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| Effusion Cells & Valved Crackers |
Welcome to the Riber's selection guide for effusion cells and valved crackers.
More than any other component, effusion cells and
valved crackers have a direct impact on the quality of materials grown by
MBE (i.e. morphology, purity, composition, uniformity, etc.). With over
7000 MBE sources in the field, Riber has the largest installed base of any
company. Our experience in high-quality components and years of close cooperation
with major research and production groups has brought Riber to the forefront
of MBE source technology.
Product Range > Riber offers a comprehensive
range of effusion cells and crackers for mounting on Riber and other commercial
MBE systems. Riber effusion cells and crackers provide pure, stable and
reproducible beam fluxes of elemental species. Different types of effusion
cells and valved crackers are available for specific source materials.
| Construction Standards
> The development and manufacturing of effusion cells and
valved crackers demand stringent fabrication procedures. The necessary
high quality is obtained only by careful design of all constituent
elements and rigorous selection of construction materials. Effusion
cells and valved crackers include adequate materials to ensure the
purity of the final epilayers. Only refractory materials with very
low vapor pressures are used for parts which may reach temperatures
higher than 150°C. All dismountable flanges are vacuum-sealed with
silver-coated gaskets in order to avoid any reaction with arsenic.
Riber UHV flanges are compatible with standard Conflat® dimensions
(see table >). |
|
| Conflat (O.D.) |
RIBER (I.D.) |
| 2.75" |
35 CF |
| 4.5" |
63 CF |
| 6.0" |
100 CF |
| 8.0" |
150 CF |
| 10.0" |
200 CF |
|
Riber effusion cells and valved crackers are assembled
and conditioned in class-100 clean room to avoid impurity particles to create
stray residues during UHV thermal cleaning. The crucible surface is guaranteed
free of any contamiation. Appropriate outgassing is performed on each part
separately before assembly, and on the complete cell after assembly (with
and without the crucible). These treatment procedures have been established
after a complete and detailed analysis of their effect on growth results
in our applications laboratory. Effusion cells and valved crackers are packaged
under nitrogen in stainless steel containers for cleanliness and safety
during storage and transportation.
Base Features > Riber effusion cells and valved
crackers are compatible with any commercial or homemade MBE system (if in
doubt, ask!). Each effusion cell includes an oven (filament + thermocouple)
and fully degassed thick PBN crucible,
surrounded by adequate tantalum shielding for use in proximity of
a cryoshroud. PBN crucibles are designed to provide a very stable
flux during charge depletion. The heating filament is made of high
purity tantalum foil. The contact thermocouple is located at the bottom
of the crucible. Electrical insulators are made of PBN. The source
mounting flange houses power and thermocouple feedthroughs.
Power supply and temperature control are implemented
by the use of microprocessor-based controllers (available as options).
These self-contained units provide power supply, PID control with
auto tune capability and plug-in RS422-RS485 computer interface capability. |
|
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Specific Features > The following should
be specified when ordering.
 Effusion
cell crucible capacity (cc) according to Riber systems
|
MBE 32 |
Compact 21 |
Epineat |
MBE 49 |
| Ga, In |
35 |
60 / 80 |
125 / 150 |
600 / 700 |
| Autres (e.g. Al) |
35 |
60 / 80 |
125 / 150 |
350 |
| Dopants |
13 |
5 |
25 |
70 |
Thermocouple,
type C (W/Re 5/26%) or type K (Cr/Al).
 Mounting
flange O.D., tube I.D. and in-vacuum dimensions.
SELECTION TABLE
Select your MBE source according to your application and your MBE system.
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