy-styryl) - benzene, dimethyl-POPOP and POPOP, wherein POPOP is the name for the organic material P-bis-benzene;

said cladding material consisting of polymethylacrylate; and

a fiber optically connnected to an opposite end of said filament core and adapted to efficiently propagate ultraviolet radiation therethrough.

3. A detector for perimeter or area detection of nuclear radiation, comprising a plurality of first fibers each having a thin and elongated filament core which is scintillatable in the presence of the nuclear radiation to provide a signal corresponding to the nuclear radiation, an optical cladding surrounding each said filament core, an outer layer of opaque plastic material surrounding said optical cladding and overlying one end of each said core, said first fibers being respectively connected at each opposite end thereof to a plurality of second fibers each for efficiently transmitting ultraviolet radiation for improved propagation of said signal, a detector unit connected to said second fibers, said core and said cladding comprising plastic materials which are chemically inert and incapable of copolymerizing and have essentially the same melting temperature, said cladding having a lower index of refraction than that of said core and having a low loss in optical wavelength, said core material being selected from the group consisting of polyvinyltoluene doped with organic scintillator material and styrene doped with organic scintillator material, said organic scintillator material being selected from the group consisting of 2,5-diphenyl- oxazole (PPO) and bis-MSB p-bis-(0-methyl-styryl)-benzene, dimethyl-POPOP and POPOP, wherein POPOP is the name for the organic material P-bis-benzene, said cladding material consisting of polymethylacrylate.