Radio-frequency accelerating cavity and circular accelerator

An RF accelerating cavity for use in a circular accelerator which accelerates a charged particle beam and accumulates accelerated electrically charged particles where necessary, said RF accelerating cavity comprising:

• an accelerating cavity unit including an acceleration electrode gap for generating an RF electric field for accelerating the charged particle beam and an acceleration core forming a magnetic path surrounding an orbit of the charged particle beam;
• and
• an inductance varying device of which magnetic member is connected parallel to said acceleration electrode gap;
• wherein inductance produced by said inductance varying device is varied in accordance with a changing pattern of a charged particle beam acceleration frequency to tune said RF accelerating cavity such that the charged particle beam acceleration frequency matches a resonant frequency of said RF accelerating cavity;
• said inductance varying device including:
• a stationary semicircular toroidal core member;
• a rotatable semicircular toroidal core member disposed rotatably on an axis commonly shared with said stationary semicircular toroidal core member with a specific gap length held between said two core members;
• and
• a turning mechanism for turning said rotatable semicircular toroidal core member;
• wherein said turning mechanism turns said rotatable semicircular toroidal core member in accordance with a changing pattern of a charged particle beam acceleration frequency to tune said RF accelerating cavity by varying inductance produced by said inductance varying device such that the charged particle beam acceleration frequency matches the resonant frequency of said RF accelerating cavity.

An RF accelerating cavity for use in a circular accelerator which accelerates a charged particle beam and accumulates accelerated electrically charged particles where necessary, said RF accelerating cavity comprising:

• an accelerating cavity unit including an acceleration electrode gap for generating an RF electric field for accelerating the charged particle beam and an acceleration core forming a magnetic path surrounding an orbit of the charged particle beam;
• and
• an inductance varying device of which magnetic member is connected parallel to said acceleration electrode gap;
• wherein inductance produced by said inductance varying device is varied in accordance with a changing pattern of a charged particle beam acceleration frequency to tune said RF accelerating cavity such that the charged particle beam acceleration frequency matches a resonant frequency of said RF accelerating cavity;
• said inductance varying device including:
• a stationary semicircular toroidal core member;
• a rotatable multipolar toroidal core member disposed rotatably on an axis commonly shared with said stationary semicircular toroidal core member with a specific gap length held between said two core members, said rotatable multipolar toroidal core member being made up of two rotatable semicircular toroidal core segments which are joined together at right angles to each other;
• and
• a turning mechanism for turning said rotatable multipolar toroidal core member;
• wherein said turning mechanism turns said rotatable multipolar semicircular toroidal core member in accordance with the changing pattern of the charged particle beam acceleration frequency to tune said RF accelerating cavity by varying inductance produced by said inductance varying device such that the charged particle beam acceleration frequency matches the resonant frequency of said RF accelerating cavity.

An RF accelerating cavity for use in a circular accelerator which accelerates a charged particle beam and accumulates accelerated electrically charged particles where necessary, said RF accelerating cavity comprising:

• an accelerating cavity unit including an acceleration electrode gap for generating an RF electric field for accelerating the charged particle beam and an acceleration core forming a magnetic path surrounding an orbit of the charged particle beam;
• and
• a fixed inductance connected parallel to said acceleration electrode gap;
• wherein said RF accelerating cavity is tuned by properly selecting the physical size of said fixed inductance such that a charged particle beam acceleration frequency matches a resonant frequency of said RF accelerating cavity;
• and
• wherein a material of said acceleration core has a μpQf-value differing from that of a magnetic material of said fixed inductance, the μpQf-value of said acceleration core being lower than the μpQf-value of said fixed inductance.

An RF accelerating cavity for use in a circular accelerator which accelerates a charged particle beam and accumulates accelerated electrically charged particles where necessary, said RF accelerating cavity comprising:

• an accelerating cavity unit including an acceleration electrode gap for generating an RF electric field for accelerating the charged particle beam and an acceleration core forming a magnetic path surrounding an orbit of the charged particle beam;
• and
• an inductance varying device of which magnetic member is connected parallel to said acceleration electrode gap;
• wherein inductance produced by said inductance varying device is varied in accordance with a changing pattern of a charged particle beam acceleration frequency to tune said RF accelerating cavity such that the charged particle beam acceleration frequency matches a resonant frequency of said RF accelerating cavity;
• said inductance varying device including:
• a cavity core;
• and
• a current power supply;
• wherein said current power supply feeds a current for producing a biasing magnetic field which is applied to said cavity core in accordance with the changing pattern of the charged particle beam acceleration frequency to vary the inductance produced by said inductance varying device such that the charged particle beam acceleration frequency matches the resonant frequency of said RF accelerating cavity.

An RF accelerating cavity for use in a circular accelerator which accelerates a charged particle beam and accumulates accelerated electrically charged particles where necessary, said RF accelerating cavity comprising:

• an accelerating cavity unit including an acceleration electrode gap for generating an RF electric field for accelerating the charged particle beam and an acceleration core forming a magnetic path surrounding an orbit of the charged particle beam;
• and
• an inductance varying device of which magnetic member is connected parallel to said acceleration electrode gap;
• wherein inductance produced by said inductance varying device is varied in accordance with a changing pattern of a charged particle beam acceleration frequency to tune said RF accelerating cavity such that the charged particle beam acceleration frequency matches a resonant frequency of said RF accelerating cavity;
• said inductance varying device including:
• a plurality of cavity cores arranged in a series;
• a plurality of current power supplies provided for said individual cavity cores;
• and
• a plurality of switches connected to said individual current power supplies;
• wherein said individual switches are controllably turned on to feed currents for producing biasing magnetic fields which are applied to said cavity cores in accordance with the changing pattern of the charged particle beam acceleration frequency to vary the inductance produced by said inductance varying device such that the charged particle beam acceleration frequency matches the resonant frequency of said RF accelerating cavity.

An RF accelerating cavity for use in a circular accelerator which accelerates a charged particle beam and accumulates accelerated electrically charged particles where necessary, said RF accelerating cavity comprising:

• an accelerating cavity unit including an acceleration electrode gap for generating an RF electric field for accelerating the charged particle beam and an acceleration core forming a magnetic path surrounding an orbit of the charged particle beam;
• and
• an inductance varying device of which magnetic member is connected parallel to said acceleration electrode gap;
• wherein inductance produced by said inductance varying device is varied in accordance with a changing pattern of a charged particle beam acceleration frequency to tune said RF accelerating cavity such that the charged particle beam acceleration frequency matches a resonant frequency of said RF accelerating cavity:
• said inductance varying device including:
• a plurality of cavity cores arranged in a series;
• and
• a switch provided at a point in a circuit between any two adjacent ones of said cavity cores;
• wherein said switch is controllably turned on in accordance with the changing pattern of the charged particle beam acceleration frequency to vary the inductance produced by said inductance varying device such that the charged particle beam acceleration frequency matches the resonant frequency of said RF accelerating cavity.

An RF accelerating cavity for use in a circular accelerator which accelerates a charged particle beam and accumulates accelerated electrically charged particles where necessary, said RF accelerating cavity comprising:

• an accelerating cavity unit including an acceleration electrode gap for generating an RF electric field for accelerating the charged particle beam and an acceleration core forming a magnetic path surrounding an orbit of the charged particle beam;
• and
• an inductance varying device of which magnetic member is connected parallel to said acceleration electrode gap;
• wherein inductance produced by said inductance varying device is varied in accordance with a changing pattern of a charged particle beam acceleration frequency to tune said RF accelerating cavity such that the charged particle beam acceleration frequency matches a resonant frequency of said RF accelerating cavity;
• wherein a material of said acceleration core has a μpQf-value differing from that of a magnetic material of said inductance varying device, the μpQf-value of said acceleration core being lower than the μpQf-value of said inductance varying device.

An RF accelerating cavity for use in a circular accelerator which accelerates a charged particle beam and accumulates accelerated electrically charged particles where necessary, said RF accelerating cavity comprising:

• an accelerating cavity unit including an acceleration electrode gap for generating an RF electric field for accelerating the charged particle beam and an acceleration core forming a magnetic path surrounding an orbit of the charged particle beam;
• an inductance connected parallel to said acceleration electrode gap;
• and
• an electrode plate inserted in the acceleration electrode gap for dividing a capacitance into a plurality of capacitances and an inductance varying device connected parallel to at least one of the plurality of capacitances.