Analytical System - Pfeiffer Vacuum QualyTest HLT 260 Maintenance Instructions Manual

2.4

Analytical system

2.4.1 Detection system
The detection system essential comprises the ion source, the magnetic separation system,
and the ion collector.
The ion source ionizes neutral gas particles from which it generates an ion beam. The
positively charged ions are accelerated out of the ion source and subsequently enter the
magnetic field. There they are deflected into a circular path, the radius of which depends on
the mass/charge ratio of the ions. Only the helium ions fulfill the separation conditions and
reach the ion collector where they can be measured by the electrometer amplifier.
1 2 3
11
10
M < 4
M > 4
Fig. 12a Principle of detection system
Connetion flange
Anschlussflansch
Connection Ion soure
Anschluss Ionenquelle
Fig. 12b Design of detection system
BG 805 457 BE / C (0204) HLT 2xx
4
M = 4
Magnetic system Mass spectrometer housing
Magnetsystem Massenspektrometergehäuse
Legend:
1 Cathode 1
2 Anode
3 Cathode 2
4 Amplifier
5
5 Ion collector
6 Ion collector screen
6
7 Suppressor
8 Magnetic field
9 Intermediate orifice
10 Extractor orifice
11 Screening ring
7
Legende:
1 Katode 1
2 Anode
3 Katode 2
4 Verstärker
5 Ionenfänger
8
6 Abschirmung zu Ionenfänger
7 Suppressor
8 Magnetfeld
9 Zwischenblende
9
10 Extraktorblende
11 Abschirmring
Pre-amplifier unit EVV
Vorverstärkereinheit EVV
15