Transmutation effects observed with heavy hydrogen

Extract

In our paper “Transmutation of Elements by Protons,”* we showed that the transformation of some of the light elements by protons could be conveniently studied by the use of comparatively low voltages—of the order of 100,000 volts—by generating an intense narrow beam of protons which fell on the target of small area of about 1 sq. cm. In the light of experience of the past year, the installation has been modified in several particulars and entirely reconstructed. By the addition of another 100,000-volt transformer in tandem and the use of appropriate condensers the D. C. voltage available has been raised from 200,000 to 400,000 volts. The main change, however, consists in the use of a horizontal instead of a vertical discharge tube. In place of glass, a corrugated porcelain wall bushing capable of withstanding high voltages has been used to insulate the positive electrode, while the earthed metal casing forming the negative electrode projects through a brick wall. The arrangement of the internal electrodes is, in general, similar to that used in the earlier apparatus. The oil cooling circulation has been improved as the electrodes cannot, now be cooled by radiation alone. As before a magnetic field is applied to sort out the various types of ions generated in the discharge tube. The use of the horizontal tube has many advantages, not only for assembling the controls at convenient points but also in the ease of handling the counting apparatus and absorbing screens. The new installation has worked smoothly and satisfactorily and we have been able to increase the number of disintegration particles available for study by a factor of 10 to 50. The thick brick wall acts as a complete screen for the X-radiation generated in the system.