Beam DynamicsMolecular Beam Skimmers

 

CUSTOM SKIMMERS - Please email or call to determine availability.

We are interested in a custom skimmer design. Do you provide design assistance?

No, we do not provide design assistance other than suggestions to ensure Beam can make the desired skimmer. We will undertake the production of a custom skimmer based only on drawings the customer provides. The drawings must be adequate for the programming of a lathe in order to cut the mandrel used for electroforming. This means the A, B, C, and D dimensions on our specifications page are supplied by the customer, as well as the wall geometry (straight or curved).

For any design, we recommend that a small radius be added where the wall of the cone meets the brim. This provides strength and helps prevent cracking at the joint.

Curved or straight walls can be chosen for the design. Curved designs need to begin with straight walls of 3mm to 5mm from the apex and then a radius can begin. The customer should specify the radius desired or specify a “best fit” relative to desired outside diameter and brim width.

The first shop drawing is included in the cost of a new custom skimmer mandrel. Any revisions will require additional drawings and additional charges.

Your web site includes drawings of Model 1 and Model 2 skimmers. Do you have drawings of the custom models offered?

Yes we do, but not in electronic form. We will fax drawings upon request but to help visualize the shapes, Models 1, 2, 5.1, 7.0, and 10.2 have curved sides while the balance are straight sided.

Could you help me understand the designation system used for your skimmers?

The Model 1 and Model 2 skimmers are our standard models. The balance of our skimmers’ designations refers to the length of the skimmer in mm from base to apex prior to machining. This is dimension A on the drawings and the specifications tables.

We’ve been using an old skimmer model in our lab and need to replace it. The designation is a combination of letters and numbers (e.g., UR-N2 or KFAJ-1) but there is nothing similar on your web site.

These are older designations for our skimmers, all of which were converted to the number system discussed above. We can convert to the current designation from the old style naming, or if need be, from measuring the old skimmer.

Does Beam produce replacement skimmers/nozzles for OEM mass spectrometers?

Yes. Beam supplies certain manufacturers with skimmers or nozzles for their equipment. For example, Vestec incorporated a Beam nozzle and two skimmers into their Thermospray ion source for a mass spectrometer. The Beam products were designated AC-1 at the time and are now called Model 10.2. We maintain an inventory of replacements for these parts as well as certain other manufacturers. Please inquire as to availability.

Can Beam produce tapered cone walls? Can Beam produce skimmers with brim thickness that is different than the wall thickness?

  Our skimmers are produced using electroforming. The process produces relatively uniform thickness in the walls and an identical thickness for the brim. Other than the machining of the orifice edge, the thicknesses are uniform throughout the skimmer.

Does Beam produce skimmers with different orifices sizes than those listed?

Yes, we can produce skimmers with dimensions other than those listed, subject to our normal size tolerances. For example, we could produce a skimmer with a 0.35mm orifice if desired. The price would be interpolated between the 0.3 and 0.4 prices, plus the set up charge.

Can Beam produce skimmers with very small orifice sizes?

Yes, but the minimum size orifice depends greatly on the included angle at the orifice. For example, we can produce Model 1 or Model 2 skimmers with a 0.1mm orifice. Other narrow apex angle models could also be made with small orifice sizes. The reverse is also true. The Model 10.0 model with its 90° included angle cannot be produced with an orifice size smaller than about 0.35 to 0.40mm.

We would like to use a Model 1 skimmer but with an outside diameter of 21mm rather than the listed size of 22.2mm. Can you produce this for us by reducing the brim width?  

No. All skimmer machining is done on the same mandrel that was used for the electroplating and the finished dimensions cannot be different than the mandrel.

Changing any dimension of height, included angle, outside diameter or brim width requires the fabrication of a new mandrel.

Can Beam produce a skimmer with a narrower included angle than any shown on your dimensions page?

Yes we can but it is expensive. The mandrel tip can break off during fabrication and the electroplating process is quite difficult. Please inquire regarding your design.

We plan to mount our skimmer using holes drilled through the brim. Would Beam provide skimmers with the appropriate holes?  

We prefer not to do any additional machining operations after the completion of the skimmer.  

Can Beam produce a skimmer from a refractory material?  

Beam sourced a supplier who would form tungsten cones for us, but at a very high cost. In addition, although our machinist has experience working with tungsten, there is no certainty that sharp enough orifice edges could be produced. Thus we would undertake the production of a tungsten skimmer only if the process were fully funded by the customer, despite the results.  

We have not and likely will not explore ceramics, molybdenum or any other materials.

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