Tungsten SEM Filaments

EBS Tungsten EM Filaments

High quality, high stability EM cathodes

EBS Tungsten Filaments   |   Tungsten Filament Selection Table   |   Electron Source Performance Table

Introduction

The tungsten filaments manufactured by Energy Beam Sciences are used in all major brands of scanning and transmission electron microscopes. These high quality, high stability tungsten EM filaments, also called cathodes or electron emitters, are manufactured to excede the specifications of the original equipment manufacturers.  These superior cathodes are made using high quality ceramic dics, exact size contact pins and high grade tungsten filament wire. Special tools are used to produce the correct shape of the tungsten filament. All EBSciences tungsten filaments are precisely aligned and annealed in high vacuum to reduce stress in the filament. This will guarantee optimum stability, maximum brightness, longer lifetime and overall lower running costs.


Exclusive features of the EBS tungsten EM filaments are:

  • Minimum tip radius for coherent beam
  • Rigid attachment of filament wire to post to increase stability
  • Fully stress relieved for enhanced cathode lifetime
  • Polished post ends
  • Precise dimensions
  • Better long term economy
 
selection of EBS Tungsten EM Filaments

→ Please consult the following table for the correct type of tungsten filament for your SEM, TEM or Microprobe. The EBS tungsten filaments are available for FEI, Hitachi, ISI, JEOL, Philips, Tescan, Zeiss, LEO, Cambridge Instruments, Leica, AmRay and CamScan Electron Microscopes.


Tungsten Filament Selection Table 

Electron Microscope Type or Filament base       Product number Ceramic Disc mm Pin Diameter  mm Pin Pitch mm

AEI

AU-14-AE1201

12.0 1.0 6.45
AmRay /AMR (except 1200 series)

AU-14-AE1202

26.0

1.0

5.0

Cambridge Instruments (except S4-10)

AU-14-AE1201

12.0 1.0 6.45
CamScan with AEI conversion

AU-14-AE1201

12.0 1.0 6.45
CamScan with new Tescan Column

AU-14-TN1209

19.8 1.0 5.0
FEI

AU-14-FP1203

26.0 1.0 5.0
Hitachi S-Type

AU-14-HI1204

9.8 1.2 2.7
Hitachi  with Cartridge TM series tabletop
3400N, 3700N, SU1500, SU3500

AU-14-HT1205

9.8 1.2 2.7
ISI /ABT / Topcon 2-Pin

AU-14-I21206

23.4 1.2 12.0
JEOL K-Type with metal ring

AU-14-JL1208

28.0 1.2 8.0
Leica

AU-14-AE1201

12.0 1.0 6.45
LEO 400 and 1400 Series SEM

AU-14-AE1201

12.0 1.0 6.45
LEO1450 (except AEI conversions)

AU-14-ZS1210

19.8 1.0 5.0
LEO TEM

AU-14-ZS1210

19.8 1.0 5.0
Philips V-Loop (PSEM500/EM200 and later)

AU-14-FP1203

26.0 1.0 5.0
Tescan

AU-14-TN1209

19.8 1.0 5.0
Zeiss DSM and TEM

AU-14-ZS1210

19.8 1.0 5.0
Zeiss EVO

AU-14-AE1201

12.0 1.0 6.45


Electron Source Performance Table

The electron source performance table is provided to give additional information regarding the performance and requirements for different type of electron emitters. Tungsten cathodes are still used in the majority in SEMs and in general use TEMs. Improved results can be obtained with LaB6 cathodes, whereas the highest resolution can be obtained with either Schottky or cold Field Emission Sources which can only be used in suitable EMs.

Emitter Type Thermionic Thermionic Schottky FE Cold FE
Cathode Material W LaB6 ZrO/W (100) W (310)
Operating Temp (K) 2700 1800 1800 300
Cathode Radius (nm) 60,000 10,000 <1000 <100
Effective Source Radius (µm) 25 10 0.015 0.0025
Emission Current Density (A/cm2) 3 30 5300 17,000
Total Emission Current (µA) 200 80 200 5
Brightness (A/cm2.sr.kV) 1x104 1x105 1x107 2x107
Maximum Probe Current (nA) 1000 1000 10 0.2
Energy Spread @ Cathode (ev) 0.59 0.4 0.31 0.26
Energy Spread @ Source 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) <10-5 <10-6 <10-8 <10-10
Typical Cathode Life (h) 100 >1000 >5000 >2000
Cathode Regeneration (h) None None None 6-12
Sensitivity to External Influences Minimal Low Low High


Further Reading: "The Life and Death of a Tungsten Hairpin Filament"

11 Item(s)

11 Item(s)