Embed Size (px)
Citation preview
NASA
vacuum challenges and solutions
August 2009
PWVacSuppAug09Cover_p01.indd 1 20/7/09 15:21:49
The New Varian TPS-compact:Your Winning Move!
Varian, Inc.Vacuum Technologies
Canada and US Toll Free Number: 800.882.7426Europe Toll Free Number: 00.800.234.234.00
www.varianinc.com/vacuum
The new unique dry TPS-compact is a portable,fully integrated turbo pumping systempowered by the Turbo-V 81 MacroTorr or
Turbo-V 301 Navigator pumps, backedby the Varian 60 l/min IDP-3 Dry Scrollnew generation primary pump. The TPS-compact is the most innovativeproduct of the new TPS TurboPumping Systems product family.
The TPS-compact is a cost-effectivepumping solution that can be used world-wide, it is easy to use and complieswith world-wide safety standards.
• Dry, Clean, Compact, Light and Robust System
• Improved Vacuum Performance
• Unique Varian Turbo Pump Technology
• Unique Varian IDP-3 Dry Scroll Pump
• On board direct pressure reading
• Active Gauge Capability
• Voltage 110-220 V - CE/CSA certified
• RS-232 or Analogical Communication
• World-wide Service and Support
The New Dry Turbo Pumping System from Varian: TPS-compact
Pag Varian Robot TPS_PW 20-07-2009 11:46 Page 1
Users of vacuum equipment are as diverse as the applications that they explore and the challenges that they face. This special supplement to Physics World considers how they overcome these problems – large and small. Trying to recreate the vacuum of space here on Earth is a big chal-lenge with an even bigger solution – the largest vacuum chamber in the world (p7), while meeting the demands of a burgeoning steel industry also calls for expansive solutions as manufacturers move to dry pumping systems (p13) in order to save both money and the planet. At the heart of all good measurements lie good standards, and vacuum metrology (p18) gives users the confidence to trust their equipment. Getting the best from that equipment is vital, so a forum where users can share their experi-ences is a useful way of honing skills. The RGA User Group (p11) offers those working with residual gas analysers the chance to do just that. The Kelvin probe may not be as well known as the residual gas analyser, but this versatile surface-analysis tool is set to become a favourite with users (p5). Diamonds may be a girl’s best friend, but novel amorphous diamond coatings are attracting the attention of those users needing the key combi-nation of hardness and low friction (p15). How vacuum users continue to challenge and be challenged should make for an interesting future.
Vacuum challenges and solutions
ContentsKelvin probe is ready for mainstream 5Once a niche instrument, Iain Baikie reveals why the Kelvin probe, a simple surface-analysis tool, is now set to take centre stage.
Chamber simulates space on Earth 7Using the biggest vacuum chamber on Earth to recreate the conditions of space is all in a day’s work for NASA’s Stan Grisnik.
RGA User Group offers broad appeal 11Robin Hathaway extols the benefits to users, old and new, of a forum where they can share their experiences of residual gas analysers.
Dry vacuum aids steel degassing 13The manufacture of high-performance steel is a growth industry, Simon Bruce and Vic Cheetham explain how dry vacuum pumps can improve production processes.
Diamond coatings are branching out 15Chris Walker describes how Adamant, a new amorphous, low-friction version of diamond, is the latest material to sparkle in the world of coatings.
Towards portable vacuum standards 18How do you calibrate pressure-measurement gauges back to the pascal? Jay H Hendriks and Douglas A Olson square up to the challenge.
TEMPERATURE CONTROLLERS
2 OR 4 CHANNELS
OPERATION TO <60mk
DUAL CONTROL LOOPS
ETHERNET CONNECTED
TEMPERATURE MONITORS
2, 4 OR 8 CHANNELS
OPERATION TO <200mk
ETHERNET CONNECTED
DATA LOGGING
TEMPERATURE SENSORS
CRYOGENIC ACCESSORIES
Innovative Solutions in Cryogenic
Instrumentation
©2009 IOP Publishing Ltd. All rights reserved.Dirac House, Temple Back, Bristol BS1 6BE, UK.
PWVacSuppAug09Contents_p03.indd 1 20/7/09 14:47:36
Delivering Expert Solutions for Vacuum, Surface & Nanoscience
Scanwel Ltd, Llandderfel, Bala, Gwynedd LL23 7HW, UK. Tel: +44 (0)1678 530281. Fax: +44 (0)1678 530320
SP CS SPM 150 Aarhus with KolibriSensor™ and Nanonis Control System
www.scanwel.co.uk
Making vacuum easy – from off the shelf hardware to complete custom systems
Scanwel three chamber xhvoutgassing test system, with <10–11 mbar base pressure for JoeHerbert (ASTeC Vacuum ScienceGroup Daresbury Laboratory).
• “Superclean” chambers separatedby “sealed” Variable Orifice Disc
• xhv pumping based on turbopumps in series and all metal gatevalves
• 250oC quick fit bakeout system
• Fast “heated” Entry lock for transfer to low maintenancesample outgassing stage for TPDstudies
• Multiple RGA heads and “extractorgauges”
• Simple manual control system withpower failure safe condition
Competitively pricedhardware is available fromstock. For a full listing,including details of thisamazing offer visit oureasy to use on-line shop
OFFER of the month
Key benefits
• Outstanding mechanical and thermal stability
• Ultrafast handling. In situ sensor preparation
• Independent and simultaneous recording of force and tunnellingsignals
The NC-AFM image (left) shows the atomicallyresolved surface of KBr at room temperature(image size 4 x 4 nm, imaging speed 2.5 linesper second).
The newly redesigned Scanning Probe Microscope SPM 150 Aarhus withKolibriSensor™ delivers ultimate STM and dynamic AFM performance over awide temperature range, from 90K to 400K. In combination with the ultra-low-noise Nanonis Control System with digitally integrated PLL, it is now easierthan ever to obtain routine atomic resolution in both STM and NC-AFM mode.
are exclusively represented byScanwel in the UK and Ireland
AVB-CF70Viton Sealed Valve
Usually £238 Less 20%Offer Price £190.40
Untitled-22 1 21/7/09 09:22:12
V a c u u m c h a l l e n g e s a n d s o l u t i o n s a u g u s t 2 0 0 9 5
Kelvin probe is ready for mainstreamIn 1898 the great Victorian physicist and inventor later Lord Kelvin connected two plates coated in two different met-als to a galvanometer. These were slowly pushed very close together, and a tiny electrical current flowed through the meter. Kelvin measured the voltage that arises from the difference in the work functions of the metals (the work function being the amount of energy required to remove an electron from the surface of a metal).
His work led to the Kelvin probe (KP) – a simple, versatile surface-analysis tool. It may not yet be regarded as a mainstream surface-analysis technique for measurements of work function or surface potential, however, its ease of operation, temperature and pressure compatibility, and high surface sensi-tivity suggest that it should be on every vacuum-chamber planner’s “wish list”.
The KP is an “equilibrium” tech-nique, but it is electrical rather than thermal in nature and allows for very-high-precision measurements. Many vacuum applications involve the depo-sition or growth of atomic or molecu-lar thin films. These can modify the original work function by more than 100–1000 mV. With a basic resolution of 1–3 mV, the KP permits a highly detailed picture of the surface to be developed throughout the deposition process. This means that the influence of dif-ferent variables, such as sample preparation and deposition parameters, can be studied very closely.
At the heart of a KP is a vibrating metallic tip that is usu-ally made from stainless steel. The tip is brought close to a sample using either a manual or a motorized translation stage. The result is a dynamic capacitor with capacitance in the tens to hundreds femtofarad range.
Either the substrate or the surface film must be a conduc-tor. An electrical contact, typically via the sample holder, is made between this “active” part of the sample and the tip. The spatial resolution of the tip is macroscopic – diameters of 20–0.05 mm are feasible. In general it is advisable to opt for larger tips initially and then change to smaller diameters if higher spatial resolution is required.
When the sample and tip are electrically connected, charge flows from the surface with the lowest work function (high-est Fermi level) to that with the higher work function (lowest Fermi level), and current flows between the two at the tip’s frequency of oscillation – typically 60–100 Hz. In the “null-field approach” KP, a variable DC voltage is applied between surface and tip to cancel the potential difference. This point
is detected as an absence of the signal. Hence, changes in the voltage (surface potential or work function) of the sam-ple can be recorded in real time.
As a PhD student at Twente University in the Netherlands in the early 1980s, I developed a more powerful, “off-null” method. This involves “steering” the potential so that measurements are made at large signal levels, rather than attempting to measure the noise in the vacuum system at balance. This method comes with the additional advantage that the mean KP capacitance can be auto-matically monitored and, with appropri-ate system design, all of the electrical and mechanical parameters required to establish an ideal measurement regime can be determined. Most importantly, these parameters can be held constant for a range of samples, allowing results to be compared.
KP works at atmospheric pressure right down to the lowest vacuum pres-sures achievable and also from cryogenic temperatures up to 1000 K. Applications include “work function engineering” of anode and cathode surfaces, device passivation, thin films, surface adsorp-tion, fuel cells, surface corrosion and hydrogen storage.
KP is particularly useful for charac-terizing semiconductors (both traditional and organic) and is now being used in the development of solar cells. If light is shone underneath the tip, the subsurface electrical character-istics of the topmost dielectric-semiconductor layers can be studied in a non-destructive fashion that was not previously possible. This DC surface-photovoltage technique typically involves large changes in surface potential (70–400 mV) and is probably more valuable than traditional AC surface-photo-voltage analysis because the relevant time constants are often in the range of seconds to minutes.
In 2000 I was so convinced of the commercial potential of KP that I founded KP Technology. Based in Wick, it now employs 10 people, has 12 representatives worldwide and counts more than 350 companies as customers. I foresee a rosy future, particularly as this is a relatively inexpensive tool (~10% of the cost of an electron spectrometer). I hope that it will be widely adopted in appropriate university courses, and that future vacuum-chamber designers will consider it to be an essential tool.Iain Baikie is CEO of KP Technology Ltd, Wick, and is a visiting professor at the Nanotechnology and Integrated Bio-Engineering Centre at the University of Ulster, Belfast, e-mail ibaikie@kelvinprobe@info
Iain Baikie, founder of KP Technology, describes the Kelvin probe and explains why it is a welcome addition to many vacuum chambers.
Iain Baikie envisages a rosy future for uses of his surface-analysis technique.
PWVacSuppAug09Baikie_p05.indd 5 20/7/09 14:48:31
Tel: 01249 782610
CLIENT: Goodfellow
PROJECT: Physics World Full Page Advert
STATUS: Initial Mac Designs – Option 2
Standard and custom made products in
Pure Metals, Alloys, Polymers, Ceramics,
as well as many Composites and
Compounds in various forms
including foil, rod, tube,
wire, powder, etc.
All available on our
secure website –
and with a 5%
discount!
Standard and custom made products in Standard and custom made products in
Pure Metals, Alloys, Polymers, Ceramics, Pure Metals, Alloys, Polymers, Ceramics,
as well as many Composites and as well as many Composites and
Compounds in various forms Compounds in various forms
including foil, rod, tube, including foil, rod, tube,
wire, powder, etc.wire, powder, etc.
All available on our All available on our
secure website – secure website –
and with a 5% and with a 5%
discount!
Metals & Materials. Solutions for research and industry
www.goodfellow.com
Goodfellow Cambridge Limited
Ermine Business Park
Huntingdon, PE29 6WR
Tel: 0800 731 4653
or +44 1480 424 800
Fax: 0800 328 7689
or +44 1480 424 900
E-mail: [email protected]
Untitled-3 1 22/10/07 10:42:27
The cost of failure of a space mission is millions or even bil-lions of dollars and, more importantly, could lead to loss of life. So testing spacecraft is an important part of developing new ways to travel into space. Those that carry personnel, such as the Orion capsule – part of NASA’s Constellation programme to return astronauts to the Moon – must function properly in the severe conditions of space to ensure the health and safety of the individuals on board.
The Space Power Facility (SPF) at NASA’s Glenn Research Center’s Plumbrook Station in Sandusky, Ohio, is the world’s largest space-simulation chamber used to test spacecraft. The cathedral-like chamber is 37 m tall and 30 m across, with a volume of around 23 000 m3. The facility – known as a thermal vacuum chamber – can reproduce both the temperature and pressure of space. The latter can vary from around 10–3 mbar at 50 km from Earth to 10–6 mbar at 170 km away.
Craft for testing can have a mass of up to 270 tonnes and either be built in the chamber or brought in prefabricated via
two 15 × 15 m doors and three sets of standard-gauge rail tracks. The temperature can be adjusted from –150 to 50 °C by a “thermal surface” with an area of about 1500 m2. A craft is not placed in direct contact with the surface, which means that its temperature change is due to radiation heat transfer. The temperature-controlled surface is cooled by a huge container with a million litres of liquid nitrogen and two 2.2 MW gas compressors. Infrared quartz lamps – simulat-
Chamber simulates space on EarthStan Grisnik describes how NASA’s huge craft-testing facility can recreate the vacuum conditions of space.
Inside the Space Power Facility in Sandusky, Ohio.
NASA
PWVacSuppAug09Grisnik_07.indd 7 20/7/09 14:49:30
8 V A C U U M C H A L L E N G E S A N D S O L U T I O N S A U G U S T 2 0 0 9
J A N I S
Janis Research Company 2 Jewel Drive Wilmington, MA 01887 USATEL +1 978 657-8750 FAX +1 978 658-0349 [email protected]
Visit our website at www.janis.com
.10 mK to 800 K .Cryocoolers.LHe/LN2 Cryostats
Cryogenic Systems
.Magnet Systems.Dilution Refrigerator Systems.Micro-manipulated Probe Stations
Does your research require low temperatures?Contact Janis today. Our engineers will assist youin choosing the best system for your application.
Cryogensystems-CERN 2/3/09 10:57 AM Page 1
ing the radiation heat transfer from the Sun – are arranged around the object to be tested.
The SPF chamber can be pumped down from atmospheric pressure to high vacuum in less than 20 h using a unique technique. “Roots pumps”, which consist of two fi gure-of-eight-shaped lobes or impellers that rotate at 1500–3500 rpm, are fi rst used to quickly remove the large volume of air. These work not by the principle of gas expansion and compression but by moving a volume of gas. The pumping speed is set by the internal volume of the pump multiplied by the rotational speed of the pump, so a physically bigger pump has a higher pumping speed. Evacuating the chamber is done via groups of Roots pumps in parallel, known as “stages”, which have a common inlet and a common outlet pressure. For example, a two-stage system has a fi rst stage consisting of a group of pumps that remove air from the vacuum chamber, and exhaust it into a second stage of pumps that then pumps the chamber to a lower pressure.
At the SPF the fi rst stage has four Roots pumps arranged in parallel and connected to the vacuum chamber through a 1.2 m diameter pipe. This stage evacuates the chamber from atmospheric pressure to 600 mbar in about 20 min. Two Roots pumps in parallel with a 60 cm inlet piping then evacuate the chamber to 390 mbar in another 20 min before two Roots pumps with 45 cm diameter inlet piping reduce the pressure to about 170 mbar after an additional 20 min. The fourth stage, consisting of two pumps with 35 cm inlet piping, reduces the pressure to 90 mbar in a further 20 min.
Finally, six rotary piston pumps in parallel with 15 cm inlet piping kick in to bring the chamber to 0.0133 mbar in an addi-tional 30 min. Rotary piston pumps use a piston to expand and compress a gas, similar to an air compressor. The fi fth stage then exhausts to atmosphere.
These fi ve stages of pumps remove 53 tonnes of air, and then they are isolated from the chamber so that the helium cyropumps can come online to remove the remaining 700 g of air. Helium cryopumps operate by freezing the air inside the vacuum chamber and then collecting it on the cold sur-faces of the pumps, which are at a temperature of 15 K. When enough ice has built up on the cold surfaces, the pumps must be warmed to release the air. This type of pump can only operate under vacuum conditions. After around 70 min the chamber vacuum level is reduced to 3 × 10–5 mbar by 10 helium cryo-pumps. The vacuum level is reduced to less than 10–7 mbar in an additional 3–10 h.
We recently tested the air-bag landing system for the Mars Exploration Rover mission by simulating the conditions that would be experienced when landing on the Martian surface. This revealed that the air bags would be torn to shreds dur-ing the actual landing of the Spirit and Opportunity rovers. Without ground testing, and overcoming these issues with the help of the SPF, the rovers would have crash-landed on Mars at a cost of around $820 m.Stan Grisnik is a senior thermal vacuum systems engineer for the SPF at NASA’s Glenn Research Center, e-mail [email protected]
www.lewvac.co.ukLewVac LLP, Unit F2, Ote Hall FarmJanes Lane, Burgess Hill, RH15 0SR
Tel : +44 (0)1444 233372 Fax : +44 (0)1444 233392Email : [email protected]
PWVacSuppAug09Grisnik_07.indd 8 20/7/09 14:49:58
Untitled-1 1 6/7/09 15:45:52
PWVSAug09_p09.indd 1 20/7/09 13:16:05
THIN FILMS ANDSURFACE ENGINEERING
In the analysis of gases, radicals and ions in surfaceengineering and thin film applications, Hiden Analyticalproducts offer:
� plasma characterization� SIMS - nano thin film
analysis� RGA - vacuum
process analysis
14. Quadrupole massspectrometers
for surface analysis,vacuum process analysis,thin film composition,ion mass and energy analysis,time resolved analysis
for further details of Hiden Analytical products contact:
Q u a d r u p o l e s f o r a d v a n c e d s c i e n c e
H3Ad14-thinfilm:PhysicsWorldVacSupp 14/7/09 15:09 Page 1
Untitled-2 1 10/7/09 11:32:45
PWVSAug09_p10.indd 1 20/7/09 13:21:01
V a c u u m c h a l l e n g e s a n d s o l u t i o n s a u g u s t 2 0 0 9 11
The RGA User Group was originally formed to coordinate informal meetings for users and manufacturers of residual gas analysers (RGAs) to help them better understand each others needs and hence derive potential benefits. The first meeting of the group took place in 1996 in Rugby and com-prised just 11 attendees. Since then the group has organ-ized meetings approximately every 18 months. Attendance has grown steadily, culminating in the last meeting, held in March 2008 at the Culham Laboratory in Oxfordshire, which attracted more than 70 participants from industry, manufac-turing and academia.
The RGA is an analytical instrument that is widely used throughout the vacuum industry. Its origins are as a diag-nostic tool for measuring the partial pressures of the gases present in a vacuum chamber after it has been pumped down. However, advances in electronics and software have meant that the RGA is now revealing its true worth as a mass spectrometer, covering a variety of applications that are far removed from just measuring the quality of the vacuum.
The range of process-vacuum areas where RGAs are employed has widened to span everything from semiconduc-tor processing to the extreme high vacuum (XHV) require-ments of the latest generation of particle accelerators. The biggest benefit for users is that this range of applications has resulted in a significant market for RGAs that is filled by many different manufacturers, with the outcome that there is lots of product choice and such instruments can now be purchased at relatively low cost.
To the uninitiated, one RGA may look very much like another, but not all are the same, and this is where the group can help to enlighten users about the optimum set-ups for different vacuum processes and applications. Having an informed understanding of such intricacies is seen as a grow-ing necessity for a large number of users, and the RGA User Group strives to address this need by providing opportunities for users, both new and old, to share their practical experi-ences of the instrumentation.
The user group has grown from humble beginnings to pro-vide an established forum for the exchange of information and practical advice. It organizes workshop-style meetings with the aim of bringing industrial, academic and research-based RGA users together with equipment suppliers and manufac-turers. These events are normally held at the laboratories of large UK government-research facilities. The events are free to all attendees, thanks to support from the companies attend-ing the small exhibitions run in conjunction with the one-day meetings. The group also receives financial support from the Institute’s Vacuum Group and ASTeC, the UK’s centre of expertise for accelerator science and technology.
A typical meeting consists of eight or nine short presenta-tions by experts from academia and industry that might cover everything from the practical aspects of using and servicing instrumentation to the latest advances in equipment mini-aturization. The schedule offers attendees lots of time for networking with other users and with manufacturers, which helps to facilitate collaboration and the transfer of ideas. The meeting is usually rounded off with a tour of the facilities where the event is being held. An archive of presentations from meetings, together with other RGA User Group infor-mation, is available at rgausers.org.
The group is currently making plans for its next meeting, RGA-9, which will take place early next year. This will be another milestone in the evolution of the RGA User Group because it will form part of what it is hoped will be the first in a series of new vacuum events for the UK. Vacuum Symposium UK aims to address the needs of the vacuum community with an annual event incorporating both techni-cal and commercial elements.
The 1st Vacuum Symposium UK (VS-1) will take place on 10–11 February 2010 at the Daresbury Laboratory in Cheshire. The meeting will be free to participants and the event will run over two days, with the RGA-9 programme forming day one and a complementary VS-1 programme running on day two. The event will include free training seminars for new vacuum users, technical talks for more-experienced attend-ees and a vacuum-equipment exhibition. It is hoped that the event will attract interest from across the entire UK vacuum industry and beyond. So, if you are a user of vacuum equip-ment, have an interest in vacuum science and technology or are a supplier/manufacturer of vacuum equipment, then this meeting is for you. Full details and registration options are available at vacuum-uk.org.
Just as RGAs offer broad appeal, so the RGA User Group looks to do the same.Robin Hathaway is chair of the RGA User Group committee, e-mail [email protected]
Robin Hathaway explains how a user group provides a forum for sharing experiences and discovering new ways to exploit the powerful diagnostic features of residual gas analysers across a wide range of applications.
RGA User Group offers broad appeal
PWVacSuppAug09Hathaway_p11.indd 11 20/7/09 14:50:43
012
VACU
UM V
ALVE
S 20
VACU
UM V
ALVE
S 20
1
VACU
UM V
ALVE
S 20
12012
012
New VAT Catalogue
Request your copy today! www.vatvalve.com
Pump IsolationRoughing
Specialities
XHV
Control
Transfer
www.vatvalve.com
Swiss Headquarters Tel ++41 81 771 61 61 [email protected]
VAT Benelux Tel ++31 30 601 8251 [email protected]
VAT France Tel (01) 69 20 69 11 [email protected]
VAT Germany Tel (089) 46 50 15 [email protected]
VAT U.K. Tel 01926 452 753 [email protected]
VAT USA Tel (781) 935 1446 [email protected]
VAT Japan Tel (045) 333 11 44 [email protected]
VAT Korea Tel (031) 662 68 56 [email protected]
VAT Taiwan Tel (03) 516 90 88 [email protected]
VAT China Tel (021) 5854 4300 [email protected]
VAT Singapore Tel 6252 5121 [email protected]
Catalog_Ad_YI0902EA_210x140_GB.indd 1 04.03.09 09:36:35Atom/Ion Source
e-Beam Evaporator
ww
w.t
ec
tra
.de
from € 20.000
from € 8.900
Anz Atom_Ion Source e-Beam 2008.1 1 28.01.2008 18:12:57 Uhr
ULTRA HIGH VACUUMHigh Precision: Goniometers – Manipulators
XYZ Translators – Rotary Motion DrivesRotary Linear Motion Drives – Stepper Motor Drive Systems
Designed and Manufactured to suit Customers Specifications
Panmure Instruments LtdBuilding 109, New Greenham Park, Newbury, Berks RG19 6HN
T: +44 (0)1635 42305 F: +44 (0)1635 528221Email: [email protected]
Panmure Draft 1 19/9/06 15:41 Page 1
PWVSAug09_p12.indd 1 20/7/09 13:23:30
V a c u u m c h a l l e n g e s a n d s o l u t i o n s a u g u s t 2 0 0 9 13
The market for high-performance steels has experienced sig-nificant growth, driven by the needs of infrastructure projects in many regions, especially China, India, Russia, Eastern Europe and South America. Much of this demand is met by melting down scrap steel and using secondary steel-making processes, such as vacuum degassing (VD) and vacuum oxy-gen decarburization (VOD), to control impurity levels.
VD is usually associated with making “long products”, such as rails and beams. Liquid steel is held for a period of time under a good vacuum (typically <1 mbar) and purged with inert gas to remove lighter impurities and dissolved gases, especially hydrogen. The final hydrogen content of steel has a significant impact on its properties and durabil-ity. Less hydrogen means greater strength and resistance to cracking over the product’s lifetime.
VOD is mainly used to reduce the carbon content of special stainless steels. A medium vacuum of around 100–200 mbar is used to facilitate controlled carbon removal from the steel (decarburization) by injecting oxygen gas onto the liquid-steel surface, before continuing to a VD phase.
Both VD and VOD are often used in electric arc furnace (EAF) facilities, which process recycled scrap steel. EAFs are a flexible way of making a variety of different steels in relatively short timescales. Adding VD/VOD capability allows high-value products to be made when required.
The traditional method of providing a vacuum for VD/VOD processes is large multistage steam ejector pump sys-tems, fed by steam boilers. These systems consume a con-siderable amount of energy, generate significant greenhouse gases and can be a source of hazardous air pollutants. Many melt-shop owners are turning to dry mechanical vacuum pumping systems, which offer both significant cost savings and environmental benefits.
Dry vacuum pump technology has undergone continuous development to keep pace with the demands of industry. In the steel industry, vacuum processes must operate under harsh conditions, such as abrasive dusts. Dry screw primary vacuum pumps have proved successful in these conditions, and the latest generation of double-ended dry screw pumps combine high pumping capacity with high tolerance to abra-sive dusts. These pumps form the basis of Edwards’ modular pumping systems for steel-degassing plants.
Each dry pumping module comprises two stages of mechan-ical vacuum boosters in front of the third (final) stage dry screw pump. A module can degas around 23 tonnes of liquid steel in about 20–25 min, so a number of parallel modules are installed in each plant according to the “heat” size – the mass of liquid steel in each batch.
Additional modules can be added if production increases. Modularization results in more compact equipment that uses less electrical power, cooling water and purge gas. It also
offers the ability to refine system operating characteristics to meet the exact needs of the process and makes the transport, installation and commissioning of equipment easier.
The modular three-stage steel-degassing system offers sig-nificant operational cost savings compared with conventional steam ejectors. The cost of energy for steam generation, rou-tine maintenance for ejector cleaning and the strong demand for utility water, plus disposal costs of contaminated waste water, result in a significantly lower operating efficiency and higher net operating cost compared with dry systems.
The dry pumping systems, in contrast, require only mod-est amounts of electrical power, purge gas and cooling water. On a typical VD plant processing 300 000 tonnes of steel per year, and depending on plant configuration and utility costs, the operating costs of a dry modular system can be less than 10% of the equivalent steam ejector system. This can rep-resent potential savings of more than 71 per tonne of steel processed, offering a short payback time.
The demand for dry vacuum pumping systems for VD and VOD processes has grown substantially. Edwards recently signed a contract to supply China’s Chong Qing Steel Group Co with the world’s largest mechanical vacuum pumping system, to be used for degassing 230 tonne quantities of liq-uid steel in each batch. The pumping capacity of this system will be a world-beating 1000 000 m3/h pumping speed at a vacuum level of 0.67 mbar.
The trend away from traditional steam ejectors towards dry modular vacuum pumping systems for steel degassing is expected to continue for the foreseeable future.Simon Bruce, Edwards Ltd, Dolphin Road, Shoreham-by-Sea BN43 6PB, UK; Vic Cheetham, Edwards Ltd, Wingates Industrial Estate, Westhoughton, Bolton BL5 3XU, UK
Dry vacuum aids steel degassingSimon Bruce and Vic Cheetham of Edwards Ltd examine how steel-degassing plants are replacing steam ejectors with modular dry vacuum pump systems.
Degassing pumping modules made by Edwards and installed in a production facility.
Edwards
PWVacSuppAug09Bruce_p13.indd 13 20/7/09 14:51:23
A D V E R T I S I N G F E AT U R E
SAES® Getters’ advanced getter technology is adoptedfor the Karlsruhe Tritium Neutrino experiment (KATRIN)
The KATRIN experiment, resulting from the joint work of several European and US Institutions, is a next generation beta-decay experiment designed to measure the electron neutrino mass with a sensitivity of 0.2 eV [1]. This ambitious project is located at the Forschungszentrum Karlsruhe (FZK) Institution and improves on the size and precision of previous experi-ments by an order of magnitude. The KATRIN project is extremely demanding regarding the vacuum requirement, with the largest vessel being the 200 Ton main Spectrometer with a volume of 1250m3 that has to be maintained at pressures below ≈ 10-11 mbar [2]. Figure 1 shows arrival of the main Spectrometer at FZK – photo courtesy of KATRIN [3].
To help meet this challenging pressure target SAES Getters has worked closely with KATRIN FZK scientists to provide several kilometers of non-evaporable Zr- V-Fe alloy getter strips (a specifically modified version of the St707 type) which were integrated into cylindrical cartridges (Figure 2 – courtesy of KATRIN [2]).
These cartridges have been designed and optimized for sticking probability and interference effects using Monte Carlo simulation techniques, and have resulted in a pump utilizing 1km of St707 strip that provides a pumping speed of ~300 m3s-1 for H2 at 15°C [1].
Non Evaporable Getter (NEG) materials are well known in vacuum technology to be an effective means of removing molecules through the process of chemisorption on the getters’ active surface, and also for providing high sorption capacity through thermally driven diffu-sion of the sorbed gas into the getter bulk. The getter material is carefully prepared by SAES in the form of sintered bodies or, as in the case of the KATRIN experiment, laminated getter strip.
SAES® Getters Group, the worldwide market leader in getter components for sealed-off devices and vacuum tubes, provides a wide range of Non Evaporable Getter (NEG) pumps and tailor-made NEG pump devices for supporting UHV-XHV applications.
Further details on SAES Getters products are available via the SAES Getters website and through local SAES Getters Group Sales Offices.
For more information: Dr. Andy Hayden
European Sales Manager- Industrial Applications
e-mail: [email protected] www.saesgetters.com
[1]Day C H, Luo X, Conte A, Bonucci A, Manini P. JVST, 2007. [2]Day C H, Gumbsheimer R, Wolf J, Bonn J, “1250 m3 @ 10-9 Pa: One of the KATRIN Challenges”. Presentation from AVS2006, San Francisco. [3]KATRIN Website: http://www-ik.fzk.de/tritium/spectrometer/index.html
CCMay09AdSAES x.indd 1 7/4/09 14:10:12
Untitled-17 1 20/7/09 14:44:03
Advertise your vacancy to a global audience
on the new jobs website from IOP Publishing.
www.brightrecruits.com
Advertise your vacancy to a global audienceon the new jobs website from IOP Publishing.
www.brightrecruits.com
Advertise your vacancy to a global audienceon the new jobs website from IOP Publishing.
www.brightrecruits.com
PWVSAug09_p14.indd 1 20/7/09 15:23:52
V a c u u m c h a l l e n g e s a n d s o l u t i o n s a u g u s t 2 0 0 9 15
ALS & ALLOYS
3 4 5 6 7 8 9 10 11 12
13 14 15 16 17
18
44.9562.991541
Scandium
Sc2147.8674.511668
Titanium
Ti2250.9426.111910
Vanadium
V2351.9967.141907
Chromium
Cr2454.9387.471246
Manganese
Mn2555.8457.871538
Iron
Fe2658.9338.901495
Cobalt
Co2758.6938.911455
Nickel
Ni2863.5468.92
1084.6
Copper
Cu2965.397.14419.5
Zinc
Zn3069.7235.9029.8
Gallium
Ga3172.645.32938.3
Germanium
Ge3274.9225.73816.9
Arsenic
As3378.964.82221
Selenium
Se3479.904
3.12-7.3
Bromine
Br3583.803.733
-153.22
Krypton
Kr36
10.8112.462076
Boron
B512.0112.273900
Carbon
C614.0071.251
-195.79
Nitrogen
N715.9991.429
-182.95
Oxygen
O818.9981.696
-188.12
Fluorine
F920.1800.900
-246.08
Neon
Ne10
26.9822.70660.3
Aluminium
Al1328.0862.331414
Silicon
Si1430.9741.8244.2
Phosphorus
P1532.0651.96
115.2
Sulphur
S1635.4533.214-34.04
Chlorine
Cl1739.9481.784
-185.85
Argon
Ar18
4.00260.177
-268.93
Helium
He2
88.9064.471526
Yttrium
Y3991.2246.511855
Zirconium
Zr4092.9068.572477
Niobium
Nb4195.9410.282623
Molybdenum
Mo42[98]11.52157
Technetium
Tc43101.0712.372334
Ruthenium
Ru44102.9112.451964
Rhodium
Rh45106.4212.021554.9
Palladium
Pd46107.8710.49961.8
Silver
Ag47112.418.65321.1
Cadmium
Cd48114.827.31156.6
Indium
In49118.717.31231.9
Tin
Sn50121.766.70630.6
Antimony
Sb51127.606.24
449.5
Tellurium
Te52126.90
4.94113.7
Iodine
I53131.295.887
-108.05
Xenon
Xe54
174.979.841652
Lutetium
Lu71178.4913.312233
Hafnium
Hf72180.9516.653017
Tantalum
Ta73183.8419.253422
Tungsten
W74186.2121.023186
Rhenium
Re75190.2322.613033
Osmium
Os76192.2222.652466
Iridium
Ir77195.0821.091768.3
Platinum
Pt78196.9719.301064.2
Gold
Au79200.5913.55-38.83
Mercury
Hg80204.3811.85304
Thallium
Tl81207.211.34327.5
Lead
Pb82208.989.78271.3
Bismuth
Bi83[209]9.20254
Polonium
Po84[210]
–302
Astatine
At85[222]9.73
-61.85
0Radon
Rn86
[262]–
1627
Lawrencium
Lr103[262]
––
Rutherfordium
Rf104[262]
––
Dubnium
Db105[266]
––
Seaborgium
Sg106[264]
––
Bohrium
Bh107[277]
––
Hassium
Hs108[268]
––
Meitnerium
Mt109[281]
––
Darmstadtium
Ds110[272]
––
Unununium
Uuu111[285]
––
Ununbium
Uub112[289]
––
Ununquadium
Uuq114
Solids & Liquids (g/cm3) Gases(g/l)
�
Melting point (Solids & Liquids) • Boiling point (Gases)
�
Standard Catalogue Items
Element Name
SymbolAtomic weight
DensityM.pt./B.pt.(˚C)
AtomicNo. ADVENT
[284]––
Ununtrium
Uut113[288]
––
Ununpentium
Uup115[292]
––
Ununhexium
Uuh116
June 2006
METALS & ALLOYS • Foils • Sheets • Plates • Wires • Insulated wires • Wires straight cut lengths • Woven wire meshes • Rods • TubesPellets • Lumps • Ingots • Polymers • for Research/Development & Industry • Small quantities • Competitive prices • Fast shipment
*Lanthanoids
**Actinoids
Solids & Liquids (g/cm3) Gases(g/l)
�
Melting point (Solids & Liquids) • Boiling point (Gases)
�
Element Name
SymbolAtomic weight
DensityM.pt./B.pt.(˚C)
AtomicNo.
www.advent-rm.com£ • � • Sfr • US$+ new stock lines
Advent Research Materials Ltd • Eynsham • Oxford • England OX29 4JA
ADVENT
Order on line Visit our website for latest Catalogue prices
Tel + 44 1865 884440 Fax + 44 1865 884460 [email protected]
June 2006
1
21.00790.090
-252.87
Hydrogen
H1
6.9410.54180.5
Lithium
Li39.01221.851287
Beryllium
Be4
22.9900.9797.7
Sodium
Na1124.3051.74650
Magnesium
Mg12
39.0980.8663.4
Potassium
K1940.0781.55842
Calcium
Ca20
85.4681.5339.3
Rubidium
Rb3787.622.63777
Strontium
Sr38
132.911.8828.4
Caesium
Cs55137.333.51727
Barium
Ba56
[223]––
Francium
Fr87[226]5.0700
Radium
Ra88
138.916.146920
Lanthanum
La57140.126.689795
Cerium
Ce58140.916.64935
Praseodymium
Pr59144.246.801024
Neodymium
Nd60[145]7.2641100
Promethium
Pm61150.367.3531072
Samarium
Sm62151.965.244826
Europium
Eu63157.257.9011312
Gadolinium
Gd64158.938.2191356
Terbium
Tb65162.508.5511407
Dysprosium
Dy66164.938.7951461
Holmium
Ho67167.269.0661497
Erbium
Er68168.939.3211545
Thulium
Tm69173.046.57824
Ytterbium
Yb70
[227]10.071050
Actinium
Ac89232.0411.721842
Thorium
Th90231.0415.371568
Protactinium
Pa91238.0319.051132
Uranium
U92[237]20.45637
Neptunium
Np93[244]
19.816639
Plutonium
Pu94[243]
–1176
Americium
Am95[247]13.511340
Curium
Cm96[247]14.78986
Berkelium
Bk97[251]15.1900
Californium
Cf98[252]
–860
Einsteinium
Es99[257]
–1527
Fermium
Fm100[258]
–827
Mendelevium
Md101[259]
–827
Nobelium
No102
57-70
*
89-102
**
METALS & ALLOYS
Diamond coatings are branching out
Diamond – hard, sparkling and bright – has been revered for thousands of years as a gemstone. Nowadays it is also widely used in industry, with the first papers on “polycrystalline” diamond having been published as far back as 1911. However, it was not until 1971 that Sol Aisenberg and Ronald Chabot at Whitaker Corporation in the US discovered a new form of carbon that had the same form of bonding as diamond, but that was amorphous rather than crystalline. Created using ion-beam deposition, these thin films were coined “diamond-like carbon” (DLC) and are now used in everything from razor blades to computer hard disks.
Since then, researchers have worked hard to study the properties of DLC, which follows the contours of the sur-face rather than “filling in” the peaks and valleys. It is also highly smooth, its low friction arising from the relatively large proportion (65%) of diamond-like sp3 bonds between pairs of carbon atoms and the relatively small proportion
(35%) of graphite-like sp2 bonds, which makes it amorphous rather than crystalline. Indeed, researchers at the Fraunhofer Institute in Germany have characterized different types of DLCs according to how they are formed and the percentage of sp2, sp3 and (sometimes) hydrogen bonds.
Another interesting feature of DLC is that it can be depos-ited onto substrate materials at temperatures of 200–300 °C, whereas polycrystalline materials have to be deposited at a much higher 800–1200 °C and so cannot be coated onto substrates that change phase below this temperature. Unfortunately, it
Adamant is a hard, low-friction amorphous diamond material created using plasma-assisted chemical vapour deposition.
Chris Walker looks at some of the uses of a novel amorphous diamond material.
PWVacSuppAug09Walker_p15.indd 15 20/7/09 14:52:11
16 V a c u u m c h a l l e n g e s a n d s o l u t i o n s a u g u s t 2 0 0 9
is not easy to produce useful DLC films that are thicker than about 3–5 μm because the high temperatures used to make them generates stresses inside the materials, which then expand on their substrates. Now, however, Diamond Hard Surfaces Ltd has developed and patented a process for producing a material that bridges the gap between traditional DLCs and polycrystalline diamond.
The result is a hard, low-friction amorphous material, named Adamant, that can be applied in thicknesses of 40 μm and beyond, which is an order of magnitude higher than other technologies. Created using a patented plasma-assisted chemical vapour deposition (CVD) process operating at less than 100 °C, the material has a hardness of 3500–4000 on the Vickers hardness (HV) scale as a result of its very high proportion (~99%) of sp3 bonds. (The hardness of tungsten carbide, in comparison, is only 2000 HV.) The process uses ultra-high-vacuum conditions and involves splitting up carbon-containing molecules, with the resulting ions being accelerated towards the surface of a substrate on which tet-rahedrally bonded carbon (i.e. diamond) is formed.
Adamant has many potential applications, particularly those where bulk materials (e.g. tungsten carbide) and coat-ings (e.g. hard chrome) are used in thick layers of up to 100 μm. Indeed, since Adamant is 12–15 times as wear-re-sistant as tungsten carbide and about twice as hard, any film made from it will last far longer than a tungsten-carbide film of the same thickness. That hardness makes the material use-ful for oil and gas firms that send drill bits and other moving
parts long distances down underground shafts to reach the source of fuel. Adamant is also being used to make every-thing from long-life cam shafts for the motor-sport indus-try, where engines are not allowed to be opened up between races, to sharp, longer-lasting knives to cut plastic sheets as they roll off an industrial production line.
Adamant, which is transparent to infrared light, could also be used in the defence and aerospace industries. For example, the infrared light that missiles use to guide themselves to a target is usually directed through a sapphire window. Coating the sapphire with Adamant would make it much tougher and reduce the possibility of the window becoming damaged due to the abrasive effect of air rushing past. Another advantage is Adamant’s “green” credentials: it does not need much energy to be made, uses harmless precursors and does not need any energy-intensive pre- and post-processing.
Owing to the low deposition temperature, the material can be coated on a variety of substrates, such as copper, alu-minium, silicon carbide, tungsten carbide, titanium and even plastics, such as polyetheretherketone. The process is scal-able and our company has just completed a new facility to make Adamant in large enough quantities to satisfy customer demand. There is plenty that we do not yet know about the boundaries between amorphous carbon and polycrystalline diamond, and our company is hoping to fill that gap.Chris Walker is chief executive of Diamond Hard Surfaces Ltd, Towcester, Northamptonshire, UK, e-mail [email protected]
Untitled-16 1 20/7/09 14:19:50
PWVacSuppAug09Walker_p15.indd 16 20/7/09 14:52:36
Other deposition Systems:Atomic Oxygen, hydrogen, nitrogen sources - Ion
sources - K-cells - sputter deposition - E-beam Evaporators
Size-selected nanoparticles
Ultra-pure process
Adherent coatings
Magnetic materials
Oxides, nitrides, alloys
[email protected]: +44 1844 260160www.mantisdeposition.com
NanoParticle Deposition
TechCon2010April 17–22, 2010 • Orlando World Center Marriott Resort and Convention Center • Orlando, FL
Golf Tournament
April 19–22, 2010
April 17–22, 2010
April 20–21, 2010
Technical ProgramEducation ProgramExhibit
www.svc.orgFor information on the 53rd AnnualTechnical Conference, visit us on-line at
Golf Tournament
www.svc.org Local Attractions
PWVSAug09_p17.indd 1 20/7/09 15:22:44
18 V a c u u m c h a l l e n g e s a n d s o l u t i o n s a u g u s t 2 0 0 9
Towards portable vacuum standards
Since the middle of the 17th century, when Italian physicist Evangelista Torricelli discovered that a glass tube filled with mercury could be used to measure atmospheric pressure, liquid-column manometers have been used as a primary standard to measure pressure. Even today, they operate on the same principle that pressure can be determined if you know the density and the differential height of a liquid-col-umn manometer, as well as the acceleration due to gravity.
The problem with making reliable pressure measurements in modern research and industrial processes, which can range from ultra-high vacuum (10–8 Pa) to atmospheric pressure (105 Pa), is that many kinds of gauges are required – from ion-ization and spinning-rotor gauges to capacitance-diaphragm and resonant-silicon gauges. However, the improper use or incorrect calibration of any of these can result in unreliable measurements that cost time and money.
It is therefore vital that gauges should be traceable to the SI system of units, which have been accurately measured by standards laboratories, such as the National Institute of Standards and Technology (NIST) in the US and other national metrology institutes around the world. Indeed, developing and maintaining suitable high-accuracy stand-ards that allow traceability to the SI units is one of the most significant challenges in vacuum metrology. Standards labs are thus responsible for developing these standards for the unit of pressure – the pascal (Pa).
The NIST Pressure and Vacuum Group operates and main-tains mercury and oil liquid-column manometer standards that use pulsed ultrasound interferometry to determine col-umn heights. In this technique a transducer at the bottom of each liquid column generates a pulse of ultrasound (typi-cally ~10 MHz) that propagates up the column, is reflected from the liquid–gas interface and returns to be detected by the transducer. The change in phase of the returned signal is proportional to the length of the column, enabling length changes to be detected with a resolution of 10–20 nm. These primary pressure standards cover 1 mPa – 360 kPa, with un -certainties as low as 5.2 ppm at atmospheric pressure.
The problem is that primary-standard ultrasonic interfer-ometer manometers (UIMs) contain lots of mercury and can only achieve their low uncertainties when operated by skilled personnel in a low-vibration environment with extraordinary temperature control. The UIM at NIST, for example, is in a lab where the temperature is controlled to 0.1 K and measure-ments are made to within 0.003 K. What metrology institutes, secondary calibration labs, businesses and universities all need are high-stability standards that are easy to transport.
Economic trade agreements require standards labs to com-
pare their primary pressure standards to verify that they are equivalent in achieving the pascal. Additionally, manufac-turers and users of pressure gauges want to calibrate their products at their own facilities to save time and money. To address these issues, our group has developed a transportable transfer standard package (TSP) that delivers an SI-traceable calibration with only slightly higher uncertainties than those that could be obtained directly against NIST’s UIM primary pressure standard.
A common transfer standard is the capacitance diaphragm gauge (CDG), in which the deflection of a diaphragm is proportional to the applied pressure. CDGs have excellent resolution and short-term calibration stability: long-term cal-ibration drift for recalibrated CDGs is typically only 0.5%.
The calibration stability of the CDG has, however, been a limiting factor in realizing lower calibration uncertainties for low-pressure measurements. For example, NIST’s UIM cali-brated CDGs provide SI traceability to the pascal for vacuum standards that operate at a much lower pressure (i.e. at higher vacuums). These NIST vacuum standards, which operate by delivering precise flows of gas to ultra-high-vacuum chambers with an orifice of known conductance, are used to calibrate spinning-rotor guages (SRGs) and ionization gauges (IGs).
The SRG operates on the principle that a magnetically levi-tated and spinning metal ball will decelerate as gas molecules strike it. The IG, meanwhile, works because the gas inside it is ionized and the resulting ion current is proportional to pressure. These gauges are not considered primary standards and therefore they must be calibrated. It is the unbroken-chain of calibration that allows a NIST-calibrated IG or SRG to be traceable to the SI though the NIST UIM. In the example
Jay H Hendriks next to NIST’s ultrasonic interferometer manometer, which provides traceability to the pascal.
Jay H Hendricks and Douglas A Olson examine the challenges of calibrating pressure-measurement guages for vacuum standards.
NIST
PWVacSuppAug09Hendriks_p18.indd 18 20/7/09 14:53:23
V a c u u m c h a l l e n g e s a n d s o l u t i o n s a u g u s t 2 0 0 9 19
above, the calibration stability of the CDGs is a weak link and NIST began exploring transfer standards with higher calibration stability.
In the mid-1990s the use of microelectromechanical systems (MEMS) enabled pressure-sensor technology to become much more precise and accurate. In particular, reso-nant silicon gauges (RSGs), which contain two single-crystal silicon resonators encapsulated in a vacuum microcavity, use tiny diaphragms made by micromachining silicon. Changes in pressure on the diaphragm are determined by measuring strain-induced changes in the two resonant frequencies.
Over the past decade, repeated calibration of these gauges has shown that they are very stable, rugged and ideally suited as core technology for a high-stability transfer standard that can be calibrated against primary UIM pressure standards. The RSG sensors (10 kPa and 130 kPa full-scale gauges) have excellent long-term calibration stability of 0.01%, which is over an order of magnitude better than the CDGs. One snag with the RSGs is that their pressure sensitivity is much lower than high-accuracy CDGs below 100 Pa.
Our group at NIST has thus developed and built several high-stability TSPs that are based solely on RSGs or on a hybrid of both CDG and RSG technology. These combine a low full-scale range, excellent resolution and the good short-term stability of the CDGs with the excellent long-term sta-bility of the RSGs. By using the RSG to calibrate the CDG at the time of use, the measurement uncertainty of the CDG is reduced by a factor of 10 or more. The hybrid RSG–CDG
technology is housed in a NIST-designed temperature-con-trolled enclosure that further improves the operational stabil-ity of the RSGs and CDGs.
The TSPs consist of a pressure transducer package (PTP) – containing commercially available RSGs and CDGs, mani-folds and valves, as well as an ion pump and UHV gauging to maintain and monitor the reference vacuum – as well as sup-port electronics to control, operate and acquire data from the PTP with a laptop computer and custom-designed software. NIST scientists have recently shown that the uncertainty due to calibration stability is in the range of 1–2 ppm at 100 kPa, rising to 0.01% at 100 Pa (Metrologia 44 171).
NIST is currently using these TSPs to provide pressure references for our vacuum-gauge calibration services. Other uses include international comparisons of pressure and a pre-cision atmospheric pressure standard for a secondary-cali-bration facility in the US. These transfer standards are also expected to find applications in international “round-robin” comparisons of pressure standards that will validate, and potentially lower, uncertainty claims of pressure and vacuum measurements conducted at secondary-calibration laborato-ries as well as industrial and academic research facilities.Jay H Hendricks is the NIST Low Pressure Manometry Project leader and NIST seminar instructor of the 2009 pressure and vacuum measurement course, e-mail [email protected]. Douglas A Olson is the NIST Pressure and Vacuum Group leader in Gaithersburg, MD, US, e-mail [email protected]
PWVacSuppAug09Hendriks_p18.indd 19 21/7/09 09:16:27
Our proven ceramic ball bearing technique provides extreme dura-bility under a wide range of operating conditions. Fitting with lifetime lubricated ceramic ball bearings is part of the extensive recital of advantages found in our new turbomolecular pump generation, the TURBOVAC SL. These turbomolecular pumps with mechanical rotor suspension and compound stage excel through a new compact design, improved vacuum performance and a standardized acces-sories program. In addition, the pumps can be mounted in virtually any position and at any angle. The turbomolecular pumps from the TURBOVAC SL product family have been designed to handle the most advanced and demanding applications and requirements in research and industry.Get the details at vacuumdetails.oerlikon.com
Ceramic ball bearings you can rely on for a lifetime.
Looking for a durable relationship?
©B
ICO
M_1
001
8.02
0.
02.2
009
Oerlikon Leybold Vacuum GmbHBonner Strasse 498D-50968 KölnT +49 (0)221 347-0F +49 (0)221 [email protected]/leyboldvacuum
0901LV_TURBOVAC SL_E.indd 1 06.02.2009 13:54:40 Uhr
