Description


The ID03 beamline is illuminated by three undulators (two U35 and one U32) installed in a low-β section of the ESRF synchrotron ring. In January 2015 we have exchanged the U42 undulator for a U32 one.

 

The source size is 140x50 µm (fwhm) HxV, with a beam divergence of 210x16 µrad (fwhm) HxV.

  • The insertion device vessel has a 10 mm thickness allowing a minimum undulator gap of 11 mm.
  • The beamline is equipped with a high power front end allowing the simultaneous use of more than one undulator completely closed to the minimum gap.
  • Two undulators have a 35 mm period and the third one has a 32 mm period.

 

The next three figures give the calculated photon flux for the different undulators and the same value of the deflection coefficient K=2.3, which corresponds to a closed gap of 11 mm for the U35. The energy bandwidth for the calculations is 0.1%. The actual bandwidth for a double-bounce Si(111) crystal is about 0.01%.

source_fig1a

source_fig1b

U32..jpg

The characteristics of the new U32 undulator are:

The undulator has a peak field dependence vs gap which can be expressed as follow:
B0=B1*exp(-pi*gap[mm]/period[mm]); whith B1=1.9104 T

It has 50 periods including the end field structure. The energy of the fundamental at gap 11 mm should be 3.76 keV ( 4.25 keV at  gap 12 mm) (see tuning curve above)
The maximum power density of the U32 undulator is ~ 90 Watt/mm2 at 30 mm (gap 11 mm)

 

The values in the table below give the theoretical power, the photon energy and the flux as a function of the gap of the U35 undulator for the 1st, 3rd, 5th and 7th harmonics. The flux was calculated for the optical acceptance of the monochromator and mirror which is 5x0.7 mm @34m from the source. The energy bandwidth for the calculations is 0.1%. The actual bandwidth for a double-bounce Si(111) crystal is about 0.01%.

U35

 

1st harmonics

3rd harmonics

5th harmonics

7th harmonics

Gap [mm]

 

Power

[W]

E

[eV]

 

ph/s/0.1%

 

 

E

[eV]

 

ph/s/0.1%

 

 

E

[eV]

 

ph/s/0.1%

 

 

E

[eV]

 

ph/s/0.1%

 

 

11

179

2634

2.87E+14

7940

2.05E+14

13247

1.19E+14

18556

6.75E+13

12

163

2992

2.97E+14

9017

1.98E+14

15045

1.07E+14

21076

5.66E+13

13

148

3374

3.03E+14

10170

1.89E+14

16971

9.32E+13

23774

4.50E+13

14

134

3778

3.05E+14

11388

1.75E+14

19004

7.74E+13

26622

3.39E+13

15

121

4197

3.05E+14

12655

1.57E+14

21119

6.16E+13

29584

2.40E+13

16

110

4627

3.03E+14

13952

1.36E+14

23284

4.68E+13

32618

1.59E+13

17

99

5060

2.95E+14

15258

1.14E+14

25465

3.38E+13

35675

9.86E+12

18

88

5489

2.84E+14

16554

9.26E+13

27629

2.33E+13

38706

5.71E+12

19

79

5907

2.69E+14

17818

7.25E+13

29740

1.52E+13

41665

3.08E+12

20

70

6309

2.53E+14

19034

5.49E+13

31770

9.50E+12

44509

1.56E+12

21

62

6690

2.34E+14

20184

4.03E+13

33691

5.65E+12

47201

7.39E+11

22

54

7045

2.14E+14

21258

2.88E+13

35484

3.21E+12

49714

3.30E+11

23

47

7372

1.94E+14

22247

2.00E+13

37136

1.75E+12

52028

1.39E+11

24

40

7669

1.73E+14

23147

1.36E+13

38639

9.14E+11

54135

5.58E+10

25

34

7938

1.54E+14

23957

9.01E+12

39991

4.61E+11

56030

2.14E+10

26

29

8176

1.36E+14

24679

5.88E+12

41197

2.26E+11

57719

7.88E+09

27

25

8387

1.19E+14

25316

3.77E+12

42261

1.08E+11

0

0.00E+00

28

21

8571

1.03E+14

25875

2.39E+12

43193

5.01E+10

0

0.00E+00

29

18

8732

8.88E+13

26360

1.49E+12

44005

2.28E+10

0

0.00E+00

30

15

8871

7.63E+13

26781

9.23E+11

44706

1.02E+10

0

0.00E+00