CN104202901A - Electromagnetic coil of microwave electron cyclotron resonance plasma source - Google Patents

Abstract

The invention discloses an electromagnetic coil of a microwave electron cyclotron resonance plasma source. The electromagnetic coil comprises a hollow electromagnetic coil, and is characterized in that an external magnetic yoke is coated outside the electromagnetic coil; outer-end magnetic yokes are coated at the both ends of the coil; the external magnetic yoke is connected with the outer-end magnetic yokes to completely cover the whole electromagnetic coil; an annular bulge is arranged at the inner side close to a central port, of each of the outer-end magnetic yokes, and used for enhancing the gradient of a magnetic induction intensity in the coil. The electromagnetic coil disclosed by the invention is capable of enhancing the magnetic induction intensity therein, thus magnetic field distribution is more uniform, and the external electromagnetic radiation of the electromagnetic coil is reduced.

Description

A kind of microwave electron cyclotron resonance plasma source solenoid

Technical field

The present invention relates to a kind of solenoid, particularly a kind of microwave electron cyclotron resonance plasma source solenoid that has yoke.

Background technology

Microwave electron cyclotron resonance plasma is widely used in material surface and processes, the fields such as metal surface modification, by at the additional solenoid of microwave electron cyclotron resonance plasma, generate an electromagnetic field, and in electron cyclotron resonace chamber, cause electron cyclotron resonace to produce a large amount of plasmas, for the beam-plasma processing operation of some material.At present, the solenoid that is used for producing magnetic field is comprised of the water-cooled coil of copper pipe coiling or the coil of solid conductor coiling, uncontrollable and the skewness of magnetic field space that this class solenoid produces, cause plasma process precision not high, the external electromagnetic radiation of solenoid is simultaneously larger, easily human body and external equipment is caused damage.

Summary of the invention

For addressing the above problem, the invention provides a kind of microwave electron cyclotron resonance plasma source solenoid that has yoke, by solenoid outside and outer end, yoke being set, change coil internal magnetic field and distribute, intensifier coil intrinsic inductance, reduces the external electromagnetic radiation of coil.

Technical solution of the present invention is:

A kind of microwave electron cyclotron resonance plasma source solenoid, include hollow electromagnetic coil, it is characterized in that: in solenoid outside, be coated with outside yoke, at coil two ends, be coated with outer end yoke, outside yoke is connected with outer end yoke, and whole solenoid is covered completely.

Described microwave electron cyclotron resonance plasma source solenoid is provided with annular protrusion in outer end yoke near inner side, place, the middle pit of the stomach, for intensifier coil internal magnetic field intensity gradient.

Outside yoke and the outer end yoke of described microwave electron cyclotron resonance plasma source solenoid are soft magnetic material.

Outside yoke and the outer end yoke of described microwave electron cyclotron resonance plasma source solenoid are assemblied to form by polylith yoke assembly.

The invention has the beneficial effects as follows:

(i) by outside yoke and outer end yoke are set, can make solenoid internal magnetic field distribute more even, magnetic field intensity further strengthens, particularly in outer end yoke, near inner side, place, the middle pit of the stomach, annular protrusion is set, magnetic field in solenoid can be limited in yoke apart from very near space, effectively improve magnetic flux density gradient, the energy of the output of plasma beam is got a promotion.

(ii) outer end yoke and outside yoke the magnetic circuit reluctance that can effectively reduce solenoid is set, significantly reduce excitatory power, thereby save more electric energy and cooling water.

(iii) owing to there being the magnetic field of yoke coil to be limited in yoke apart from very near space; for the instrument and equipment or the suffered electromagnetic radiation of personnel that approach solenoid, become very little; can effectively protect operating personnel's safety; the instrument and equipment that also can make nearby to use is avoided the impact of electromagnetic field, extension device useful life.

Accompanying drawing explanation

Fig. 1 is the schematic perspective view of microwave electron cyclotron resonance plasma source solenoid.

Fig. 2 is without magnetic flux density distribution map on yoke solenoid axis.

Fig. 3 is for there being magnetic flux density distribution map on yoke solenoid axis.

Fig. 4 is the magnetic flux density distribution map without yoke plasma end.

Fig. 5 is the magnetic flux density distribution map that has yoke plasma end.

Fig. 6 is the magnetic flux density distribution map without yoke plasma sidepiece.

Fig. 7 is the magnetic flux density distribution map that has yoke plasma sidepiece.

Embodiment

Embodiment produces the magnetostatic field of 87.5 milli teslas with microwave electron cyclotron resonance plasma source, plasma microwave injected frequency is that 2.45Ghz is example, and the present invention is further described.

As shown in Figure 1, microwave electron cyclotron resonance plasma source solenoid includes hollow electromagnetic coil 1, and solenoid outside is coated with outside yoke 2, at coil two ends, is coated with outer end yoke 3, outside yoke is connected with outer end yoke, and this solenoid is covered completely.Solenoid is socketed on plasma resonance chamber 5.By suitably adjust the spatial distribution in magnetic field make electron gyro-frequency along arc chamber axially on a certain position consistent with the circular frequency of microwave, generation covibration.Disperse along axis in magnetic field, by means of the gradient of divergent magnetic field, the plasma producing can be transported in operating room, for use in arc chamber.In outer end yoke, near inner side, place, the middle pit of the stomach, can be provided with annular protrusion 4, for control coil changes of magnetic field, intensifier coil internal magnetic field intensity.

Table 1 has listed without yoke solenoid and has had the contrast of maximum magnetic induction on yoke solenoid axis and the excitatory power contrast of excitation apparatus under same magnetic field intensity.By table 1 and Fig. 2, Fig. 3, can be found out have yoke solenoid internal magnetic field to distribute more even, on axis, maximum magnetic induction is larger.Under same magnetic field intensity, there is yoke solenoid to have obvious reduction than the excitatory power without yoke coil, decrease by 36%, thereby save a large amount of electric energy and cooling water.

On table 1 axis, maximum magnetic induction is to excitatory power contrast under same magnetic field intensity when

?	Without yoke	There is yoke
			(tesla)	0.1005	0.1063
Excitatory power (watt)	437.769	280.172

Table 2 and table 3 have been enumerated respectively the magnetic flux density contrast situation of plasma end and sidepiece.No matter from table 2, table 3 and Fig. 4, Fig. 5, Fig. 6, Fig. 7, can find out there is yoke coil than the external magnetic radiation without yoke coil, be in end or sidepiece, has very significantly and decline, thereby reduced the radiation to external equipment and human body.

The magnetic flux density of table 2 plasma end distributes and contrasts

The magnetic flux density of table 3 plasma sidepiece distributes and contrasts

Axis, table 4 magnetic field place's magnetic flux density and the contrast of magnetic flux density gradient change rate

Table 4 has been enumerated and in solenoid outer end yoke, near inner side, place, the middle pit of the stomach, has been provided with annular protrusion and contrasts with axis, magnetic field place's magnetic flux density and magnetic flux density gradient change rate that solenoid does not arrange annular protrusion.As can be seen from the table, in solenoid outer end yoke, near inner side, place, the middle pit of the stomach, be provided with annular protrusion, little to coil intrinsic inductance distribution influence, but (magnetic flux density gradient calculation formula is: [magnetic flux density maximum-magnetic flux density minimum value]/magnetic flux density maximum) can significantly to increase coil intrinsic inductance gradient, the energy of the output of plasma beam is further promoted, thereby improve the precision of plasma process.

In application, generally use soft magnetic material to make outside yoke and the outer end yoke of solenoid, and the outside yoke of solenoid and outer end yoke can be assemblied to form by polylith yoke assembly.

Claims (4)

1. a microwave electron cyclotron resonance plasma source solenoid, include hollow electromagnetic coil, it is characterized in that: in solenoid outside, be coated with outside yoke, at coil two ends, be coated with outer end yoke, outside yoke is connected with outer end yoke, and whole solenoid is covered completely.

2. microwave electron cyclotron resonance plasma according to claim 1 source solenoid, is characterized in that: in outer end yoke, near inner side, place, the middle pit of the stomach, be provided with annular protrusion, for intensifier coil intrinsic inductance gradient.

3. microwave electron cyclotron resonance plasma according to claim 1 and 2 source solenoid, is characterized in that: described outside yoke and outer end yoke are soft magnetic material.

4. microwave electron cyclotron resonance plasma according to claim 1 and 2 source solenoid, is characterized in that: described outside yoke and outer end yoke are assemblied to form by polylith yoke assembly.