IONS BEAM PROBE SET
It is very important to have snap estimation
of energy of incident ions flux for many technological applications
especially for precision ion sputtering equipment.
This SET is developed for Anode Layer Accelerators, but suitable for
work with another kinds of High Energy Ion Sources. See Appendix
" PROBE INVESTIGATION OF THE GRID ION SOURCE"
PROBE SET provides measurement and analysis of beam characteristics
in the range up to 3,0 keV. PROBE SET is designed for work
under intense ions flux.
- Three-electrode electrostatic analyzer is used as ion beams
- Basic sketch of three-electrode analyzer is shown below.
The main idea is to stop ions flux by applying repellent potential
UC to COLLECTOR (C).
Only ions that have energy higher than eUC can overpass
this electrostatic barrier.
It is possible to analyze energy fractions of ions
by varying UC and measuring COLLECTOR (C)
The dependence of ions current from COLLECTOR (C)
vs. potential UC is a Stopping Characteristic of ion
But it is need two additional grid electrodes for proper ions analysis.
Input Grid (G1) has a potential
UPL that is close to plasma potential in PROBE location as
shown at figure. This electrode protects a plasma from disturbance
due to high COLLECTOR (C) potential
Rejection Grid (G2) separates
ions from compensated beam rejecting electrons by negative
(relative to G1) potential
The differentiation of Stopping Characteristics gives Ions Energy
Distribution Function as a result.
PROBE SET includes:
General View and Overall Dimensions are presented on figure above.
Stainless Steel and Ceramics are materials for main
parts of PROBE.
Input Grid (G1) and Rejection Grid (G2) can be replaced
PROBE SET includes spare Grids and reserve
Collector to PROBE.
is fitted out by ATTENUATOR to measure in high intensity beams.
It is easy to adjust a PROBE sensitivity by combining with reducing
Attenuator Grids (AG) and/or Diaphragms (D).
Two-wire shielded flexible CABLE connects the PROBE to CONTROL
The CABLE is equipped by VACUUM FEEDTHRU.
The FEEDTHRU can be mount on vacuum chamber via 18mm
hole on flat vacuum wall or flange.
- The length of vacuum-side portion of the CABLE is approx
- This part has an outer armouring shield.
- The length of another portion of the CABLE is more than
The control unit generates analyzing voltage Uc with positive polarity
that supplying to probe's collector via cable connected to unit
through the coaxial HV connector. The collector voltage is varying
in manual or automatic modes in the range 50-3000V.
The control unit generates DC negative voltage supplying to rejection
grid of the probe via the cable connected through multipole connector.
The control unit measures ion current by amlifieramplifier with
digital adjustable gain and sends current and collector voltage
data through digital interface to PC-compatible computer.
The control unit is controlled be digital interface from PC-compatible
The control unit provides a some levels of protection for safety
and long-duration work.
Front View of UNIT is shown on figure.
The INTERFACE CABLE connects The CONTROL UNIT to any free LPT port
Total length is 1,5 m. DB15F to DB25M type.
Microsoft Windows 98, ME, NT, 2000
Intel Pentium 166 and higher
800х600 SVGA and higher
Free Space on HDD
more than 2MB
free LPT port
The program PROBE DAM provides operation of the probe set.
The software controls the process of measurement and data acquisition
of stopping characteristics and provides post-processing for obtaining
ions energy distribution function.
After start PROBE DAM program from Windows Start Program Menu
the main window appears as shown on figure.
Now everything is ready to accumulate, visualize
and save data.
Push START button. Stopping Characteristic
will be drawn on the screen as UC rises due to automatic mode CONTROL
UNIT. Working values of UC and ion current are displayed on
LCD-like indicators at the left side of program window also.
Push STOP button - the data will be saved in
Need a Spectrum Analysis? Just Click ANALYSE
In a few seconds Data Analysis Window with Normalized
Energy Distribution Curve will appear.
You can save this Curve as BMP file.
Questions? Comment? Mail to firstname.lastname@example.org
PROBE SET SPECIFICATIONS
OPERATING INSTRUCTIONS : html