Auger Electron Spectroscopy Tutorials

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RBD Instruments’ microCMA is an affordable compact Auger Electron Spectroscopy (AES) cylindrical mirror analyzer package which is small enough to add to existing vacuum chambers.  For applications which require elemental information on the top most mono layers of specimens, AES can be the perfect solution. More information…

Following are links to a variety of Auger Electron Spectroscopy tutorials which explain in detail the principles of AES, the instrumentation, and the applications.

Wellesley College AES  (pdf)

Eagle Analytical Labs AES Theory

Hong Kong City EDU AES (pdf)

University of Delaware AES (pdf)

Johns Hopkins University Principles of AES

Auger_Electron Spectroscopy (Powerpoint)

MicroCMA Sample Data (pdf)

microCMA

EMO box push button switches

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The EMO box (Emergency OFF) used on many PHI systems has switches that can become noisy, stick or fail to operate at all. These switches are used to turn on and off the card rack power, main electronics console power, vacuum console power, bakeout power and to turn off and reset all power.

Another very common issue is that the light bulbs in the switches tend to burn out on a yearly basis.  This blog post will describe where to get replacement parts for the EMO boxes.

The round red EMO button switch is still available but the original square push button switches that were produced by Cutler-Hammer (now Eaton) are very difficult to find. Honeywell equivalents are listed below.

There are two styles of EMO boxes.  The 32-005 style has a Bakeout switch and the other style has a Vacuum Console power switch.

EMO box
EMO box
32-005 EMO box
32-005 EMO box

Equivalent replacement switches produced by Honeywell are listed below.

EMO box switch
EMO box switch
EMO button McMaster-Carr PN 7403K42  
Main Power ON/Reset   Honeywell PN #: AML21CBA3AC
Allied Electronics Stock #: 70119090
Main Power / OFF Honeywell PN #: AML21CBA3AC
Allied Electronics Stock #: 70119090
Electronics  Console Power Honeywell PN #: AML21CBE2AD
Allied Electronics Stock #: 70119866
Vacuum Console Power Honeywell PN #: AML21CBE2AD
Allied Electronics Stock #: 70119866
Card rack power Honeywell PN #: AML21CBE2AD
Allied Electronics Stock #: 70119866
Bake Out Power Honeywell PN #: AML21CBE2AD
Allied Electronics Stock #: 70119866

Original lamp –

T1 3/4 Wedge lamp
T1 3/4 Wedge lamp

Lamp; Incandescent; T-1 3/4; Sub-Mini Wedge; 28V; 40mA; 0.3MSCP; 7000 Hrs

Manufacturer #: 85

Allied Stock #: 70013004

Recommended LED replacement lamp –

T1 3/4 LED wedge lamp
T1 3/4 LED wedge lamp

Lamp; LED; T-1 3/4; Sub-Mini Wedge; White; 28V; 40mA; 0.3MSCP; Lamp life 30,000 hours.

Manufacturer #: LED-24-T1.75 WEDGE-W Allied Stock #: 70012994

These LED lamps are more expensive but will last for almost 4 years compared to about 1 year for the regular tungsten lamps.

Mouser PN 560-LE-0509-01W is a white LED that would work for all of the switches and it costs less. Made by JKL Components https://www.mouser.com/datasheet/2/208/LE-0509-01-21680.pdf

Bonus – EMO box schematics are shown below

32-005 EMO box
32-005 EMO box
EMO box
EMO box

Infrared Bakeout Package

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Our new VB series bakeout packages are an easy way to remove water vapor from vacuum chambers. The UHV-compatible IRB-600 short wave infrared radiation emitter mounts on a standard 2.75”/70mm CF flange. The BC-3 controller uses thermocouple feedback to regulate the vacuum chamber temperature, controls the power to the IRB-600 emitter, and sets the total bakeout time. These are all the features that you would expect with a vacuum bakeout package.

What sets the VB series BC-3 apart from other bakeout controllers is the Vacuum Interlock feature. The Vacuum Interlock uses a Setpoint relay on your vacuum gauge controller to regulate the vacuum level in the chamber. For example, if your chamber has ion pumps, you can set your vacuum gauge controller Setpoint to 4 x 10-6 Torr which will turn off the heat to the chamber when the vacuum setpoint is reached.  Whether your chamber has ion pumps or a turbo pump, the Vacuum Interlock feature can be used to ensure that your pump does not get choked with water vapor.

Here is a link to a short video on the VB Series vacuum chamber bakeout package.

The BC-3 controller can drive two IRB-600 emitters, two heater tapes, or even one of each!

BC-3-Bake-Out-Controller
BC-3-Bake-Out-Controller

Infrared radiation(IR) heats the chamber from the inside out and is very effective compared to external radiant bakeout heaters. The thermal conductivity of stainless steel at 100° C is only 15 W/m K compared to 300 W/m K for copper at 100° C. Therefore, it takes a long time for external bakeout heaters to heat up the inside of the vacuum chamber surfaces. 

IR heats the internal surfaces of the vacuum chamber very quickly. Using internal IR heat even for a short time during the initial pump-down can have a noticeable effect on pumpdown times and base vacuum. To reach low UHV vacuum levels you need to bake for longer periods of time.

IRB-600 emitter
IRB-600 emitter

The short wave IR energy of the IRB-600 emitter drops off as a function of distance. The internal chamber surfaces that are closer to the emitter will become hotter than surfaces that are further away from the emitter. This effect is not precisely linear, but you do need to consider it with regards to thermocouple sensor placement on the chamber. Typically, the thermocouple sensor should be about 6-to-10 inches away from the IR-600 emitter. If you have two IRB-600 emitters on your chamber, place the thermocouple sensor at the midway point between the two emitters.

Once the thermocouple sensor has been placed, you can program the bakeout temperature setpoint. Typically, the bakeout temperature setpoint is programed 20° C-to-30° C lower than the temperature on the surfaces that are nearer to the IRB-600 emitter. If you would like the chamber to be 150° C near the IRB-600 emitter, program the bakeout temperature to 125° C. 

Before using the Vacuum Interlock feature, you need to program your vacuum gauge setpoint to the desired value. Typically, the vacuum setpoint is 3 or 4 x10-6 Torr for ion pumps and 5 x 10-4 Torr for turbo pumps. Then, simply turn the Vacuum Interlock switch on the BC-3 controller to On. If you would prefer to bake the chamber into the turbo pump before you turn on your vacuum gauge, then set the vacuum interlock switch to Off; the IRB-600 emitters will turn on and be regulated only by the vacuum chamber temperature.

In our shop we have a few vacuum chambers that come up to air practically every day, and some days more than once per day. We use the BC-3 with a single IRB-600 emitter and one 600 watt heating tape to effectively remove water vapor. If we know that we will be venting again later in the day, we turn on the BC-3 as soon as we start pumping down the chamber in order to take advantage of viscous flow and to let the turbo pump down the chamber for about 30 minutes. Then we turn off the BC-3 and start the ion pumps; the vacuum chamber will be down in the low 10-8 Torr range within a few hours. If we need a better vacuum, then we bake the chamber out for 8-to-10 hours over night. The following day the vacuum chamber will be in the 10-10 Torr range after the chamber cools down and also using a titanium sublimation pump. Not needing to remove cables and preamplifiers from the chamber is a big time-saver. We use the VB bakeout package practically every day and every time we do, we really appreciate how easy it is to bakeout a vacuum chamber with the BC-3 and IRB-600 compared to external heaters and bakeout blankets.

The BC-3 and IRB-600 are available in 120 VAC and 230 VAC configurations.

For more information on the VB series bakeout controller, visit our website at this link –

https://rbdinstruments.com/products/vb.html

No-bakeout-blankets-required
No-bakeout-blankets-required