Superconducting cyclotron neutron source for therapy

• US 3,925,676 A
• Filed: 07/31/1974
• Issued: 12/09/1975
• Est. Priority Date: 07/31/1974
• Status: Expired due to Term

• Current Assignee: Clifford B. Bigham, Harvey R. Schneider
• Original Assignee: Clifford B. Bigham, Harvey R. Schneider
• Inventors: Bigham, Clifford B., Schneider, Harvey R.
• Primary Examiner(s): Willis, Davis L.
• Application Number:
  US05/493,415
• Time in Patent Office: 496 Days
• Field of Search: 250/499-502 313/61R,61S,62
• US Class Current: 376/112
• CPC Class Codes: A61N 2005/109 Neutrons
• CPC Class Codes: A61N 5/10 X-ray therapy; Gamma-ray therapy; Particle-irradiation therapy A61N5/01 takes precedence
• CPC Class Codes: H05H 13/00 Magnetic resonance accelerators; Cyclotrons strophotrons, turbine tubes H01J25/62
• CPC Class Codes: H05H 3/06 Generating neutron beams targets for producing nuclear reactions H05H6/00; neutron sources G21G4/02

Abstract

A neutron source for medical therapy purposes comprising a cyclotron comprising an iron metal housing acting as a magnetic yoke, magnetic shield, radiation shield, and vacuum vessel, a pair of superconducting coils mounted in a cavity in the housing said coils being cooled to superconducting temperatures by passage of a refrigerant fluid therethrough and connected to an electrical energy source such that a high current flows in the coils producing an intense magnetic field inwardly between the coils, an ion orbiting region defined by pairs of sectoral-shaped RF electrode structures energized at an RF frequency and focussing flutter poles mounted in the intense magnetic field between coils, a source of ions positioned centrally of the ion orbiting region to provide a stream of ions that will be orbited in the orbit region; an ion target positioned internally of said iron housing at an outer position in the orbit region such that orbiting ions strike the target and produce neutrons; a channel formed in the iron housing from the target to the exterior for passage of the beam of neutrons formed at the target, said channel acting as a beam collimator; and a mounting structure for movably mounting the cyclotron and target such that the neutron beam produced can be employed at more than one position.

Claims

1. A neutron source for medical therapy purposes comprising:

a. a cyclotron comprising an iron metal housing acting as a magnetic yoke, magnetic shield, radiation shield, and vacuum vessel, a pair of superconducting coils mounted in a cavity in the housing said coils being cooled to superconducting temperatures by passage of a refrigerant fluid therethrough and connected to an electrical energy source such that a high current flows in the coils producing an intense magnetic field inwardly between the coils, an ion orbiting region defined by pairs of sectoral-shaped RF electrode structures energized at an Rf frequency and focussing flutter poles mounted in the intense magnetic field between coils, a source of ions positioned centrally of the ion orbiting region to provide a stream of ions that will be orbited in the orbit region;

b. an ion target positioned internally of said iron housing at an outer position in the orbit region such that orbiting ions strike the target and produce neutrons;

c. a channel formed in the iron housing from the target to the exterior for passage of the beam of neutrons formed at the target, said channel acting as a beam collimator; and

d. a mounting structure for movably mounting the cyclotron and target such that the neutron beam produced can be employed at more than one position.

2. A neutron source as in claim 1 wherein the ions orbited in the cyclotron are deuterons and the target is a thick beryllium metal layer.

3. A neutron source as in claim 1 wherein the ions orbited in the cyclotron are deuterons and the target is a thick lithium metal layer.

4. A neutron source as in claim 1 wherein the mounting structure is a gantry allowing movement of the cyclotron and thus the neutron beam in an isocentric path.

5. A neutron source as in claim 1 wherein the flutter poles are four in number and are formed as spiral-edged sectoral raised portions of the iron housing structure defining valleys between with the said RF electrode structures being positioned in the valley regions.

6. A neutron source as in claim 1 wherein the refrigerant fluid is supercritical helium at a temperature of 4.2K.