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Electron Microscope Filaments / Cathodes Overview

aei standard loop filament
Tungsten Filaments 		aei standard loop filament
Kimball LaB6 Filaments 		aei standard loop filament
Denka LaB6 Filaments


Tungsten Filaments / Cathodes for EM

Tungsten hairpin filaments are the standard type filaments widely used in Scanning Electron Microscopes, Transmission Electron Microscopes and Microprobe systems. Tungsten filaments are also called cathodes or electron emitters or electron sources. The high quality filaments we offer are made to the original equipment manufacturer's specifications using special tools to guarantee the correct shape for the filaments and to generate the optimum electron beam. The filaments are annealed i n vacuum, stress-free and precisely aligned before they are shipped. Please consult the list below for the correct type of filament for your SEM, TEM, or EPMA.

The tungsten filaments are manufactured from high grade tungsten. Of all metals in pure form, tungsten has the highest melting point (3422°C / 6192°F), the lowest vapor pressure at temperatures above 1650°C (3000°F) and has the highest tensile strength. Tungsten also has the lowest coefficient of thermal expansion of any pure metal. This combination of properties makes tungsten the ideal material.

Instrument New Filament #
AEI 1403
AMR / AMRAY (except AMRAY 1200 series) 1421
AMRAY 1200 (Siemens style) ----
Cambridge Instruments (except and S4-10) 1403
Cambridge Instruments S4-10 (Siemens style) ----
Cameca ----
CamScan standard Siemens style ----
CamScan with AEI conversion 1403
CamScan with new Tescan column 1427
ETEC 1406
FEI / Philips 1412
Hitachi S-type 1428
Hitachi Filament in Cartridge for TM3030, TM3000 and TM1000 1434
Hitachi HU-type ----
ISI / ABT / Topcon 2-pin 1425
ISI / ABT / Topcon 3-pin 1426
JEOL K-type type modern style 1407
Leica 1403
LEO 400 and 1400 Series 1403
LEO 1450 (except systems converted to AEI) 1427
MAC Probe ----
NORAN (ADAM) ----
Novascan (SEMCO) 1403
Philips V Loop (PSEM 500 and later, EM200 and later) 1412
RCA ----
Tescan 1427-1
Siemens ----
ZEISS 1427
ZEISS EVO 1403

Dimensions for EM Filament Bases Tungsten/Lab6




aei standard loop filament

AEI Base Filaments for ZEISS (EVO), LEO, AEI, Cambridge (except S4-10), Novascan, Leica

Diameter of ceramic disc: 12.0mm
Diameter of pins: 1.0mm
Center to center distance of pins: 6.45mm

Prod # Description Unit Price Order / Quote
1403 AEI Base Filaments, white base box/10 $305.10
Qty:



electron microscope filament

FEI and Philips Standard V Loop Filaments

Diameter of ceramic disc: 26.0mm
Diameter of pins: 1.0mm
Center to center distance of pins: 5.0mm

Prod # Description Unit Price Order / Quote
1412 Standard FEI/Phillips V-Loop Filaments box/10 $616.65
Qty:




electron microscope filament

JEOL K-type Filaments

Ceramic in stainless steel alignment ring.

Diameter of ceramic disc: 28.0mm
Diameter of pins: 1.2mm
Center to center distance of pins: 8.0mm

Prod # Description Unit Price Order / Quote
1407 JEOL K-type Filaments box/6 $625.00
Qty:




Hitachi S-type Filaments

(newer H-, S- and X- series)

Diameter of ceramic disc: 9.8mm
Diameter of pins: 1.2mm
Center to center distance of pins: 2.7mm

Prod # Description Unit Price Order / Quote
1428 Hitachi S-type Filaments box/10 $940.15
Qty:




Hitachi Filament in Cartridge

 

 

Prod # Description Unit Price Order / Quote
1434 Hitachi Filament in Cartridge for Table Top SEMs: TM3030plus, TM3030, TM3000, TM4000 and TM1000; and S-3400N, S-3700N, SU800, SU900. SU-1500, SU1510, and SU3500 SEMs box/10 $1766.95
Qty:




Zeiss - Tescan Filament

ZEISS (DSM Series and TEM), LEO (TEM 900 Series), LEO (SEM 1450 Series), Tescan Filaments

Diameter of ceramic disc: 19.8mm
Diameter of pins: 1.0mm
Center to center distance of pins: 5.0mm

Prod # Description Unit Price Order / Quote
1427 ZEISS/LEO (DSM, TEM, 1450) Filaments box/10 $720.50
Qty:
1427-1 Tescan Filaments box/10 718.75
Qty:




loop filament

AMRAY Filaments, except AMRAY 1200 Series

Diameter of ceramic disc: 26.1mm
Diameter of pins: 1.0mm
Center to center distance of pins: 5.0mm

Prod # Description Unit Price Order / Quote
1421 AMRAY Filaments box/10 $1274.50
Qty:




electron microscope filament

ISI / ABT / Topcon Filaments, 2-prong curved pins.

Diameter of ceramic disc: 23.3mm
Diameter of pins: 1.2mm
Center to center distance of pins: 11.9mm

Prod # Description Unit Price Order / Quote
1425 ISI 2-prong Filaments box/10 $570.00
Qty:




microscope filament

ISI / ABT / Topcon Filaments, 3-prong

Diameter of ceramic disc: 23.4mm
Diameter of pins: 1.2mm
Center to center distance of pins: 12.0mm

Prod # Description Unit Price Order / Quote
1426 ISI 3-prong Filaments box/10 $495.60
Qty:




ETEC Filament

ETEC

0.004" and 0.005" tungsten wire thickness

Prod # Description Unit Price Order / Quote
1406 ETEC Filaments box/10 $675.00
Qty:

 


Electron Source Performance Comparison

Emitter Type Thermionic Thermionic Schottky FE cold FE
Cathode material W
 LaB6
 ZrO/W (100)
 W(310)
Operating temperature [K] 2,800
 1,900
 1,800
 300
Cathode radius [nm] 60,000
 10,000
 < 1,000
 < 100
Effective source radius [nm] 15,000
 5,000
 15 (*)
 2.5(*)
Emission current density [A/cm2] 3 30 5,300 17,000
Total emission current [µA] 200 80 200 5
Normalized brightness [A/cm2.sr.kV] 1.104 1.105 1.107 2.107
Maximum probe current [nA] 1000 1000 10 0.2
Energy spread @ cathode [eV] 0.59 0.40 0.31 0.26
Energy spread @ gun exit [eV] 1.5 - 2.5 1.3 - 2.5 0.35 - 0.7 0.3 - 0.7
Beam noise [%] 1 1 1 5 - 10
Emission current drift [%/h] 0.1 0.2 < 0.5 5
Operating vacuum hPa/mbar < 1.10-5 < 1.10-6 < 1.10-8 < 1.10-10
Typical Cathode life [h] 100 > 1000 > 5000 > 2000
Cathode regeneration not required not required not required every 6 to 8 hours
Sensitivity to external influence minimal minimal low high
* virtual source


Dimensions for EM Filament Bases (for Tungsten/Lab6) Filaments?

Base Type Diameter of Ceramic disc
in mm		 Diameter of Pins
in mm		 Center Distance of Pins
in mm
AEI 12.0 1.0 6.45
FEI/PHILIPS 26.0 1.0 5.0
JEOL K-type 28.0 1.2 8.0
HITACHI S-type 9.8 1.2 2.7
ZEISS (DSM & TEM)
LEO (1450 & TEM)
TESCAN		 19.8 1.0 5.0
AMRAY (except 1200) 26.1 1.0 5.0
ISI/ABT/TOPCON
2 pins		 23.3 1.2 11.9
ISI/ABT/TOPCON 23.4 1.2 12.0