I.M.H.O. the Mass Spectrometer is the most useful instrument ever
invented for anyone involved with vacuum systems. The graph at the
head of this page was made with an ancient,much modified VG
Micromass partial pressure analyzer that also has seen service as a
Sharp eyed readers have also noted that there is a leak in the
system indicated by the mass 32 peak. It was due to a bad weld and
didn't show up until after bake-out.
Dr. Steve Taylor, of Liverpool University, recently recently gave a
talk here about his work building a quadropole vacuum gas analyzer
with MEMS technology.
Some hastily scribbled notes:
- A quad built entirely on silicon chips-
- Disposable due to low costs and the ability to make in
- Filters can easily be paralleled.
- Small physical size (2 cm quad rods, rods are low cost
- 6 Mhz. instead of 2 Mhz. Working on 10 Mhz.
- Usable at high pressure, the limit is around 20mm. Hg due to
mean free path limitations.
- Filters have been built and developed. Resolution and peak
shape is being improved but already approaching that of currently
- A cold cathode source that can be produced on a substrate is
under development, i.e. a totally integrated MFS Mass Spec..
February 20, 2000
"...We are still very active on this project and have a paper in JVST B coming
out in March/April 2001 and a further talk at the IVC in San Francisco later
this year....." e-mail from Dr. Steve Taylor"
An MS Word document on "The World's Smallest Mass Spectrometer" may be
- The University of Liverpool Department
of Electrical Engineering and Electronics
Look for 'Si & Si/SiGe MOS Devices Utilising Low Temperature
SiO2 Insulators' under 'Solid State Electronics Research
- Micropower Impulse Radar developed at Lawrence
Livermore National Laboratory (LLNL). The MIR is a similar concept
to the 'Mass spectrometer on a Chip' mentioned above but is at a
higher state of development. A portable, very low cost mine
detector is under development in addition to some existing
Secondary Ion Mass Spectrometry (SIMS) Home Page is a new,
interactive site with a growing number of user's tips and
- Spettrometria di Massa di Ioni Secondari || University of Padova
Physics Department (In Italian)
(Secondary Ion Mass Spectrometry)
Copy and paste http://www.padova.infm.it/sims/simsp1 and try the
Translation Service if you don't speak Italian.
- Stanford Research
Systems RGA page includes a free downloadable demo. We bought
an RGA100 some time ago and had the unit up and running in a very
A typical RGA100 analog scan from a small, lightly baked vacuum
systm in our lab is here (38 kb jpeg)
Base Peak "The Web's Most Comprehensive Mass Spectrometry
Resource" , edited by Kemit Murray.