Single and Multichannel Detector (SCD) / (MCD)
Figure 19: Detection Efficiency for Electrons and Ions
The BIAS voltage produced in the HSA3500 determines the conversion energy
E
conv
=−
q U
BIAS
E
pass
(23)
of the charged particles impinging on the CEM. The proper conversion voltage has two
requirements which must be simultaneously fulfilled:
●
the particles energy should be suitable for maximum yield of secondary electron
emission at the impact on the CEM wall. For electrons this is roughly in the en-
ergy range between 100 - 800 eV.
●
For ions, the yield increases with the kinetic energy roughly up to 10 keV.
Standard settings are:
●
for electrons: U
BIAS
= + 90 V.
●
for ions: U
BIAS
= - 2000 V.
3.5.5 Spectrometer Voltage U
0
The main retardation voltage of the spectrometer U0 is numerically equal to the differ-
ence between kinetic energy (Ekin) and pass energy (Epass) + Work Function (WF). Be-
cause of the different polarity of the lens and hemisphere voltages in the different ana-
lyzer modes (XPS,AES,UPS or ISS) the value U0 is calculated by
U
groundplate
=
E
kin
−
E
pass
−
WF
/
q
(24)
The spectrometer voltage is applied on a groundplate and lens element 10 (Figure 5:
Analyzer Main Components and Voltage Principle page 10 and Figure 33: Schematics of
the 12-pin Analyzer Feedthrough page 72 as well as the comments in section , "" on
page .
Example:
WF=4.5 eV, E
kin
=1000 eV, E
p
= 100V
33
Summary of Contents for PHOIBOS 100
Page 1: ...PHOIBOS Hemispherical Energy Analyzer Series PHOIBOS 100 PHOIBOS 150 3 1...
Page 6: ...Table of Contents PHOIBOS...
Page 10: ...Introduction 4 PHOIBOS...
Page 13: ...Electrical Connections Figure 2 Connection Scheme PHOIBOS 7...
Page 14: ...Components and Connections Figure 3 Analyzer Housing PHOIBOS100 8 PHOIBOS...
Page 15: ...Electrical Connections Figure 4 Analyzer Housing PHOIBOS150 PHOIBOS 9...
Page 42: ......
Page 51: ...SpecsLab Hardware and Software Installation PHOIBOS 45...
Page 52: ......
Page 62: ......
Page 78: ...Analyzer Checks Figure 33 Schematics of the 12 pin Analyzer Feedthrough 72 PHOIBOS...
Page 80: ......
Page 86: ......
Page 92: ...List of Figures Figure 39 Alignment Pin 84 II PHOIBOS...
Page 93: ...List of Figures PHOIBOS III...
Page 94: ......
Page 96: ......
Page 98: ...Index PHOIBOS...
