Spring CleaningJuly 29, 2008
Yes, it’s mid-summer now, but “spring cleaning” is better done late than never! With work gearing up on the Carl’s Sr. fusor project and the requisite demands on my space and funds, I’m parting with some loot that will probably be more useful to someone else. Call 505-412-3277 or email firstname.lastname@example.org with questions or counter-offers. I accept PayPal at my email address.
- High voltage vacuum feedthroughs
- Vacuum valves
- Foreline trap
- NIM modules
- Radiation detectors
- High-power semiconductors
- High voltage capacitors
- Other stuff
High voltage vacuum feedthroughs: The large fluted ceramic feedthrough at left is mounted in an 8″ ConFlat flange and is easily capable of 100 kV in air-insulated service. There is no lead passing down the axis of the insulator; you’d have to supply your own. The “hot” end of the insulator contains a 1 1/3″ rotatable ConFlat on a hollow tube, which as the photo shows has been bent off-axis. 8″ flange knife edge is in good condition. Exterior of fluted insulator has some gummy residues that are soluble in acetone. Suggested price: $250.
The small ceramic feedthrough at right is probably vacuum-rated, but I don’t know for sure. The fluted side would be rated in the neighborhood of 30 kV in air. A solid piece of steel threadstock passes down the axis. Flange looks to be a custom elastomer seal (of which this is the female side). Suggested price: $25
Middle: KF-25 bellows-sealed stainless Key valve in good used condition. Suggested price: $40
Right: a brand-new, never-used MKS bellows-sealed stainless right-angle valve with rotatable 2-3/4″ ConFlat flanges. Heck, I even have the manufacturer’s original bag that this came in, it’s that fresh! Suggested price: $150
Foreline trap from MDC. KF-25 flanges, stainless steel construction. Comes with a full charge of 13X molecular sieve from Kurt Lesker (you might want to change it though). No heater supplied. Suggested price: $40
NIM stuff: I have an Ortec Model 452 spectroscopy amplifier and an Ortec Model 929 high voltage supply. Both are working, although the 929 has no side panels and the 453 amp is missing a 4-40 screw from one of its side panels. The 452 is suitable for general-purpose linear amplification and pulse shaping for radiation measurements. The 929 HV supply is +/- 10 kV and the polarity can be internally switched. $30 each.
Brand-new Hamamatsu photomultiplier tubes! Here’s a good deal for those folks wanting to build miniature scintillation detectors. These are 10-stage / 12 pin 3/4″ (19 mm) PMTs, brand-new in the box. The tube is a #6813341. I don’t know if an alternate “R” number is associated with these or not, but they share the same pinout as the R1450 and probably behave similarly. $20 each or $70 for all four.
Scintillation detector for prospecting: This Bicron 2M1/2 NaI(Tl) unit has been a constant companion on uranium collecting trips for many years. It has taken a beating physically in the field. Therefore, I doubt it would be any good for gamma spectroscopy, but it still works fine in its intended application. This detector comes with a socket assembly, made by George Dowell (K0FF). The dynode resistors are 10M each. Connector is BNC. The detector operates from ~1 kV on a Ludlum 3 ratemeter. $50
Victoreen 592B ion chamber ratemeter: an oldie but goodie, in working order. Requires a number of 22.5-volt batteries for chamber bias (included, have charge, but not new). Physically in decent shape. Last calibrated in 1992, according to sticker on side. Converted to use 1.5-volt alkaline batteries for the meter circuit in 2002 by Richard Hull. Measures exposure from 1-1000 mR / hr in three ranges. User must keep the desiccant packs inside dry. $60
High-power semiconductors: Powerex CM400HA-34H IGBT, CM300HA-24H IGBT, ND4414180 dual-diode block, and LS4414300P diode block. These parts came from a high-power switching circuit in a monstrous Crymer HV supply. Should be attractive to folks building switch circuits entailing hundreds of amps and thousands of volts. $20 each.
The small crucible is alumina and holds about 20 ml. $10
Voltage multiplier from x-ray power supply: Each of the big caps is rated 0.035 μF at 10 kVDC. Also, there are a plethora of nice high-voltage fast rectifiers on this board. Output voltage was intended to be 80 kV, according to some script on the board. Requires high frequency, high voltage AC to operate correctly. I recall checking the unit out a few years ago and found that it was functional. However, it is designed to operate under oil at 80 kV to eliminate corona and sparking. $25
High voltage transformer: salvaged from a large Universal Voltronics supply, this transformer seems to produce about 20 kV from an input of 240 VAC. It must be operated under oil. Likely capable of at least 1 kVA. Some rust is evident on parts of the core. $30. Remember, this is heavy!