BARS apparatus

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Template:Short description

File:BARS4.svg
Schematic of a BARS system.
File:Bars3.jpg
Pressure chamber.
File:Bars2.jpg
Two BARS devices, one open for loading or unloading and the other closed.

BARS (or "split sphere", transliteration from Template:Langx abbreviation of Template:Langx, (bespressovaya apparatura vysokogo davleniya «razreznaya sfera»), "press-free high-pressure setup «split sphere»") a high-pressure high-temperature apparatus usually used for growing or processing minerals, especially diamond and boron nitride.[1] Typical pressures and temperatures achievable with BARS are Script error: No such module "convert". and Script error: No such module "convert"..[2][1]

The BARS technology was invented around 1989–1991 by the scientists from the Institute of Geology and Geophysics of the Siberian Branch of the Academy of Sciences of the USSR.[2] In the center of the device, there is a ceramic cylindrical reaction cell of about 2 cm3 in size. The cell is placed into a cubic-shaped pressure-transmitting material, which is pressed by elements made from cemented carbide (VK10 hard alloy).[3] The outer octahedral cavity is pressed by 8 steel sectors. After mounting, the whole assembly is locked in a disc-type barrel with a diameter ~1 meter. The barrel is filled with oil, which pressurizes upon heating; the oil pressure is transferred to the central cell. The central cell is heated up by a coaxial graphite heater. Temperature is measured with a thermocouple. The exterior size is 2.2 х 1.0 х 1.2 meters. Weight of the sphere is Script error: No such module "convert".. Claimed energy consumption is in between 1.5 - 2 kWh.[4]

The growth rate for Script error: No such module "convert". type Ib (yellow, nitrogen-rich) crystals using Fe–Ni catalyst reaches as high as ~20 mg/h towards the end of 100 h growth cycle, i.e. crystals of Script error: No such module "convert". to Script error: No such module "convert". can be grown in less than 100 h.[5]

See also

<templatestyles src="Div col/styles.css"/>

References

<templatestyles src="Reflist/styles.css" />

  1. a b Script error: No such module "citation/CS1".
  2. a b Script error: No such module "Citation/CS1".
  3. Script error: No such module "Citation/CS1".
  4. Script error: No such module "citation/CS1".
  5. Script error: No such module "Citation/CS1".

Script error: No such module "Check for unknown parameters".

External links

Template:Sister project