At the 6 GeV storage ring PETRA III, DESY presently operates 25 independent insertion device (ID) beamlines. The straight sections of the ring can accommodate either one 5m long insertion device or two canted 2m devices. The standard undulators have a length of 2 m and their typical period length ranges from 29 mm to 33 mm. Several special IDs of up to 5 m length have been installed to meet the experimental requests for high energy X-rays (U21, U23), elliptically polarized light (UE65), and a higher degree of coherence. The key parameters of these devices are listed in the table below (I=100mA). Details on individual beamlines using these undulators can be found on the webpages of the PETRA III project.
|
U29 |
U32 |
U33 |
U23 |
UE65* |
U29 5m |
U36 10m |
IVU21 |
|
|---|---|---|---|---|---|---|---|---|
|
minimum magnetic gap (mm) |
9.5 |
9.5 |
9.5 |
9.5 |
11.0 |
9.5 |
12.5 |
7.0 |
|
period length λU (mm) |
29.0 |
31.4 |
32.8 |
23.0 |
65.6 |
29.0 |
36.0 |
21.2 |
|
device length L (m) |
2 |
2 |
2 |
2 |
5 |
5 |
2 x 5 |
4 |
|
number of full periods |
67 |
61 |
58 |
84 |
72 |
168 |
2 x 137 |
185 |
|
peak field B0 (T) |
0.81 |
0.91 |
0.88 |
0.61 |
1.03 |
0.81 |
0.72 |
0.76 |
|
deflection parameter Kmax |
2.2 |
2.7 |
2.7 |
1.3 |
6.3 |
2.2 |
2.4 |
1.49 |
|
energy of 1st harmonic (keV) |
3.5 |
2.4 |
2.3 |
8.0 |
0.3 |
3.5 |
2.5 |
7.8 |
|
total power Ptot (kW) |
3.0 |
3.8 |
3.5 |
1.7 |
11.8 |
7.5 |
2 x 5.9 |
5.2 |
|
on-axis power dens. (kW/mrad²) |
76 |
80 |
75 |
71 |
0.17 |
190 |
2 x 143 |
200 |
|
power in 1x1 mm² at 40 m (W) |
47 |
49 |
46 |
44 |
0.1 |
119 |
2 x 88 |
122 |
|
*circularly polarized mode |
