The manufacturing principle and the basic working principle of titanium pump

Vacuum is the essence of molecules with low concentration of gas space. Therefore, as long as the gas molecule concentration can reduce the space vacuum, without actually exhaust process.

  titanium pump is based on the principle of manufacture.

  By heating, ionization methods make titanium atomic and space of gas molecules to a series of complex physical and chemical reaction, the gas molecule with titanium atoms deposited together, so as to achieve the purpose of reducing the space gas molecule concentration.

  This is the basic principle of titanium alloy pump. This and the principle of compression pump (to be gas from one party to another party to obtain the compression vacuum) different.

Titanium pump and vacuum pump

Titanium pump is a vacuum pump, but it is different from the ordinary compression type pump.

  titanium  pump has no rotary mechanism, also do not use the vacuum pump oil, it uses the way of removing gas trapping of gas molecules, can get high vacuum cleaner, which improve the quality of the light source has a great help.


  However, titanium pump special degassing principle and special structure to make it with the ordinary vacuum pump operation, maintenance and repair are different.

Sputtering ion pump fault

Titanium pump is a non polluting and ultra high vacuum pump, can be divided into titanium sublimation pump, titanium pump evaporator  several.

  Sputtering ion pump generates Pan Ning discharge in high voltage and high magnetic field, gas molecules adsorbed to the vacuum container.

  Due to aging equipment or improper operation and other reasons, sputtering ion pump will fault.

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.

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.

Titanium pump working principle

The motion of the electron in the titanium pump anode tube in axial velocity component, Vz and radial velocity Vr, because Vr and axial magnetic field Bz perpendicular, electron by the Lorentz force F=eVr´ Bz effect, so the electrons to the anode tube in addition to the action of electric field force is axial symmetry, but also by the Lorentz force Bz, the electron motion into linear motion and axial cross section on thewheel rolling line movement. 

   In cross section of electricity Sub wheel rolling line moving radius size is a function of the electron velocity and magnetic fieldstrength, the larger the electronic speed (the anode voltage is higher), round the ring rolling line larger; magnetic field stronger, wheel rolling line of the circle is smaller.

The structure of the titanium pump

There are two kinds of structure: Sunrui titanium pump diode pump and three pole pump. Diode, titanium pump, it generated by permanent magnet strength is 0.1 ~ 0.3 tesla's axial magnetic field, the anode is composed of a number of 0.1 ~ 0.3 mm thick, 12 ~ 40 mm diameter stainless steel thin wall cylinder, the anode at both ends for 1 ~ 3 mm thick titanium cathode, plus 3 ~ 7 kv voltage between the poles, produce strong electric fields. Electric field will electronic pull between two cathode to anode, in to the center line of the anode movement, faster and faster, with a cross the center line, from the other side of the cathode repulsion, began to slow motion, near the cathode, reverse speed to zero. Electronic repeat the exercise for many times, after a long time to fall to the anode. The axial magnetic field have made electronic circular motion, direct and rapid fly to prevent electronic anode. Electromagnetic field the overall effect of the electronics in the form of a helix movement close to the anode, forming a layer of electron cloud around the anode, increases the chances of the electrons collide with the residual gas ionization. Electrons from one collide with the residual gas in a vacuum to the next by the average distance between collision is called the mean free path. When 10-6 Tuo vacuum mean free distance is about 285 meters. And the average free path in titanium pump greatly shortened. Three pole titanium pump, it is in front of the pump diode titanium cathode increased pump wall, form a third electrode, pump wall and anodic potential, titanium ion sputtering atom to the walls of the pump where the oblique sputtering out more than a diode pump titanium atoms.

Gas molecules and high-speed movement of electron impact ionization, form positive ions and one or more electrons, the electronic controlled electromagnetic field into the rotating electron cloud, when it again with the gas molecular collision, ionization again and produce new electronic, the electron, called numerous secondary electron flow. Positive ions in the role of the electromagnetic field to the cathode accelerated motion, and the bombarding cathode sputtering titanium plate titanium atoms on the surface of the cathode and secondary electron. Gas ion impact of cathode, and from the cathode surface to release one or more atoms process known as sputtering. Sputtering of titanium atoms deposited on the inner wall of the anode and the cathode plate, forming new titanium membrane, maintain titanium pump suction ability. An ion bombardment of titanium and titanium plate can splash of atoms called sputtering coefficient. Sputtering coefficient associated with ion energy, quality and incident Angle. Must maintain enough voltage of Yin and Yang to keep on titanium anode tube membrane adsorption ability. Ion bombardment titanium target to produce secondary electron, and under the action of electromagnetic field, high speed movement into the electron cloud, with numerous flow secondary electron supplement because of absorbed by anode electronic continuously maintain penning discharge.