Radiotherapy apparatus and radiation irradiating method

1. A radiotherapy apparatus comprising:

an acceleration unit configured to generate a charged particle beam;

a target configured to generate x-ray radiation when the charged particle beam is irradiated to said target;

a sensor configured to measure an electric current flowing through said target;

a dosimeter configured to measure a dose of the x-ray radiation; and

a control unit configured to control said acceleration unit based on the measured electric current and the measured dose,

wherein said control unit controls said acceleration unit based on a quotient obtained when the measured dose or a dose per a predetermined time is divided by the measured electric current.

2. The radiotherapy apparatus according to claim 1 , wherein said control unit performs a feedback control on said acceleration unit such that the quotient is constant.

3. The radiotherapy apparatus according to claim 2 , wherein said acceleration unit comprises:

an electron gun configured to emit charged particles;

an accelerating tube power supply configured to generate high frequency power;

an accelerating tube configured to accelerate the charged particles by using the high frequency power to generate the charged particle beam,

said control unit controls said accelerating tube power supply such that the quotient is constant.

4. The radiotherapy apparatus according to claim 3 , wherein said acceleration unit further comprises:

an electron gun power supply configured to generate charged particle emission power,

said electron gun emits the charged particles by using the charged particle emission power, and

said control unit controls said electron gun power supply such that an emission amount of the charged particles is constant.

5. The radiotherapy apparatus according to claim 2 , wherein said acceleration unit comprises:

an electric gun power supply configured to generate charged particle emission power;

an electron gun configured to emit charged particles by using the charged particle emission power; and

an accelerating tube configured to accelerate the charged particles to generate the charged particle beam,

wherein said control unit controls said electric gun power supply such that the quotient is constant.

6. The radiotherapy apparatus according to claim 5 , wherein said electron gun power supply has a function to generate cathode heat power, and

said electron gun comprises a cathode configured to emit the charged particles by the cathode heat power.

7. The radiotherapy apparatus according to claim 5 , wherein said electron gun power supply has a function to generate a grid voltage, and

said electron gun comprises:

a cathode configured to emit the charged particles; and

a grid configured to accelerate the charged particles by using the grid voltage.

8. The radiotherapy apparatus according to claim 2 , wherein said acceleration unit further comprises an accelerating tube power supply configured to generate high frequency power,

said accelerating tube accelerates the charged particles by using the high frequency power to generate the charged particle beam, and

said control unit controls said accelerating tube power supply such that the high frequency power is constant.

9. The radiotherapy apparatus according to claim 8 , wherein said accelerating tube power supply comprises a de-Qing circuit configured to makes a voltage of the high frequency power constant.

10. A radiation irradiating method comprising:

measuring electric current flowing through a target which irradiates x-ray radiation when a charged particle beam generated by an acceleration unit is irradiated;

measuring a dose of the x-ray radiation; and

controlling said acceleration unit based on the measured electric current and the measured dose,

wherein said controlling comprises:

controlling said acceleration unit based on a quotient obtained when the measured dose or a dose per a predetermined time is divided by the measured electric current.

11. The radiation irradiating method according to claim 10 , wherein said controlling comprises:

performing a feedback control on said acceleration unit such that the quotient is constant.

12. The radiation irradiating method according to claim 11 , further comprising:

emitting charged particles from an electric gun;

generating high frequency power by an accelerating tube power supply; and

accelerating the charged particles by using the high frequency power to generate the charged particle beam,

wherein said controlling comprises:

controlling said accelerating tube power supply such that the quotient is constant.

13. The radiation irradiating method according to claim 12 , further comprising:

generating charged particle emission power by an electron gun power supply,

wherein said emitting comprises:

emitting the charged particles by using the charged particle emission power, and

said controlling comprises:

controlling said electron gun power supply such that an emission amount of the charged particles is constant.

14. The radiation irradiating method according to claim 11 , further comprising:

generating charged particle emission power from an electric gun power supply;

emitting the charged particles by using the charged particle emission power; and

accelerating the charged particles to generate the charged particle beam,

wherein said controlling comprises:

controlling said electric gun power supply such that the quotient is constant.

15. The radiation irradiating method according to claim 14 , further comprising:

generating high frequency power from an accelerating tube power supply,

wherein said accelerating the charged particles comprises:

accelerating the charged particles by using the high frequency power to generate the charged particle beam, and

said controlling comprises:

controlling said accelerating tube power supply such that the high frequency power is constant.

16. The radiation irradiating method according to claim 14 , wherein said emitting comprises:

generating cathode heat power from said electron gun power supply; and

emitting the charged particles from a cathode of said electric gun with the cathode heat power.

17. The radiation irradiating method according to claim 14 , wherein said accelerating the charged particles comprises:

generating a grid voltage; and

accelerating the charged particles by using the grid voltage.