Speaker
N. Fil
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P2.4018.pdf
Experimental studies of electron emission properties under magnetic field
for copper samples: effect of the surface morphology.
N. Fil 1,2,3, J. Hillairet1, M. Belhaj2, J. Puech3, R. Mathevet4
1
CEA, IRFM, Saint Paul-lez-Durance, France
2
ONERA-The French Aerospace Lab, Toulouse, France
3
CNES-The French National Centre for Space Studies, Toulouse, France
4
LNCMI-Intense Magnetic Fields Laboratory, Toulouse, France
Magnetic confinement fusion devices [1], particle accelerators [2] and space communication
payload [3], among other applications, are concerned by multipactor effect. This undesirable
phenomenon is a resonant process which can lead to power handling limitation of RF
components [4]. To determine the multipactor power threshold, experimental tests or/and
simulations are commonly used. The power threshold is closely related to the electron emission
properties of the RF component materials. Accurate power threshold predictions by simulations
should be based on the use of accurate electron emission propriety data [5]. In some situations
[1]–[3], the RF components are submitted to DC magnetic fields which might affect the electron
emission properties and hence the multipactor power threshold.
In a collaborative effort between French research centres CEA, CNES and ONERA, a new
experimental setup specially designed to investigate the effect of DC magnetic field on the
electron emission properties was developed. In this paper, we first describe the development of
the experimental setup and the optimisation of the associated measurement methodology. Then
we show and analyse the total electron emission yield (TEEY) measurements made on copper
samples under magnetic field perpendicular to the sample surface. We have studied various
surface morphologies such as laminated and polished and have observed TEEY increase as well
as decrease depending on the magnetic field amplitude and the surface morphology. With
incident electron at first cross-over energy (EC1), DC magnetic field has a greater influence on
the laminate surface than the polished one (respectively TEEY decreased to 45% and 5%). Such
impact of the magnetic field must be considered on multipactor effect simulations codes.
[1] J. de Lara, et al. Garcia-Baquero, IEEE Trans. Plasma Sci., vol. 34, no. 2, pp. 476–484, 2006.
[2] G. Rumolo, et al., Phys. Rev. Spec. Top. - Accel. Beams, vol. 4, no. 1, pp. 25–36, 2001.
[3] M. Goniche, et al., Nucl. Fusion, vol. 54, no. 1, p. 13003, 2014.
[4] J. R. M. Vaughan, Electron Devices, IEEE Trans., vol. 35, no. 7, pp. 1172–1180, 1988.
[5] N. Fil, M. Belhaj, J. Hillairet, and J. Puech, Phys. Plasmas, vol. 23, no. 12, p. 8, 2016.
