Comparison of EDS to WDS

Comparison of EDS to WDS, Equal Beam Current

- pure Si and Fe, 10-11 A (0.01 nA), 25 KeV, 60 sec

   

P (cps/10-8 A)

P/B

CDL(ppm)

Si Ka

EDS

5400

97

580
 

WDS

40

1513

1,710

Fe Ka

EDS

3000

57

1,000
 

WDS

12

614

4,900

(from Goldstein, et. al. 1988)

Comparison of EDS to WDS, Optimized Conditions

- 15 KeV, 180 seconds counting time
- EDS : 2 x 10-9 A (2 nA) to give 2K cps spectrum to avoid sum peaks
- WDS : 3 x 10-8 A (30 nA) to give 13K cps on Si spectrometer (< 1 % dt)

   

Peak cps

P/B

CDL(ppm)

EDS

Na Ka

32.2

2.8

1,950

EDS

Mg Ka

111.6

6.4

1,020

EDS

Al Ka

103.9

5.7

690

EDS

Si Ka

623.5

22.8

720

EDS

Ca Ka

169.5

8.5

850

WDS

Na Ka

549

83

210

WDS

Mg Ka

2183

135

120

WDS

Al Ka

2063

128

80

WDS

Si Ka

13390

362

90

WDS

Ca Ka

2415

295

90

(from Goldstein, et. al. 1988)

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