Microchannel plate streak camera

• US 4,814,599 A
• Filed: 08/06/1987
• Issued: 03/21/1989
• Est. Priority Date: 09/28/1984
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Department Of Energy
• Original Assignee: United States Department of Energy
• Inventors: Wang, Ching L.
• Primary Examiner(s): Nelms, David C.
• Application Number:
  US07/083,014
• Time in Patent Office: 593 Days
• Field of Search: 313/103 CM, 313/105 CM, 313/524, 313/534, 250/213 UT, 250/207, 358/111, 378/99
• US Class Current: 250/214.0VT
• CPC Class Codes: H01J 31/502 with means to interrupt the beam, e.g. shutter for high speed photography circuits using electron-beam shutters G03B27/725
• CPC Class Codes: H01J 31/507 using a large number of channels, e.g. microchannel plates

Abstract

An improved streak camera in which a microchannel plate electron multiplier is used in place of or in combination with the photocathode used in prior streak cameras. The improved streak camera is far more sensitive to photons (UV to gamma-rays) than the conventional x-ray streak camera which uses a photocathode. The improved streak camera offers gamma-ray detection with high temporal resolution. It also offers low-energy x-ray detection without attenuation inside the cathode. Using the microchannel plate in the improved camera has resulted in a time resolution of about 150 ps, and has provided a sensitivity sufficient for 1000 KeV x-rays.

Claims

1. A method for increasing the sensitivity of a streak camera containing a photocathode sensitive to photons in the ultra-violet to gamma-ray range,

comprising the step of:

substituting a microchannel plate electron multiplier for the photocathode in said camera for receiving x-rays and gamma-rays from a source.

2. An instrument sensitive enough for measuring x-rays having an energy of at least 100 KeV comprising:

a housing having an opening therein,

a microchannel plate positioned in said opening of said housing,

an extractor positioned in said opening and adjacent said microchannel plate,

a focusing the electrode positioned in said opening and adjacent said extractor,

an anode positioned in said opening and adjacent said focusing electrode,

a deflector positioned in said opening and adjacent said anode,

a phospher plate positioned in said opening and adjacent said deflector,

optical fibers located in said opening and adjacent said phospher plate,

a microchannel plate intensifier located in said opening and adjacent said optical fibers,

a film positioned in said opening and adjacent said intensifier, and

an ion pump operatively connected to said opening of said housing at a point intermediate said extractor and said focusing electrode.

3. The instrument of claim 2 in combination with means for directing laser energy onto a target thereby producing x-rays which are directed onto said microchannel plate.

4. The instrument of claim 2 in combination with means for directing gamma-rays onto said microchannel plate.

5. A method of increasing the sensitivity of a conventional streak camera using a photocathode for measuring photons in the ultra-violet to gamma-ray range, comprising the steps of:

removing the photocathode, and

installing a microchannel plate electron multiplier in place of the photocathode, thereby increasing the sensitivity of the camera so as to have the capability of measuring x-rays having an energy of at least 100 KeV.

6. The method of claim 5, additionally including the step of positioning a photocathode in front of adjacent to the microchannel plate, whereby the camera is sensitive to optical light as well as to high energy x-rays.