High-speed Support Improved in Latest Actuel Release (1.7) for the 9103 Picoammeter

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RBD has released Actuel version 1.7 for the 9103 Picoammeter, with improvements for high-speed data acquisition and (especially) data logging and graphing.

The latest version can be found here.

If you do not have a high-speed 9103 Picoammeter and are already running Actuel version 1.6, there no reason to download the latest version. However, high-speed users will find a number of improvements.


Oscilloscope emulation


Although Actuel was not designed to have an oscilloscope emulation (with features such as triggering), at higher speeds you can come close to emulating scope current monitoring.

In the Data Window, click the Show Options button and select “Last” from the Graph Options. You can scroll in increments as low as 0.1 second, but you can type in a smaller increment, such as “0.05” in order to display at higher resolution.

Last time option in Actuel
Using the “Last” time option in Actuel


(Note: The graph display options can get out of sync with data collection if you change and option when recording or after stopping and clearing data – it may be necessary to re-enter the value or reset recording. We’re working to make this smoother in the next version.)

For smoother real-time graphing, use standard-speed at 25 mS unless faster rates are needed

The 9103 can run as fast as 25 mS per sample in standard-speed mode, and 2 mS per sample in high-speed. In order to optimize faster data acquisition in high-speed mode, the 9103 collects 10 samples per message, as opposed to 1.

However, note that if you are collecting data at 25 mS in Standard-speed, your PC will be updated with new data every 25 mS. In High-speed, you’ll be updated every 250 mS.

For that reason, the Acutel software always collects data in standard-speed mode at 25 mS and above, regardless of the high-speed mode settings. It is recommended you do the same if you are writing your own software to control the 9103.

That also means that for real-time graphing, you may not want to sample at a rate of, for example, 24 mS, if you can achieve the same results at 25 mS. At faster rates, the delay in caused by receiving 10 samples per message is less noticeable, but it’s visible at rates of 20 mS- 25 mS if you are graphing only the latest points in relatively high resolution:

Actuel 25 mS Standard Speed

Actuel – 25 mS Standard Speed

Actuel 25 mS High Speed

Actuel – 24 mS High Speed

Removing and Installing Copper Gaskets On Vacuum Chambers

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If you are new to UHV vacuum chambers and how to create a seal using copper gaskets when mounting optics, this blog post has some useful tips.

In many cases, installing the copper gaskets that are used to seal flanges on UHV vacuum chambers is as simple as placing the copper gasket in the knife edge recess. If the flange is facing down, then the gasket can be placed on the optics part being installed and the gasket will stay in place.

But in cases where the flange is perpendicular to the floor, the gasket will not stay in place on its own because the gravitational constant will prevent the gasket from staying in place. In other words, the gasket will fall.

There are a few ways to install a gasket onto the flange. But first, you need to make sure you’ve removed the old gasket properly.

Removing Gaskets

When you remove the old gaskets, you want to be very careful not to nick the knife edge on the flange when removing the old copper gasket because a nicked knife edge often results in a vacuum leak. And, nicked knife edges are difficult and sometimes very expensive to repair.

Usually the gaskets will come off easily with a minimum amount of force. For those gaskets that are pressed in tightly and very hard to remove, I have found that using a long-nosed vice grips locking pliers works quite well.

6" long nose Vice Grip needle nose pliers

You can adjust the gap on the pliers so that it firmly clamps down on the gasket, then simply bend the pliers so that the leverage will pop the gasket off the flange. It works every time and most importantly, it follows the number one rule of flanges – protect the knife edge. You can use a screwdriver to pry up the edge of the gasket, but if the screwdriver slips, you risk damaging the knife edge.

Pry up gasket

Two resources for removing gaskets:

Removal of metal UHV gaskets; Journal of Vacuum Science and Technology 12, 654 (1975) https://doi.org/10.1116/1.568642 https://avs.scitation.org/doi/abs/10.1116/1.568642?journalCode=jvs

A UHV-Gasket Removal Tool; Published March 1, 1983 https://www.nist.gov/publications/uhv-gasket-removal-tool

Installing New Gaskets

Method 1: Gasket Clips

The first method is to use a gasket clip. Gasket clips hold the copper gasket to the flange via a spring action. They line up with the flange’s leak check groove and hold the gasket in an area that is just past the knife edge of the flange.

Gasket Clip

Here is a link to the gasket clips that Ideal Vac provides:

https://www.idealvac.com/Agilent-GC0275S-Conflat-Gasket-Clip-Set-Package-of-10/pp/P105418

Gasket clips work well most of the time. Sometimes they will not work due to geometry limitations with other nearby flanges or optics.

If you do not have gasket clips, there are some other ways to mount a copper gasket to a horizontal flange.

Method 2: Elongate the Gasket

The second method is to elongate the gasket. This works well for larger copper gaskets, such as those for 10-inch and 8-inch flanges. It works with smaller gaskets as well, but you will need to drop them from a higher distance from the floor.

For an 8-inch gasket, hold the gasket about 1 foot above the floor. Hard concrete floors work best. This technique will not work on carpet.

Hold the gasket

Drop the gasket on its edge and it will hit the floor and bounce back up. You need to catch it when it bounces back up. If you don’t catch it and it falls to the floor, that is OK. You will just need to clean the gasket off with some isopropanol or methanol.

It takes a little bit of practice to get the correct height from which you are dropping the gasket. But the general rule is that the smaller the gasket, the higher the height. I have used this technique on 10-inch to 4.5-inch gaskets with good results. 10-inch flange gaskets should be dropped from about 6 inches. 4.5-inch gaskets should be dropped from about 18 inches. 2.75-inch gaskets are more difficult as they are harder to deform than the larger gaskets.

When you insert the gasket into the flange, you need to press it into the knife edge recess. The slight elongation will act like a spring and the gasket will stay in place.

Method 3: Cellophane (Scotch) Tape

Which brings us to the third method for mounting copper gaskets – cellophane (Scotch) tape.

Scotch Tape

You can use Scotch tape to mount the gasket as long as the tape is just barely on the gasket. Since the tape is mounted outside the knife edge, then it is OK if any of the tape stays on the gasket because it will be on the air side of the knife edge.

The pictures below show the knife edge cuts on common gasket sizes. For most copper gaskets (2.75- to 10-inch flange sizes) the knife edge is approximately .100 inches from the outside edge of the gasket. For the very small 1.33” flange, it is .050 inches from the gasket’s outside edge.

Knife edges

The procedure is to place the tape to where it is barely on the gasket (outside the knife edge region) and then very lightly touch the flange. You can use 2 or 3 sections of tape as needed.

Tape on copper gasket
6 inch CF flange
Gasket with tape

Once you get the optics part mounted to the flange with just a few nuts or bolts to hold it in place, pull the tape straight up and away from the flange. Usually all of the tape will come out. But if any small piece of tape is left behind, it will not matter since it is on the air side of the knife edge and will not have an effect on the vacuum.

Rotate the flange slightly to make sure that the copper gasket is properly seated before you tighten the bolts.

And don’t forget that if you are up to air for awhile and need to cover a flange or optics component with aluminum foil, you should use a UHV foil such as All Foils. UHV foil does not have an oil coating on it like foil from the super market does.

https://www.allfoils.com/single-product/uhv-foil/

UHV aluminum foil

RBD Instruments provides copper gaskets for less than what most other vacuum supply companies charge. – https://rbdinstruments.com/phi/uhv-parts.html

New Ion Beam Profiler

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Idaho National Laboratory has development a new type of ion beam profiler that reconstructs the ion beam intensity in two dimensions with a single measurement device.

This technology is available for licensing.    More information can be found at this link –

Ion Beam Profiler

Companies interested in learning more about this licensing opportunity should contact Kala Majeti at td@inl.gov or by calling 248-877-8866