# US 4,398,093 A · Converter for converting non-luminous photons into luminous photons

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 4,398,093 A
- Document ID: US4398093A
- Status: Granted
- Kind: A
- Application number: 06/176,996
- Filed: 1980-08-11
- Granted: 1983-08-09
- Earliest claimed: 1979-08-14
- Assignees: Etat Francais, represente par le Ministere de l'Environnement et de Cadre de Vie, Laboratoire Central des Ponts et Chaussess
- Inventors: Jean-Claude Dufay
- Web page: https://patentgrep.com/patent/US4398093A

## CPC

- 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)
- G21K: HANDLING OF PARTICLES OR IONISING RADIATION NOT OTHERWISE PROVIDED FOR; IRRADIATION DEVICES; GAMMA RAY OR X-RAY MICROSCOPES

## Abstract

The invention relates to a converter for converting non-luminous, so-called input photons such as X or .gamma. photons, into luminous photons, and to an installation for the non-destructive inspection of a material, employing this converter. The converter comprises a layer of luminophore disposed on the path of said non-luminous photons and, upstream of said layer of luminophore, with respect to the direction of displacement of the non-luminous photons, a metal foil in which said non-luminous photons are converted into non-luminous photons of lower energy, by collision (Compton effect) of said input photons on electrons of said metal foil. The invention is more particularly applicable to the non-destructive inspection of concrete structures.

## Claims

### Claim 1

In a converter for converting non-luminous input photons, such as X or .gamma. photons, into luminous photons, said converter being designed for use in combination with an optical transmitting device and an image display device, said converter being in the form of an independent screen, comprising a support layer, a metal foil in which said non-luminous input photons are converted into non-luminous photons of lower energy, by collision of said input photons on electrons of said metal foil, and a layer of luminophore in which said non-luminous photons of lower energy are converted into luminous photons, the improvement comprising a light-reflecting layer of titanium oxide interposed between said metal foil and said layer of luminophore so as to enhance the luminosity of the converter.

### Claim 2 (depends on 1)

The converter of claim 1, wherein the energy of the non-luminous input photons is substantially between 200 KeV and 10 MeV.

### Claim 3 (depends on 1)

The converter of claim 1, wherein the thickness of the metal foil is between 100 and 500 .mu.m.

### Claim 4 (depends on 1)

The converter of claim 1, wherein the metal foil comprises at least one of the following metals: lead, gold.

### Claim 5 (depends on 1)

The converter of claim 1, wherein the light-reflecting layer has a thickness of about 10 .mu.m.

### Claim 6 (depends on 1)

The converter of claim 1, wherein the luminophore layer is made of ZnS Cd: Ag with a thickness of between 600 and 1500 .mu.m.

### Claim 7 (depends on 1)

The converter of claim 1, wherein the luminophore layer is made of ZnS Cd: Ag with a thickness of about 1000 .mu.m.