Robert Beringer

Mercury Vapor Jet Target and Stripper

A supersonic mercury vapor jet has been developed for use in stripping electrons from a beam of heavy ions. The required surface densities (2 to 20 μg/cm2) were obtained with the apparatus described. The increase in pressure caused by the jet was less than 3×10−7 mm Hg at the end of a 10‐in. beam tube.

A Magnetic Solenoid Electron Transporter

A magnetic solenoid electron transporter has been constructed to investigate conversion electrons produced in a target by the bombardment of heavy‐ion beams. It measures 32 cm in diameter, 124 cm in length, and weighs approximately 290 kg. The target is located at the center of the magnet so that the emitted electrons can be transported toward either end and their energies measured in Si(Li) counters. The energy resolution (for the 624 keV line of 137Cs) and the over‐all detection efficiency (for the energy range between 500 and 1200 keV) have been determined to be 6.9±0.2 keV and 6.0±0.4% for a 110 mm2 counter, and 22.0±0.9 keV and 16.0±1.1% for a 500 mm2 counter. This distortion of the energy spectrum for the same energy range is less than 7%.

Coincidence‐Counting System of High Resolution

A coincidence counting apparatus of high resolution is described. It employs proportional counters whose amplified pulses trigger blocking‐oscillators to give artificial pulses which are used in the coincidence discriminator. A continuously variable time delay is provided in one of the amplifier channels for determining the resolving time and for studying delayed coincidences. Under favorable conditions the passage of an ionizing particle through a counter can be determined to within an uncertainty of about 10−8 sec.

Gas Stripper for a Heavy‐Ion Linear Accelerator

A differentially pumped gas stripper for use in a heavyion linear accelerator is described. The stripping gases, air, oxygen, and argon, give the same stripping efficiency for ions in the range boron to neon for those charge states used in the accelerator. (C.E.S.)

An Overview of Heavy Ion Acceleration

The title of this talk, An Overview of Heavy Ion Acceleration, is a phrase which I must have approved some months ago but which seemed much too formidable a few weeks ago when I thought about the talk, and gave me an even better than usual excuse to delay preparing it. When this defense mechanism was finally running down last weekend I happened to be reading the new Harpers and was struck with a comforting idea. If Norman Mailer can summarize the Apollo Program and Womens Lib in one year then I can deal with heavy-ion acceleration if I follow his scenario. This, as I see it, is to firmly present your credentials and be as personally audacious as the subject permits.