journal menu
![[Figure 1]](gb5098fig1mag.jpg)
|
|
Figure 1
Principal scheme (top) and expected pulse energies from the X-ray to THz regime (bottom) for the example of the European XFEL. Relativistic GeV ultra-short and highly charged electron bunches first generate X-ray pulses by self-amplified spontaneous emission (SASE) in soft and hard X-ray undulators in the few mJ regime (Pellegrini, 2016  ). After passing the X-ray undulator section the electron bunches enter an additional few-period THz undulator and generate tunable, narrowband THz pulses with up to few 100 µJ pulse energy by superradiant emission (Tanikawa et al., 2019). X-ray pulse energies are calculated at saturation for electron beam energies of 8.5, 10.5, 14 and 17.5 GeV and a bunch charge of 500 pC (Schneidmiller & Yurkov, 2017). (Note that when a certain peak current is fixed, the X-ray pulse duration, and therefore its energy, will scale roughly linearly with the charge. Deviations mainly occur due to the dependence of the electron beam parameters on the bunch charge. Currently, in operations electron energies of 11.5, 14 and 16.5 GeV with a charge of 250 pC are routinely used.) |
![[Figure 1]](gb5098fig1.jpg)
 | JOURNAL OF SYNCHROTRON RADIATION |
ISSN: 1600-5775
access
