The superconducting linear accelerator of the FLASH facilities simultaneously provides electron bunches of up to 1.25 GeV energy for the two independently operating undulator lines.
For the FLASH1 facility there are 6 planar fixed gap insertion devices with a K-parameter of 1.17 and 4.5 m length each.
In addition to the six fixed gap SASE-undulators, there are four more variable gap insertion devices in the FALSH1 undulator line. They can act as a modulator for seeding the SASE-section in a High-Gain Harmonic Generation (HGHG) experiment called sFLASH. Three of these devices are identical to the U32 undulators used at PETRA III while the fourth device is a 4 m long refurbished U33 model based on the APS undulator “type A”. Their parameters are listed below.
In the course of the FLASH2020 upgrade FLASH1 shall be fully externally seeded with the full repetition rate that FLASH can provide in burst mode.
|
U32 |
U33 |
|
|---|---|---|
|
minimum magnetic gap (mm) |
9.0 |
9.8 |
|
period length λU (mm) |
31.4 |
33.0 |
|
device length L (m) |
2.0 |
4.0 |
|
number of full periods |
61 |
120 |
|
deflection parameter Kmax |
2.72 |
3.03 |
The second branch FLASH2 contains 12 planar variable gap undulators with a maximum deflection parameter Kmax = 2.81 and 2.5 m length each. In addition, FLASH2 is equppied with a Laserheater and an APPLE3 type afterburner.
The parameters for the FLASH 1 and the FLASH 2 undulators are listed in the table below.
|
ID parameters |
FLASH 1 |
FLASH 2 |
|---|---|---|
|
minimum magnetic gap (mm) |
12.0 |
9.0 |
|
period length λU (mm) |
27.3 |
31.4 |
|
device length L (m) |
4.5 |
2.5 |
|
number of devices |
6 |
12 |
|
peak field B0 (T) |
0.47 |
0.98 |
|
deflection parameter Kmax |
1.17 |
2.81 |
|
max. magnetic load Fmag (kN) |
15 |
