VCCS 100-420 Sb valved corrosive material cracker source on DN100 CF (O.D. 6") mounting flange (with adapter flange VADP 100-63-K)
The Valved Corrosive Material Cracker Source VCCS is designed for controlled injection of radicals of antimony, tellurium, magnesium or other corrosive materials in standard MBE applications. Parts directly exposed to the evaporant like crucible, valve mechanism, injector tube and cracker are solely made from PBN to minimize corrosion of the cell.
Additional equipment for the VCCS (motorized valve control unit MVCU with temperature controllers and power supplies)
Three independent heater circuits allow precise and flexible adjustment of the temperatures in each part of the cell in order to provide sufficient material vapor, avoid condensation within the valve or injector tube and ensure maximum cracking efficiency, each according to the requirements of the particular evaporant. A schematic illustration of the sequence of the different heater stages is shown in the figure on the right.
Schematic illustration of the VCCS all PBN assembly
The main purpose of the VCCS in MBE applications is enhanced flux control and cracking of materials whose vapor is highly corrosive to metallic surfaces. The VCCS was originally designed as a source for an antimony radical (Sb2) molecular beam as group V material in standard III-V MBE. It uses the well-established concept of sublimation of elemental Sbn followed by a step of thermal dissociation in a cracker stage to produce a Sb2 molecular beam. The VCCS all PBN construction of the inner parts, in particular the valve mechanism, in combination with the flexibility provided by three independent heater circuits allows applying this concept to other materials like Te, Mg or Se.
The valve mechanism and hence the beam flux can be regulated either manually or remotely by a servo motor drive (MVCU) with a 0-10 V analogue input signal.
A large crucible capacity of 420 cm³, fast and precise flux control and easy handling for maintenance and crucible refill make the VCCS an ideal source for smaller production MBE systems as well as for higher throughput research MBE systems.
|Filament type||3 separate heater-circuits (cell / valve / cracker)|
|Thermocouple||3 W5%Re/W26%Re (type C) thermocouples (cell / valve / cracker)|
|Operating temperature (for Sb-sublimation)
||cell crucible: 550-650°C; valve: 600-700°C; cracker: 650-1200°C|
|Outgassing temperature||cell crucible: 800°C; valve: 900°C; cracker: 1300°C|
|Cooling||integrated water cooling shrouds|
||integrated all PBN valve mechanism / cell temperature|
|Valve control||stepper motor drive with control unit MVCU|
|Schematic drawing of the Sb-Valved Corrosive Material Cracker Source VCCS
VCCS 100-420 with VADP adapter)
For general information on CF mounting flanges see Flange and Gasket dimensions.
|[cm3]||[mm] / [mm]||[W] / [A]||Product code|
|VCCS||100* -||420**-||LxxxD38||cell : 315 / 9
valve : 400 / 8
cracker : 455 / 13
|cell : PS 60-12.5-C
valve : PS 60-12.5-C
cracker : PS 40-19-C
|*||other mounting flange diameters feasible in combination with VADP adapter flanges (on request)|
|**||other capacities on request|
|***||specify UHV length L with order|
e.g. VCCS 100-420-L305D38
is a valved corrosive material cracker source on DN100 CF flange with 420cm³ crucible and UHV-length 305mm.