Pfeiffer Vacuum QMA 4 0 Series User manual

OPERATING INSTRUCTIONS
EN
Translation of the Original
QMA 4X0
Quadrupole Analyzer for QMG 700 HiQuad®

Dear Customer,
Thank you for choosing a Pfeiffer Vacuum product. Your new quadrupole analyzer should
support you in your individual application with full performance and without malfunctions. The
name Pfeiffer Vacuum stands for high-quality vacuum technology, a comprehensive and
complete range of top-quality products and first-class service. From this extensive, practical
experience we have gained a large volume of information that can contribute to efficient
deployment and to your personal safety.
In the knowledge that our product must avoid consuming work output, we trust that our
product can offer you a solution that supports you in the effective and trouble-free
implementation of your individual application.
Please read these operating instructions before putting your product into operation for the
first time. If you have any questions or suggestions, please feel free to contact info@pfeiffer-
vacuum.de.
Further operating instructions from Pfeiffer Vacuum can be found in the Download Center on
our website.
Disclaimer of liability
These operating instructions describe all models and variants of your product. Note that your
product may not be equipped with all features described in this document. Pfeiffer Vacuum
constantly adapts its products to the latest state of the art without prior notice. Please take
into account that online operating instructions can deviate from the printed operating
instructions supplied with your product.
Furthermore, Pfeiffer Vacuum assumes no responsibility or liability for damage resulting from
the use of the product that contradicts its proper use or is explicitly defined as foreseeable
misuse.
Copyright
This document is the intellectual property of Pfeiffer Vacuum and all contents of this
document are protected by copyright. They may not be copied, altered, reproduced or
published without the prior written permission of Pfeiffer Vacuum.
We reserve the right to make changes to the technical data and information in this document.
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Table of contents
1 About this manual 8
1.1 Validity 8
1.1.1 Applicable documents 8
1.1.2 Variants 8
1.2 Target group 8
1.3 Conventions 9
1.3.1 Instructions in the text 9
1.3.2 Pictographs 9
1.3.3 Stickers on the product 9
1.3.4 Abbreviations 9
1.4 Trademark proof 10
2 Safety 11
2.1 General safety information 11
2.2 Safety instructions 11
2.3 Safety precautions 13
2.4 Proper use 13
2.5 Foreseeable improper use 13
2.6 Responsibilities and warranty 14
2.7 Owner requirements 14
2.8 Personnel qualification 14
2.8.1 Ensuring personnel qualification 14
2.8.2 Personnel qualification for maintenance and repair 15
2.8.3 Advanced training with Pfeiffer Vacuum 15
2.9 Operator requirements 15
3 Product description 16
3.1 Structure 16
3.2 Ion sources 16
3.2.1 Axial ion source 17
3.2.2 Crossbeam ion source 18
3.2.3 Grid ion source 19
3.3 Mass filter 21
3.3.1 QMA 430 21
3.3.2 QMA 400 21
3.3.3 QMA 410 21
3.4 Secondary electron multiplier 21
3.4.1 SEV 217 21
3.4.2 Detecting negative ions 22
3.4.3 SEV 218 22
3.5 Overview of the variants 22
3.5.1 Cathode materials 22
3.5.2 Electron collimation magnet 23
3.5.3 90° deflection 23
3.5.4 90° deflection with deflection voltage 23
3.5.5 Faraday cup 23
3.5.6 Vacuum-annealed QMA 23
3.6 Identifying the product 24
3.7 Scope of delivery 24
4 Transport and storage 25
4.1 Transporting the product 25
4.2 Storing the product 25
5 Installation 26
5.1 Preparing analyzer for installation 26
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5.1.1 Choosing mounting orientation 26
5.1.2 Preparing gas inlet system 27
5.1.3 Installing support plate 27
5.1.4 Using assembling trestle 28
5.1.5 Removing transportation protection 28
5.1.6 Removing protective pipe 29
5.1.7 Installing electron collimation magnets 30
5.2 Installing analyzer 31
5.3 Connecting the gas inlet system 32
5.4 Installing HF generator QMH 40x 32
5.5 Installing EP 422 electrometer pre-amplifier on analyzer 32
5.6 Removing/installing SEM connector plate 32
5.7 Mounting ion counter pre-amplifier CP 400 33
5.8 Establishing cable connections of components 33
6 Commissioning 34
7 Operation 35
7.1 Adjusting ion source 35
7.1.1 Adjusting the axial ion source 35
7.1.2 Adjusting crossbeam ion source 35
7.1.3 Adjusting grid ion source 36
7.2 Operating analyzer at high temperature 36
7.3 Removing/installing connector plates 36
7.4 Baking out analyzer 37
7.5 Assessing sensitivity 37
7.6 Secondary electron multiplier (SEM) 37
7.7 Surface ions 38
7.8 Using degas function 38
7.9 Determining optimal parameter values 38
7.9.1 Selecting recommended operating modes 39
7.9.2 Optimization with test gas 40
7.9.3 Configuring "Emission" ion source parameter 40
7.9.4 Configuring "Protection Current" ion source parameter 40
7.9.5 Configuring "V1 Ion Reference" ion source parameter 40
7.9.6 Configuring "V2 Cathode" ion source parameter 41
7.9.7 Configuring "V3 Focus" ion source parameter 41
7.9.8 Configuring "V4 Field Axis" ion source parameter 41
7.9.9 Configuring "V5 Extraction" ion source parameter 42
7.9.10Configuring "V6/V7 Inner Deflection" ion source parameter 42
7.9.11Configuring "V8 Reserve" ion source parameter 42
7.9.12Configuring "V9 Wehnelt" ion source parameter 42
7.9.13Adjusting resolution 42
7.9.14Adapting HF cable polarity 42
8 Shipping 43
9 Recycling and disposal 44
9.1 General disposal information 44
9.2 Dispose of a mass spectrometer system 44
10 Service solutions by Pfeiffer Vacuum 45
11 Ordering information 47
11.1 Ordering parts 47
11.2 Ordering spare parts 47
12 Technical data and dimensions 48
12.1 Technical data 48
12.2 Dimensions 49
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EC Declaration of Conformity 51
UK Declaration of Conformity 52
Table of contents
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List of tables
Tbl. 1: Applicable documents 8
Tbl. 2: Abbreviations used 10
Tbl. 3: Typical values of the axial ion source 18
Tbl. 4: Typical values of the crossbeam ion source 19
Tbl. 5: Typical values of the grid ion source 21
Tbl. 6: Spare parts for QMA 4x0 47
Tbl. 7: Technical data 49
Tbl. 8: Dimensions 50
Tbl. 9: Dimensions of the ion sources 50
List of tables
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List of figures
Fig. 1: QMA with 90° off-axis SEM 16
Fig. 2: Electrode arrangement and potential curve of the axial ion source 17
Fig. 3: Electrode arrangement and potential curve of the crossbeam ion source 19
Fig. 4: Electrode arrangement and potential curve of the grid ion source 20
Fig. 5: SEV 217 21
Fig. 6: Detecting negative ions 22
Fig. 7: SEV 218 22
Fig. 8: 90° deflection with deflection voltage 23
Fig. 9: Correct alignment on the flange of the QMA with C/B ion source 27
Fig. 10: Installing support plate 27
Fig. 11: Analyzer on the assembling trestle 28
Fig. 12: Removing transportation protection 29
Fig. 13: Removing protective pipe 29
Fig. 14: Installing electron collimation magnets 30
Fig. 15: Holding vertical seal with knife blade 31
Fig. 16: Protective pipe 32
Fig. 17: SEM connector plate 33
Fig. 18: Connector plates 36
Fig. 19: Default parameters of the Ion Source Tuning program of the Quadera soft-
ware
39
Fig. 20: Optimized ion source parameters for spectrum with nitrogen and oxygen,
using a CB-IQ as an example
39
Fig. 21: Frayed peaks 41
Fig. 22: Reducing "Field Axis" 41
Fig. 23: Dimensions 49
List of figures
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1 About this manual
IMPORTANT
Read carefully before use.
Keep the manual for future consultation.
1.1 Validity
This document describes the function of the products listed in the following and provides the most im-
portant information for safe use. The description is written in accordance with the valid directives. The
information in this document refers to the current development status of the products. The document
retains its validity assuming that the customer does not make any changes to the product.
1.1.1 Applicable documents
Designation Document
Operating instructions for "HiQuad" QMG 700 BG 5400
Operating instructions for EP 422 electrometer pre-amplifier
Operating instructions for CP 400 ion counter pre-amplifier BG 5812
Operating instructions for IO 720 input-output module BG 5402
Operating instructions for QMH 4x0-x high-frequency generator BG 5982
QUADERA software documentation A component of the software
Declaration of conformity A component of these instructions
Tbl. 1: Applicable documents
You can find these documents in the Pfeiffer Vacuum Download Center.
1.1.2 Variants
This document applies to products with the following article numbers:
Article number Designation
PT M07 xxx QMA 400
PT M08 xxx QMA 410
PT M09 xxx QMA 430
You can find the part number on the rating plate of the product.
Pfeiffer Vacuum reserves the right to make technical changes without prior notification.
The figures in this document are not to scale.
Dimensions are in mm unless stated otherwise.
1.2 Target group
These operating instructions are aimed at all persons performing the following activities on the product:
●Transportation
●Setup (Installation)
●Usage and operation
●Decommissioning
●Maintenance and cleaning
●Storage or disposal
The work described in this document is only permitted to be performed by persons with the appropriate
technical qualifications (expert personnel) or who have received the relevant training from Pfeiffer Vac-
uum.
About this manual
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1.3 Conventions
1.3.1 Instructions in the text
Usage instructions in the document follow a general structure that is complete in itself. The required ac-
tion is indicated by an individual step or multi-part action steps.
Individual action step
A horizontal, solid triangle indicates the only step in an action.
►This is an individual action step.
Sequence of multi-part action steps
The numerical list indicates an action with multiple necessary steps.
1. Step 1
2. Step 2
3. ...
1.3.2 Pictographs
Pictographs used in the document indicate useful information.
Note
Tip
1.3.3 Stickers on the product
This section describes all the stickers on the product along with their meanings.
D-35614 Asslar
Mod.
P/N
S/N
Input
QMA 4x0
PT M0x xxx
...
...
Made in United States 2022/08
Rating plate
The rating plate is located on the side of the unit.
1.3.4 Abbreviations
Abbreviation Explanation
CB Crossbeam
CD Conversion dynode
EID Electron impact desorption
IQ Ion source
MSL Mean sea level
OFHC Oxygen-free high thermal conductivity
SEM Secondary electron multiplier
SEM Secondary electron multiplier
W Tungsten
About this manual
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Abbreviation Explanation
XHV Extreme ultra-high vacuum
YOx-Ir Yttriated iridium
Tbl. 2: Abbreviations used
1.4 Trademark proof
●HiQuad® is a registered trademark of Pfeiffer Vacuum GmbH.
●QUADERA ® is a registered trademark of Inficon GmbH.
About this manual
10/54

2 Safety
2.1 General safety information
The following 4 risk levels and 1 information level are taken into account in this document.
DANGER
Immediately pending danger
Indicates an immediately pending danger that will result in death or serious injury if not observed.
►Instructions to avoid the danger situation
WARNING
Potential pending danger
Indicates a pending danger that could result in death or serious injury if not observed.
►Instructions to avoid the danger situation
CAUTION
Potential pending danger
Indicates a pending danger that could result in minor injuries if not observed.
►Instructions to avoid the danger situation
NOTICE
Danger of damage to property
Is used to highlight actions that are not associated with personal injury.
►Instructions to avoid damage to property
Notes, tips or examples indicate important information about the product or about this docu-
ment.
2.2 Safety instructions
Safety instructions according to product life stages
All safety instructions in this document are based on the results of a risk assessment.
Pfeiffer Vacuum has taken into account all the relevant life stages of the product.
Risks during installation
DANGER
Danger to life caused by electric voltage on the analyzer
During operation, dangerous voltage is present on the electrode system of the QMA analyzer. Com-
ponents in the vacuum system are dangerous to touch under certain conditions. There is danger to
life due to electric voltage.
►Protect installed parts, connected units and lines against galvanic connections, flashover or
charge carrier flow.
►Make sure that the QMA, vacuum chamber, and entire apparatus always have a proper connec-
tion to protective ground.
►Provide additional protection if the user can touch the analyzer when the vacuum system is open.
►Ensure mechanical protection against contact of the analyzer and the parts installed.
►Ensure compulsory separation of the current supply when opening the system (using a door con-
tact, for example).
Safety
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DANGER
Danger to life due to dangerous contact voltage
The voltages of the IS 716 and the BIAS, TARGET and EXTR auxiliary voltages are life threatening.
►Observe the technical data of the IS 716.
►Only use professionally made cables.
DANGER
Danger to life from electric shock
The voltages under the connector plates are life threatening. Operation is not permitted if the protec-
tive pipes have been removed.
►Re-install all removed protective pipes before connecting the cables.
►Pay attention to the additional information in the corresponding chapters for special ion sources.
Risks during operation
CAUTION
Health risks and environmental damage due to the process gases used
Gases used (process gases) represent a health risk and damage to the environment.
►Check the leak tightness of the connections before introducing the process gas.
►Make sure that the exhaust gas system is suitable for the gases supplied.
►Consider potential interactions between the materials and process gases.
►When handling the gases used, observe the applicable guidelines.
►Observe the protective measures.
Risks during maintenance
WARNING
Health hazard through poisoning from toxic contaminated components or devices
Toxic process media result in contamination of devices or parts of them. During maintenance work,
there is a risk to health from contact with these poisonous substances. Illegal disposal of toxic sub-
stances causes environmental damage.
►Take suitable safety precautions and prevent health hazards or environmental pollution by toxic
process media.
►Decontaminate affected parts before carrying out maintenance work.
►Wear protective equipment.
Risks when shipping
WARNING
Risk of poisoning from contaminated products
Where products that contain harmful substances are shipped for maintenance or repair purposes, the
health and safety of service personnel is at risk.
►Comply with the instructions for safe distribution.
Safety
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Risks during disposal
WARNING
Health hazard through poisoning from toxic contaminated components or devices
Toxic process media result in contamination of devices or parts of them. During maintenance work,
there is a risk to health from contact with these poisonous substances. Illegal disposal of toxic sub-
stances causes environmental damage.
►Take suitable safety precautions and prevent health hazards or environmental pollution by toxic
process media.
►Decontaminate affected parts before carrying out maintenance work.
►Wear protective equipment.
2.3 Safety precautions
The product is designed according to the latest technology and recognized safety engineering rules.
Nevertheless, improper use can result in danger to operator all third party life and limb, and product
damage and additional property damage.
Duty to provide information on potential dangers
The product holder or user is obliged to make all operating personnel aware of dangers
posed by this product.
Every person who is involved in the installation, operation or maintenance of the product
must read, understand and adhere to the safety-related parts of this document.
Infringement of conformity due to modifications to the product
The Declaration of Conformity from the manufacturer is no longer valid if the operator
changes the original product or installs additional equipment.
●Following the installation into a system, the operator is required to check and re-evalu-
ate the conformity of the overall system in the context of the relevant European Direc-
tives, before commissioning that system.
General safety precautions when handling the product
►Observe all applicable safety and accident prevention regulations.
►Check that all safety measures are observed at regular intervals.
►Pass on safety instructions to all other users.
►Do not expose body parts to the vacuum.
►Always ensure a secure connection to the earthed conductor (PE).
►Never disconnect plug connections during operation.
►Observe the above shutdown procedures.
►Keep lines and cables away from hot surfaces (> 70 °C).
►Do not carry out your own conversions or modifications on the device.
►Observe the unit protection degree prior to installation or operation in other environments.
►Provide suitable touch protection, if the surface temperature exceeds 70 °C.
►Inform yourself about any contamination before starting work.
2.4 Proper use
The quadrupole mass spectrometer system QMG 700 HiQuad is for gas analysis in the high vacuum
range.
►Install, operate and maintain the product only in accordance with these operating instructions.
►Comply with the limits of use.
►Observe the technical data.
2.5 Foreseeable improper use
Improper use of the product invalidates all warranty and liability claims. Any use that is counter to the
purpose of the product, whether intentional or unintentional, is regarded as improper use; in particular:
Safety
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●Use outside the limits of use in accordance with the technical data
●Use for measurements whose results determine the safety of persons or large values
●Use with corrosive or explosive media
●Use outdoors
●Use after technical changes (inside or outside on the product)
●Use with replacement or accessory parts that are not suitable or not approved
2.6 Responsibilities and warranty
Pfeiffer Vacuum shall assume no responsibilities and warranty if the operating company or a third party:
●disregards this document
●does not use the product for its intended purpose
●carries out any modifications to the product (conversions, changes, etc.) that are not listed in the
corresponding product documentation
●operates the product with accessories that are not listed in the corresponding product documenta-
tion
The operator is responsible for the process media used.
2.7 Owner requirements
Safety-conscious working
1. Only operate the product in a technically flawless state.
2. Operate the product in line with its intended purpose, safety and hazard-conscious and only in
compliance with these operating instructions.
3. Fulfill the following instructions and monitor the observation of the following instructions:
–Proper use
–Generally applicable safety instructions and accident prevention regulations
–International, national and locally applicable standards and guidelines
–Additional product-related guidelines and regulations
4. Only use original parts or parts approved by Pfeiffer Vacuum.
5. Keep the operating instructions available at the place of installation.
6. Ensure personnel qualification.
2.8 Personnel qualification
The work described in this document may only be carried out by persons who have appropriate profes-
sional qualifications and the necessary experience or who have completed the necessary training as
provided by Pfeiffer Vacuum.
Training people
1. Train the technical personnel on the product.
2. Only let personnel to be trained work with and on the product when under the supervision of
trained personnel.
3. Only allow trained technical personnel to work with the product.
4. Before starting work, make sure that the commissioned personnel have read and understood
these operating instructions and all applicable documents, in particular the safety, maintenance
and repair information.
2.8.1 Ensuring personnel qualification
Specialist for mechanical work
Only a trained specialist may carry out mechanical work. Within the meaning of this document, special-
ists are people responsible for construction, mechanical installation, troubleshooting and maintenance
of the product, and who have the following qualifications:
●Qualification in the mechanical field in accordance with nationally applicable regulations
●Knowledge of this documentation
Safety
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Specialist for electrotechnical work
Only a trained electrician may carry out electrical engineering work. Within the meaning of this docu-
ment, electricians are people responsible for electrical installation, commissioning, troubleshooting, and
maintenance of the product, and who have the following qualifications:
●Qualification in the electrical engineering field in accordance with nationally applicable regulations
●Knowledge of this documentation
In addition, these individuals must be familiar with applicable safety regulations and laws, as well as the
other standards, guidelines, and laws referred to in this documentation. The above individuals must
have an explicitly granted operational authorization to commission, program, configure, mark, and earth
devices, systems, and circuits in accordance with safety technology standards.
Trained individuals
Only adequately trained individuals may carry out all works in other transport, storage, operation and
disposal fields. Such training must ensure that individuals are capable of carrying out the required activi-
ties and work steps safely and properly.
2.8.2 Personnel qualification for maintenance and repair
Advanced training courses
Pfeiffer Vacuum offers advanced training courses to maintenance levels 2 and 3.
Adequately trained individuals are:
●Maintenance level 1
─Customer (trained specialist)
●Maintenance level 2
─Customer with technical education
─Pfeiffer Vacuum service technician
●Maintenance level 3
─Customer with Pfeiffer Vacuum service training
─Pfeiffer Vacuum service technician
2.8.3 Advanced training with Pfeiffer Vacuum
For optimal and trouble-free use of this product, Pfeiffer Vacuum offers a comprehensive range of
courses and technical trainings.
For more information, please contact Pfeiffer Vacuum technical training.
2.9 Operator requirements
Observing relevant documents and data
1. Read, observe and follow this operating instruction and the work instructions prepared by the op-
erating company, in particular the safety and warning instructions.
2. Install, operate and maintain the product only in accordance with these operating instructions.
3. Carry out all work only on the basis of the complete operating instructions and applicable docu-
ments.
4. Comply with the limits of use.
5. Observe the technical data.
6. Please contact the Pfeiffer Vacuum Service Center if your questions on operation or maintenance
of the product are not answered in these operating instructions.
–You can find information in the Pfeiffer Vacuum service area.
Safety
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3 Product description
3.1 Structure
A quadrupole analyzer consists of:
●Ion source
●Mass filter with quadrupole rods
●Ion detector (SEM and deflection unit with Faraday, or only Faraday)
●Housing with flanges
Through high mechanical accuracy and the optimization of the ion-optic unit of ion source and rod sys-
tem, the analyzers achieve a high resolution, high transmission and low mass discrimination. The good
resolution and high mass range are prerequisites for using the devices to solve analytical measuring
problems. The different versions with Faraday cup or with 90° off-axis SEM and Faraday cup, as well as
the wide selection of ion sources, allow optimal adjustment to the respective measuring problem. The
open design and the low outgassing rate of the analyzers, which are designed as immersion systems,
enable exact partial pressure analyses, from high vacuum to extreme ultra-high vacuum (XHV).
1.1
1.2
1.3
1.4
1.5
75
6
4
4
3
3
1 2
8
Fig. 1: QMA with 90° off-axis SEM
1 Ion source (variants) 3 Connection flange
1.1 Axial 4 Faraday cup
1.2 Crossbeam (CB) 5 SEM
1.3 Crossbeam (gas tight) 6 Housing
1.4 Crossbeam (gas tight, with 2 gas supplies) 7 Deflection unit
1.5 Grille 8 QMA with Faraday cup
2 Mass filter
3.2 Ion sources
Ionization is achieved through ion impact. Thermal emission causes electrons to leave a heated wire
and electrical attraction fields focus them toward the ionization area. The ionization process is the most
Product description
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decisive factor for the quality of the entire analysis. Errors in this part of the process can largely not be
corrected in the later steps. Choosing the correct ion source is crucial. Closed (gas-tight) ion sources
allow gas analysis with minimal contribution of the residual vacuum. They exhibit practically no de-mix-
ing, have a high signal-to-ground ratio, low gas consumption and a low time constant.
3.2.1 Axial ion source
By focusing the ions in axial direction, the axial ion source supplies ions with a narrow energy distribu-
tion and a small speed component transversely to the axis. Excellent resolution, high sensitivity, and
good linearity are thus achieved. The open design allows recording of rapid changes in the partial pres-
sure, with minimum distortion due to self-outgassing and surface reactions.
Standard filament
W, with YOx-Ir also being available.
Application examples
●General gas analysis
●Residual gas analysis
●Desorption measurements
Function
The electrons emitted by the cathode are accelerated toward the grid of the ionization area. The Weh-
nelt electrode, which is negative to the cathode, focuses the electrons. Most of the electrons pass
through the grid and reach the lens (focus) or return to the grid. The ions produced by electron impact
are drawn out by the focus and entrance orifice and focused to the mass filter. The grid prevents the
ions from being drawn to the cathode. The field axis potential is a few volts below the potential of the
ionization area, so that mainly ions from the ionization area enter the mass filter. Ions emitted outside
the ionization area have a lower kinetic energy when they enter the mass filter. They therefore remain in
the mass filter significantly longer. Such ions are separated out almost completely.
Degas
With degassing, the outgassing rate of the axial ion source can be reduced.
●Pressure: ≤ 10-8 hPa
●Emission: ≤ 10 mA (at 550 V)
●Time: ≤ 5 minutes
100 V
0
V1
V3
V2
V4
V9
1 2 3 4 5 6
Fig. 2: Electrode arrangement and potential curve of the axial ion source
1 Cathode 4 Focus
2 Wehnelt 5 Entrance orifice
3 Ionization area 6 Rod system
Product description
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Emission 1 mA 1)
V1 Ion Reference 90 V
V2 Cathode 70 eV 2)
V3 Focus 20 V
V4 Field Axis 10 V 3)
V6 Inner Deflection 300 V
V9 Wehnelt 30 V (max. 40)
Protection Current W
YOx-Ir
4.2 A
3.5 A
Tbl. 3: Typical values of the axial ion source
3.2.2 Crossbeam ion source
The open design of the crossbeam ion source allows quick reaction to changes in the gas composition.
It has a long service life and is equipped with two filaments. The crossbeam ion source allows the direct
passage of molecular beams perpendicular and parallel to the system axis.
Standard filament
W, with YOx-Ir also being available.
Gas-tight versions
In the case of gas-tight crossbeam ion sources, the ionization area is sealed. The conductance to the
vacuum chamber is approx. 1 l/s.
Selecting operating pressure for gas-tight versions
►Select an operating pressure of <10-6 hPa in the vacuum chamber.
Application examples
●Analysis of particle beams and general gas analysis
●Qualitative and quantitative gas analyses (composition and chronological sequence)
●Analysis of reactive and aggressive gases (with special accessories)
●Detection of contamination in gases
●Isotope measurements
●Residual gas analysis on vacuum processors (e.g. plasma etching)
●Process monitoring / process control (e.g. closed-loop control of gas composition or of vaporiza-
tion sources)
●Molecular beam applications
Thanks to their minimal gas consumption, low de-mixing and low time constant, the gas-tight versions
are particularly suitable for:
●Measuring gases and solvents in fluids
●Respiration analysis
●Analysis of gas mixtures
●Trace detection thanks to less influence from the residual gas
●Corrosive or toxic gases
Function
The electrons emitted by the cathode and focused by the Wehnelt that is connected to the cathode en-
ter the ionization area through a gap and perpendicular to the system axis. In the ionization area, the
electrons ionize the gas. The ions are drawn out by the extraction electrode and focused into the mass
filter through the ion lens (focus). The electron beam, particle beam (if a molecular beam is admitted)
and ion extraction are perpendicular to each other. The field axis potential, which is a few volts below
the potential of the ionization area, mainly focuses ions from the ionization area into the mass filter.
1) At p > 5 × 10-6 hPa, reduce to 0.1 mA.
2) Before reducing V2 to < 50 eV, reduce the "Emission" to 0.1 mA and V9 to < 20 V to prevent overloading of
the cathode.
3) 5 V at mass range 1024 or 2048
Product description
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Degas
Degassing the crossbeam ion source is only recommended in exceptional cases.
●Pressure: ≤ 10-8 hPa
●Emission: ≤ 10 mA (at 550 V)
●Time: ≤ 5 minutes
100 V
-100 V
0
V1
V5
V3
V4
V2
1 2 3 4 5 6 7 8
Fig. 3: Electrode arrangement and potential curve of the crossbeam ion source
1 Wehnelt 5 Base plate
2 Cathode 6 Focus
3 Ionization area 7 Entrance orifice
4 Extraction 8 Rod system
Emission 1 mA 4)
V1 Ion Reference 90 V
V2 Cathode 70 eV 5)
V3 Focus 20 V
V4 Field Axis 15 V
V5 Extraction 250 V
V6 Inner Deflection 300 V
Protection Current W
YOx-Ir
4.2 A
3.5 A
Tbl. 4: Typical values of the crossbeam ion source
3.2.3 Grid ion source
The grid ion source has a very open design, has an extremely low outgassing rate and can be de-
gassed easily. It emits only a few surface ions. It is always equipped with two tungsten filaments.
4) With magnet 0.7 mA / At p > 5 × 10-6 hPa, reduce to 0.1 mA.
5) Before reducing V2 to < 50 eV, reduce the "Emission" to 0.1 mA and V9 to < 20 V to prevent overloading of
the cathode.
Product description
19/54

Application examples
●Residual gas analysis in UHV
●Desorption measurements
Function
The two electrons which are emitted by the ring cathode are accelerated toward the grid and mainly
pass through the grid. The ions formed inside the grid are drawn to the mass filter by the grounded en-
trance orifice. The cathode is connected in the middle; each half of it can thus be operated separately.
Degas
With the degas function, the outgassing rate of the grid ion source and the desorption of surface ions is
reduced.
●Pressure: ≤ 10-7 hPa
●Emission: ≤ 20 mA (at 550 V)
●Time: 10–15 minutes
Degassing recommendations for the grid ion source
1. Perform degassing for 10 – 15 minutes.
2. Wait for the final pressure.
3. Check the spectrum.
4. Repeat the operation if needed.
100 V
0
V1
V2
V4
1234
Fig. 4: Electrode arrangement and potential curve of the grid ion source
1 Grille 3 Entrance orifice
2 Cathode 4 Rod system
Emission 2 mA 6)
V1 Ion Reference 120 V
V2 Cathode 100 eV 7)
V4 Field Axis 10 V
6) At p > 5 × 10-6 hPa, reduce to 0.2 mA.
7) Before reducing V2 to < 50 eV, reduce the "Emission" to 0.1 mA and V9 to < 20 V to prevent overloading of
the cathode.
Product description
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