Ion source maintenance on the MAT 253

1
Ion source maintenance on the MAT 253

• Disassembling the ion source
• First draft by Anthony L Michaud

2
Use the manual!

• This presentation is NOT a replacement for the
  manual. Use the manual as much as possible! This
  presentation is intended to make it a little
  easier to see what each part looks like and to
  add to the manual.
• Schematics for the ion source are provided in
  section 8 of the manual
• Print out all pages from 8-48 to 8-67
• Turn off the mass spectrometer first by shutting
  off the pumps using the switches on the
  instrument
• Once you are ready to start work on the
  instrument, turn off the mains switch behind the
  instrument to shut off all electronics (just
  ensuring that you dont get a 10KV zap)
• Note if you have other instruments connected to
  the MAT 253 (such as the TC/EA), they should be
  in a safe state before shutting off the
  electronics. If not, then run an extension cord
  from the deltaplus over to the device and connect
  it temporarily to the deltaplus.

3
Plan this out!!! Use a clean surface and draw
everything! Write down a step by step detailed
sequence of what you do!
Clean surface for all parts. Can draw on surface.
Very nice!
Outline of parts and description
Step by step detailed account of work
4
Remove cover plates

• Remove the screws mounting the source lead cover
  in place
• These are flat head screws, two each holding each
  cover half to the source and two more holding the
  cover pieces together

5
Remove the cover plates

• The cover plates are fairly tightly held in
  place. You may need to pry them off gently with a
  screw driver
• Underneath the cover are the source leads, each
  insulated with a teflon sheet

6
Remove the leads

• Warning! The mains should be OFF so that you
  dont risk getting shocked!
• Slide the teflon cover off of a lead
• Use a 1.5mm allen wrench to loosen the lead and
  then slide the lead connector off of the source
  feed through pin

7
Pin identification

• Use the schematic from page 8-54 of the manual to
  identify the pins
• Note that the manual does a poor job of
  identifying these so see the next slide for detail

8
Pin identification

• K/K- pins for the filament
• 1 Trap
• 2 Ionization housing (ion box)
• 3 extraction plate
• 4 empty nothing connected here
• 5 shield
• 6 lens (positioned opposite of the gas inlet)
• 7 lens (positioned on same side as gas inlet)
• 8 r-delfection
• 9 z-deflection (filament side)
• 10 z-deflection (trap side)
• 11 einzel lens
• 12 einzel lens (double check this)
• 13 halogen lights
• 14 halogen lights
• 15 halogen lights

9
Removing the source

• Use a 13mm wrench to loosen each bolt on the
  source
• Loosen bolts in a criss-cross fashion
• Initially, only loosen each bolt by about 1/8 of
  a turn so as to evenly loosen the entire source
• Hint leave one bolt on top and one on bottom for
  last so that you can support the source with one
  hand while removing these bolts with the other

10
Ion source
Einzel lens stack
Sulfur window

• Place the ion source on the stand (be sure that
  no weight is put on the feedthrough pins!!!)
• Observe the connections, plates, gas inlet,
  sulfur window, etc.

Gas inlet
Magnet over filament
11
Ion Source
Einzel lens stack
Sulfur window

• Note where leads are connect and what they are
  connected to

Gas inlet
Ceramic guide posts
Magnet over filament
12
Ion source
Einzel lens stack

• Turn the source and see the other leads

Trap side magnet
Gas inlet
Halogen bulbs
Steel mounting posts
13
Ion source
Einzel lens stack
Einzel lens lead
Sulfur window

• Observations

Exit slit
Filament side magnet
Trap side magnet
Ionization housing
14
Ion source
Einzel lens stack
Einzel lens lead
Einzel lens lead

• Observations

Trap side magnet
Filament side magnet
Filament leads
Gas inlet
15
Disconnect filament

• Use a flat head screw driver to disconnect the
  filament leads from the feedthrough post
• Then remove screws holding the filament magnet in
  place
• Finally, remove screws holding filament in place

16
Disconnect leads

• Use pliers (small ones) to retract each lead from
  the pin it is connected to
• DO NOT remove leads from the feedthrough pins on
  the source flange

17
Remove the source body

• After removing all of the leads, double check
  that they really are ALL disconnected
• Use a larger flat head screw driver to remove the
  two screws from the steel mounting posts (sorry,
  no picture)
• Remove the source body and place it gently onto a
  clean work surface

18
Remove Einzel lens leads

• Use the needle nose pliers to remove the leads
  from each einzel lens
• See manual, p 8-66, fig 8-12

19
Remove Ground Plates

• Remove the 4mm nuts and washers on top of the
  einzel lens stack
• Remove the top grounding plates (these are
  stamped 5 on the side facing the ionization
  housing)

20
Remove Einzel lenses

• Remove the outer ceramic spacer tube
• Note that groove in ceramic spacer is facing
  ionization housing
• Remove Einzel lenses (these are stamped 4 on
  the side facing the ionization housing)

21
Remove grounding plates

• Remove the second set of ceramics (narrow tube
  and shorter wide space)
• Note again that grooves in ceramics are facing
  ionization housing
• Remove the second pair of grounding plates
• Einzel lens stack is now completely removed

22
Remove magnet and trap

• Remove the magnet covering the trap (electron
  collector)
• Remove the trap

23
Loosen ceramic posts

• Note where the ceramic post protrude through the
  top (side opposite the ionization housing) of the
  ion source
• Use a small screw driver (if necessary) to loosen
  the threaded sleeves on the ceramic posts (these
  provide tension to hold pins in the bottom of the
  posts on the ion box side)
• Use pliers to remove the pins in the bottom of
  the ceramic posts

24
Dissasembly

• Slide the ceramic posts out about 1 cm at a time
  in order to disassemble the ion source piece-wise

25
Put source on its side!

• Important Note The first time I took the source
  apart was not the best way to do it! Do not place
  the ion source in an upright position as I did in
  the top picture here. There is a quartz tube that
  transfers gas from the gas inlet to the
  ionization housing and it is VERY FRAGILE! I
  chipped mine by placing the source upright. Put
  the source on its side
• The steps that follow are given in the better
  order (not the order I followed the first time)

Fragile quartz tube
26
Remove gas inlet and ion box

• Remove the post holding the gas inlet
• Retract the fragile quartz tube from the
  ionization housing
• Remove the ionization housing

27
Ground plate and quartz spacer

• Remove the cover plate (stamped 9 on the side
  facing the ion box)
• Remove the narrow quartz spacer ring

28
Extraction plate and spacer

• Remove the extraction plate (stamped 8 on side
  facing ion box)
• Remove the quartz spacer ring (last item shown in
  Fig 8-10 of manual)

29
Shield and spacer

• Remove the shield (stamped 7 on side facing ion
  box)
• Remove quartz spacer

30
Lenses

• Remove lenses (two have circles)
• These are stamped 6 on side facing ion box
• Note the orientation of the lead pins on each
  lens one faces straight out and the other is at
  a 45 degree angle

31
Quartz spacer and r-deflection plate

• Remove the quartz spacer
• Remove the r-deflection plate (stamped 5 on
  side facing ion box)

32
Z-deflection and ground plates

• Remove quartz spacer
• Remove the assembly containing ground plates
  (these are connected by a U-shaped lead) and the
  z-defection plates
• Disassemble this assembly, take pictures, and
  improve this slide!

33
Remove exit slit

• Remove the exit slit from the source base

34
Replace halogen bulbs

• Replace the halogen bulbs
• Note they are cheap so you should replace them
  even if they look ok

35
Cleaning

• I only use a glass brush to remove all residues
  from the lenses. I have not cleaned the quartz
  spacers or ceramics. In general, quartz spacers
  can be cleaned by sonication in acetone.
• Be very careful about cleaning the ceramics. You
  should check on isogeochem and also with Thermo
  about heat-treatment to clean them if you think
  it is necessary

36
Improve this slideshow

• Upon the next ion source cleaning, many pictures
  should be taken and this slideshow should be
  improved.
• Add pictures of glass brush use
• Add pictures showing removal of ion source from
  steel mounting posts
• Add more