Titanium pump power

Titanium pump power is high resistance power supply, its no-load output voltage in the 3~7KV rooms, but a large load current, the output voltage drops to about 400V.

  General sputtering ion pump to use 5KV voltage rectifier. titanium alloy pump can flow through the anode and cathode of the discharge current reflected in space vacuum pumping.

  Sputtering ion pump Iion discharge current at rated voltage and the strength of the magnetic field (mA) and pressure P (Torr) have a certain curve.

  So the ion pump power can be reflected by the size of the pressure. Pump power display panel are,titanium pump output DC high voltage and discharge current.

Properties of titanium pump

1)10-8 PA pressure limit

(2) the pumping speed,
titanium pump pumping speed and the anode voltage and magnetic field intensity, magnetic field strength when the pumping speed is high, the anode voltage corresponding to the best pumping speed is high.

  Commonly used titanium pump pumping speed of 25 L / s, 5 liters / sec. Require large pumping speed for the occasion, the basic structural unit can be used in parallel manner to make the pumping speed 50 L / s, 100 liters / sec etc..

(3) start pressure, 10-2 pa
(4) life,

•  cathode depletion of life

Plate due to sputtering cathode penetrating and the pump can not be used.

•  anodic stripping life

Anodic Deposition of titanium film thickness is too large will have peeled off, resulting in irregular titanium alloy pump pressure is intense change, the pump can not be used.

•  anode sucking the life

The anode of adsorbed and dissolved a lot of helium, hydrogen, when the saturated adsorption gas when the pump can not.

  Under normal circumstances, life of up to tens of thousands of hours of sputtering ion pump.

Titanium pump gas removal mechanism

1) on the activity of gas exhausting

Chemical adsorption excluded depends mainly on the deposited on the anode cylinder wall titanium membrane for N2, O2, CO and CO2 gases.


2) of the hydrogen pumping

The hydrogen titanium pumps chemical adsorption, diffusion, absorption, or dissolution.


3) on the inert gas exhausting

Exclusion of inert gases, mainly by ion buried, by inert gas ion bombardment ionization of the cathode, the following three conditions,

• Ion directly into the cathode, anode plate or into the cathode edge on the opposite side of the titanium  deposition in.

• Oblique ion cut into the surface of the cathode, with ion and titanium was blown off and deposited on the cathode plates or other places around.

• Ion did not enter the plate, but receive electronic and composite for neutral atoms from.the cathode, and then reflected to the inner surface of the titanium anode film.

The secondary electrons of titanium plate

Ion bombardment of titanium plates can be hit two times, electronic, electromagnetic field into the rotating electron clouds two times by electronic, electronic supplement lost.

  Each of the gas molecules are ionized at the same time, at least let a electronic, these electronic also enters the rotating electron cloud, they and the two electronic together compensation electron loss went to the anode and, thus can continue to maintain Pan Ning discharge.

Inspiratory capacity of titanium film

Sputtered titanium  atoms deposited on the inner wall, the anode and cathode plate pumping ability, forming a titanium film fresh maintaining titanium pump. Sputtering ion with the incident ion energy, mass and incident angle is different, high energy, sputtering ion mass is big. The oblique better effect than vertical bombardment.

  In order to ensure that the suction capacity of titanium film on the anode cylinder, must ensure enough sputtering rate, that is required to have enough voltage, to ensure that the ion energy bombarding get enough.

Ion bombardment of titanium plate

Gas molecules and electron impact ionization and is rotating, gas ions under the action of the electric field, fly and the bombardment of the cathode titanium plate.

Two effects of titanium plates ion bombardment,
1, the formation of sputtered titanium pump, titanium film.
2, hit two times electron.

Pan Ning discharge,titanium pump

When the anode voltage is high, in order to avoid electronic fall to the anode, must add a strong axial magnetic field. In the axial direction, central section movement when the electronic anode cylinder, accelerated by the effect of electric field force, the electron velocity is larger and larger, across the central section, the electric force impede the electron do decelerated motion, close to the cathode plate Vz decay to zero, the electron acceleration by electric field force and the effect of re the reverse acceleration movement, and started to decelerate over center section, repeat the above exercise so don't stop.

  Electrons in the anode tube in after a long journey to fall on the anode. A large number of electronic magnetic field constraints to wheel line form close to the anode cylinder rotation, the formation of a layer of electron cloud. The rotation frequency rotating electron cloud is about 100MHz, the electron density of up to 1010 (A / cm 3) order. The phenomenon known as the Pan Ning discharge.