MBE Components, Valved Thermal Cracker Cell VTCC


Valved Thermal Cracker Cell


TCC 40-130-54-KS
VTCC 40-130-54-KS with integrated cooling shroud and shutter on DN40CF (O.D. 2.75") flange
  • Full PBN solution for corrosive materials like Te, Sb, Se, As, Mg

  • DN40CF (O.D. 2.75" ) mounting flange compatible with all MBE systems

  • Thermal cracking up to 1300°C 

  • 130 cm3 PBN reservoir 

  • Excellent thermal isolation between low temperature reservoir and hot cracking zone

  • Integrated water cooling for cracker stage

  • Integrated rotary shutter (optional)


The Valved Thermal Cracker Cell VTCC is a full PBN valved cell with a water cooled cracker stage. The compact design of the cell allows its implementation on the space-saving DN40CF (O.D. 2.75") flange.

It features a crucible size of 130 cm3 which is sufficient for most R&D applications.

The reservoir heater of the VTCC is designed to perform fast and precise ramps in the temperature range from 100°C  to 650°C.

Three independent heating zones for reservoir, valve and cracker allow flexible adjustment of the cell operating conditions.

This, in combination with the full PBN construction of the valve, reservoir and cracker, enables a wide variety of the VTCC applications with the numerous high vapor pressure evaporation materials.

The crucible and cracker zones are shrouded by water cooling, minimizing the thermal load on the chamber.
VTCC zones

 VTCC zones

click to enlarge image
VTCC characteristics: valve position versus Te flux over time

The figure on the left shows the example of the valve calibration, performed with Te. The valve demonstrates vide dynamic range, allowing precise flux adjustments in the % range of the maximal material flux.

The flux is reduced by about 5000 times when the PBN valve is closed. The VTCC may be equipped with the optional integrated shutter, with can be used to reduce the material flux even further.

The VTCC has excellent thermal insulation between the low temperature reservoir and the hot cracking stage



A source concept like this is used for high vapor pressure materials, which form atom clusters. Typical evaporation elements are As, Se, Sb, Te, Mg.

Technical data

Port to chamber DN40CF (2.75” O.D.)
In-vacuum diameter 36 mm
In-vacuum length
287 mm
Bakeout temperature 200°C
Shutter opening angle 90° ccw
Cooling water flow 30-90 l/h
Weight 15 kg
Maximum chamber pressure 10-5 mbar
Crucible capacity
130 cm³
Heater type
tantalum wire filament
Cooling integrated water cooling shroud
Operating temperature
100°C - 650°C
Maximum temperature
NiCr/NiAl (type K)
Injector tube
Heater type tantalum wire filament
Cooling none
Operating temperature 200°C - 750°C
Thermocouple W5%Re/W26%Re (type C)
Heater type
tantalum wire filament
integrated water cooling shroud
Operating temperature 300°C - 1200°C
Maximum temperature 1300°C
W5%Re/W26%Re (type C)
Cracking insert PBN



The crucible material suitable for most evaporants is PBN. Please refer to the Selection Guide or inquire for detailed recommendations. For information on crucibles see Crucibles.



Schematic drawing VTCC Schematic drawing of the  Valved Thermal Cracker Cell VTCC

(drawing shows
VTCC 40-130-54-KS)


Specific data

For general information on CF mounting flanges see Flange and Gasket dimensions.


[cm³] [mm] [mm] / [mm] [W] / [A] Product code Product code
TCC 40 - 130 - 54 - K S- L287D36 130 / 8 2x PS 30-10 ¹ PBN 130-54
* rotary shutter possible on same flange      ¹ Power supplies for reservoir and cracker heater.
For optional pipe heater a third power supply is needed.
** PBN standard


Product code:
e.g. VTCC 40-130-54-KS-L287D36

is a Valved Thermal Cracker Cell on DN40CF-flange for an 130 cm³ crucible (lip Ø 54 mm), with integrated water cooling shroud, shutter, PBN crucible, in-vacuum length 287 mm and outer diameter 36 mm.