Liquid Scintillation Cell

[George Schmermund]

The liquid scintillation cocktail / spooled and corrugated silver foil cell (Schmermund Cell for short) is making some progress in the areas of uniformity, ease of assembly, and reduced cost. I've roll milled some half dollar pieces and it's now easy to get a rectangular shape with square corners and uniform dimensions that measure 1" x 12". The thickness is ~3 mils. This leaves little guess work about the surface area and weight. Those who don't have roll mills can buy the foil from suppliers and it is easily cut to size with household scissors. I use this corrugator to build the spacer foil: eBay # 300487910805.
The seller's claim that it is all steel is a stretch (pun) because mine came with aluminum rollers. It still works great, though.

The purpose of this post is just to illustrate the original parts used to construct the first cell. As stated in a previous thread, the PET container is: eBay # 250810955009, and the LSC is Ecolume. The parts shown are prototypes used for fit testing. After a quick Google patent search, it is evident that the novelty of this cell is the transparency of the LSC vs. the amount of Ag surface area and mass that can be activated and detected using the corrugation and spooling method.

The foil shown is 10 mil aluminum flashing which is available in any hardware store. If your going to try and build one of these cells I recommend that you practice with the Al flashing. It will get expensive if you practice with Ag foil.

A new and improved cell that I'm experimenting with now uses machined plastic for cells. I'll make finished cells available for sale when the testing is done. Otherwise, the eBay containers previously listed can be purchased from the supplier very cheaply.

[Carl Willis]

The corrugator is a clever and reproducible approach to distributing a silver foil in a favorable geometry into liquid scintillator. I had no idea such tools existed. Should be useful to make any number of other things too, such as custom heatsinks.

Nice addition to an interesting project.

-Carl

[George Schmermund]

Carl - Speaking of trick hand tools, here's another one that I've found to be very useful: eBay # 300630758455. I use it to make rings of brazing alloy that can be shaped to fit the job. Just make the shape and flux it into place. No more poking the parts with a stick of brazing wire to see if the parts are hot enough. This method makes very clean and strong joints. The tool will pay for itself by not wasting expensive silver brazing alloy. Works great for making small parts with SS welding rod and the like, too. Pliers can't get even close to the smooth bends this tool will make.

Jeweler's tools are a windfall of specialty stuff. Check out: http://www.riogrande.com/

[Richard Hester]

Micro-Mark ( micromark.com ) is another good suppplier for bitty/specialized tools of all sorts.

[Richard Hull]

Silver brazing paste, combo flux and silver solder powder, is among the finest ways to apply silver solder for flawlessly clean work via "reflow" on any tiny or small work pieces and is sold and used by jewelers and myself. The Rio Grade URL given will have this. I get some of my supplies from them on occasion.

Richard Hull