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D. Schrempf, W. Meissl, F. Aumayr:
"An ultra-compact setup for measuring ion-induced electron emission statistics";
Poster: 19th International Workshop on Inelastic Ion-Surface Collisions (IISC-19), Frauenchiemsee/Germany; 18.09.2012; in: "Book of Abstracts, 19th International Workshop on Inelastic Ion-Surface Collisions (IISC-19),", (2012), S. 59.

1. INTRODUCTION
Impact of heavy particles as atoms, molecules, positive or
negative ions on solid surfaces gives rise to electron
emission, which is of great importance for many
applications, e.g. surface and space science, sensitive
particle detection/counting, plasma wall interaction,
electrical discharges, etc. Particle-induced electron emission
is of special relevance for the registration of extremely small
particle currents, for which the statistics of the electron
emission plays a crucial role. The emission statistics (ES),
i.e. the probabilities Wn for emission of a given number n of
electrons due to a single impact event immediately permits
evaluation of the related total electron yield 􀀁 as the mean
number of emitted electrons
􀀁 􀀃 n = n 􀀄Wn ; Wn
n= 0
􀀂 􀀅
= 1
n=1
􀀂 􀀅
(1)
as well as the fraction of projectiles, which do not emit at
least one electron and which are therefore not registered by
electron emission.
2. EXPERIMENTAL SETUP
To measure the ES distribution during ion-surface
interaction usually the electrons emitted from the interaction
region are extracted by a weak electric field through a
highly transparent grid and accelerated onto a surface barrier
type detector biased at +30 kV [1 - 6]. The n electrons
emitted due to a particular ion impact will be registered like
one electron of n times 30 keV rather than n individual
30 keV electrons. The number of electrons emitted in a
particular ion-impact event can therefore be deduced from
the detector´s pulse height distribution. More details on this
ES detection method and its appropriate evaluation can be
found in [1 - 3] and refs. therein.
The usual setup for ES measurements involves a NIM crate
with detector bias, spectroscopy amplifier and power supply
operated at HV potential and a suitable data transfer from
HV to ground potential. We have now designed and
constructed a novel light and ultra-compact electronics
replacing this heavy and bulky equipment by small and light
components, which can be operated using a battery pack
only. Even the pulse height analysis is now performed at
high voltage and just the resulting pulse height spectrum is
communicated by optical fibers to the measurement PC at
ground potential. A photo and the schematics of the new
electronics is shown in fig. 1.
Figure 1: New ultra-compact ES detection electronics
Not only the compact design but also the low cost of the
new electronics presented in this contribution, will allow
other groups to easily employ the ES technique at their
beam lines and use it e.g. to determine the composition of
their HCI or cluster ion beams as described in [4, 6] or for
basic ion-surface collision studies.