X18B CHARACTERISTICS:

Parameters of X18B
X18B: Channel-cut monochromator with weak link (detuning)
three low-noise ion-chambers (Oxford)
13-element Ge-detector (10-12 decent elements)
closed-cycle He-refrigerator
Lytle-detectors and accessories
●Energy range 4.8-40keV
●Intensity 1·1010Hz
●Energy linearity ±0.8eV between 5.9 and 9.6keV
●Energy resolution 2·10-4-5·10-4
●Q-range up to 18Å-1 in some metal standards
●Sensitivity 100-1000ppm with PIPS, 10-20ppm with 13-element Ge-detector

 

The Intensity, Energy Linearity and Energy Reproducibility at X18B.

 

Intensity at X18B, Nov 9, 2006.

 

Beam Size = 10 mm x 1 mm., 20 m from the source, collecting 0.5 mrad, horizontal.

The Oxford ion chamber has 0.08 V as offset.

Standard Ion Chamber has air

Oxford ion chamber is sealed with 100% N2 at atmos. pressure.

 

Energy- KeV

Standard Ion chamber

Current- nA

Photons / s / 100 mA beam current x 10E10

Oxford Ion Chamber

Keithley 10E7 gain (V)

Photons / s / 100 mA beam current x 10E10

Ring Current-mA

6.5

90.65

1.043

6.59

1.834

255.4

7.0

109.35

1.459

6.83

2.128

255.1

7.5

120.41

1.847

6.73

2.348

254.8

8.0

126.77

2.218

6.48

2.527

254.5

8.5

126.82

2.513

6.04

2.626

254.3

9.0

122.72

2.737

5.53

2.671

254.1

9.5

116.46

2.904

4.98

2.662

253.9

10.0

107.99

2.995

4.43

2.612

253.6

11.0

90.67

3.119

3.59

2.595

248.3

12.0

75.86

3.113

2.79

2.385

247.9

13.0

62.74

3.016

2.23

2.220

247.7

14.0

51.47

2.853

1.79

2.046

247.4

15.0

41.72

2.626

1.42

1.838

247.0

16.0

33.32

2.351

1.12

1.621

246.8

17.0

25.66

2.001

0.87

1.390

246.6

18.0

19.43

1.658

6.39(E8)

1.114

246.2

19.0

14.748

1.357

4.84

0.911

246.1

20.0

11.177

1.099

3.67

0.737

245.9

21.0

8.470

0.8834

2.80

0.596

245.7

22.0

6.426

0.7040

2.14

0.478

245.6

23.0

4.866

0.5564

1.65

0.385

245.4

24.0

3.672

0.4354

1.26

0.306

245.2

25.0

2.788

0.3396

0.98

0.243

245.1

26.0

2.137

0.2667

0.76

0.193

244.9

27.0

1.613

0.2054

0.59

0.153

244.8

28.0

1.209

0.1562

0.45

0.118

244.6

29.0

0.922

0.1200

0.35

0.0927

244.5

30.0

0.707

0.0925

0.28

0.0747

244.3

 

 

 

 

 

 

 

 

 

 

 

 

 

file:x18bflux-std-Oxfd.dat

 

Intensity as function of energy (X18B)

 

Detune 30% for < 9 KeV, 20% for >= 9 KeV but <14 KeV, 10% for >= 14KeV but < 15 KeV

Full tuned at >= 15 KeV.

Vertical slit size 1 mm for < 15 KeV, 0.5 mm for >= 15 KeV