产品详情
  • 产品名称:Apertures光圈

  • 产品型号:60001
  • 产品厂商:其它品牌
  • 产品文档:
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简单介绍:
Characteristics and Cleaning of Apertures Platinum Melting Point: 1768°C (3214.4°F) Molybdenum Melting Point: 2610°C (4730°F) Tungsten Boat Melting Point: 3422°C (6191.6°F) (With coated ceramic Al2O3
详情介绍:

Characteristics and Cleaning of Apertures

Platinum Melting Point: 1768°C (3214.4°F)
Molybdenum Melting Point: 2610°C (4730°F)
Tungsten Boat Melting Point: 3422°C (6191.6°F)
(With coated ceramic Al2O3 tabs)

Aperture contamination occurs when it is exposed to the electron beam, in which case regular cleaning or replacement is required. The smaller the hole, the more quickly contamination builds up and astigmatism increases. Dirty aperture systems make alignment difficult due to beam deflection caused by dirt charging up.

Platinum/Iridium apertures may be cleaned by flaming them and applying temperature where the aperture does not exceed a color of cherry-red (not white-heat). Bunsen burner or small flame devices (alcohol, butane) have been used for this procedure. About 10-15 seconds should be sufficient for this procedure. "Flamers" for this purpose are described below. The entire surface will reach the same color when completely clean.

Molybdenum apertures must be heated in a vacuum below 10-4 mbar. After proper vacuum is reached and current applied, a color of cherry-red is achieved. Use a tungsten boat. This will require about 20-30 seconds. Molybdenum apertures can be successfully cleaned more frequently and used again, than Platinum/Iridium.

Platinum/Iridium disc apertures can be flamed in our platinum gauze "Aperture Flamer" (No. 60001) for cleaning purposes. Other Aperture Flamers (No. 60003, 60004) are shown for Platinum/Iridium discs, small and large, and for hanging strip Platinum/Iridium apertures.

The cleaned aperture(s) should be inspected on a clean glass slide at 30-40X. The hole should be clean and round. Misshapen apertures should be rejected.
 

Standard Small Cup

For aperture discs (up to 6mm) or aperture strips while flaming. 4.7mm (3/16") diameter cup. 0.152mm (6 mil) platinum foil with 0.8mm (1/32") diameter hole to encourage a good air flow. A 0.76mm (30 mil) platinum wire attaches the cup to the heat resistant handle. A hook formed at the wire-cup attachment may be used for hanging an aperture strip and flaming
Prod # Description Unit
60003
Small Cup Aperture Flamer w. handle and cover
each

Large Cup

 

Large CupFor aperture discs 6 – 12mm (1/4"–1/2") or aperture strips while flaming. A flat pan is fabricated from. 0.152mm (6-mil) platinum foil with a 0.8mm (1/32") diameter hole to encourage a good airflow. A 0.76mm (30-mil) platinum wire attaches the cup to the heat resistant handle. A hook formed at the wire-cup attachment may be used for hanging and flaming aperture strips.

Prod # Description Unit
60004
Large Cup Aperture Flamer w. handle and cover
each

Molybdenum, Platinum and Tantalum Metal Boats

7.9mm W x 76.2mm L (5/16" W x 3" L)
Trough: 4.8 W x 12.7mm (3/16" W x 1/2" L) x .8mm (1/32") deep
Material strip thickness: 0.05mm (0.002")
Used for aperture cleaning
Prod # Description Unit
81
Molybdenum Boat, 3/16" x 1/2" trough
pkg/5
82
Platinum Boat, 3/16" x 1/2" trough
each
83
Tantalum Boat, 3/16" x 1/2" trough
pkg/5

Molybdenum Metal Boat (long) for Strip Aperture Cleaning

Molybdenum Metal Boat (long) for Strip Aperture Cleaning.
12.7mm W x 76.2mm L (1/2" W x 3" L)
Trough: 9.6mm W x 50.8mm L (3/8" W x 2" L) x 1mm (.04") deep.
Material strip thickness: 0.05mm (0.002")
Prod # Description Unit
80-1
Molybdenum Boat, 3/8" x 2" trough
pkg/5

Tungsten Metal Boat (long) for strip aperture cleaning

9mm W x 76mm L (3/8" W x 3" L)
Trough: 6.5mm W x 50mm L (1/4" W x 2" L) x 1mm (0.04") deep
Material strip thickness: 0.025mm (0.001")
Used for aperture cleaning
Prod # Description Unit
80-2
Tungsten Boat, 1/4" x 2" trough
pkg/5


 
Platinum Gauze Aperture Flamer

Platinum Gauze cup and stem, with handle. Length 190mm; basket 8mm dia. x 9mm high.
Prod # Description Unit
60001
PELCO Aperture Flamer
each

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