Erratum: Using surface impedance for calculating wakefields in flat geometry [Phys. Rev. ST Accel. Beams18, 034401 (2015)]

Bandwidth broadening of X-ray free electron laser pulses with the natural gradient of planar undulator

“…As illustrated in Fig. 1, a de-chirper device (Fu et al, 2015;Deng et al, 2014;Bane et al, 2016;Zagorodnov et al, 2015;Zhang et al, 2015;Emma et al, 2014;Novokhatski, 2015) or transverse deflecting structure (TDS) (Akre et al, 2001;Tan et al, 2014) is installed before the undulator to introduce a vertical tilt to the electron beam. It is expected that such a beam passes through a planar undulator and produce FEL radiation with large bandwidth.…”

“…A corrugated structure is usually a pipe or a pair of parallel plates with small bumps on the wall in a form of periodic ridges (Fu et al, 2015;Deng et al, 2014;Bane et al, 2016;Zagorodnov et al, 2015;Zhang et al, 2015;Emma et al, 2014;Novokhatski, 2015). For the large bandwidth FEL application the corrugated structure has small gap of millimetre order.…”

“…While if the electron beam enters the structure with an offset from the axis, travelling close to one jaw of the structure, it excite the transverse dipole wakefields, where the bunch head receive no kick while the bunch tail will be transversely kicked. On the basis of the wakefield theory (Bane et al, 2016;Zhang et al, 2015;Novokhatski, 2015), it is interesting note that the bunch tail would experience a larger transverse kick with farther distance away from axis, in condition, the transverse tilt amplitude could be also simply tuned by varying the gap of the structure. Recently, on the basis of transverse beam tilt generated by the de-chirper at LCLS, a set of multi-colour X-ray FEL experiments was successfully accomplished (Lutman et al, 2016).…”

Wakefields studies for the SXFEL user facility

“…Then the electron beam should pass through the space between two opposite magnetic poles, which can be designated as flat vacuum chamber. Therefore, the short-range resistive wall wake effect arisen from metallic wall can be calculated by the formulas [14,15]. The surface characteristics of vacuum chamber shows to be more complex under the observation of atomic Submitted to Chinese Physics C microscopy [16] and surface roughness wake [17,18] appears relatively small, thus the real shape could be simplified in terms of conductive wall with smooth surface only.…”

Coulomb-Driven Relativistic Electron Beam Compression

“…In this method, the electron beam is first sent through an rf buncher cavity where the bunch head is decelerated to lower energy while the bunch tail is accelerated to higher energy; after passing through a dispersive element (typically a drift for keV and MeV electrons or a magnetic chicane for ultra-relativistic electrons (see, e.g. [14])), the bunch tail may catch up with the bunch head, leading to bunch compression. While this method has been widely used in UED and FEL community, it is also realized that the phase jitter in the rf cavity leads to considerable timing jitter which limits the temporal resolution achievable [15,16].…”