Model Magnet for the Proposed Superconducting Cyclotron at the University of Milan
A project for a superconducting cyclotron for heavy ions has been under study for a couple of years at the Cyclotron Laboratory of the University of Milan. The machine is conceived as a booster for a 16 MV Tandem to be installed at the Laboratories of Legnaro (Padua) of the Italian National Institute for Nuclear Physics (INFN). The K design value is approximately 540, thus allowing maximum energies between approximately 55 MeV/nucleon and approximately 14 MeV/nucleon for light and heavy ions respectively. Pole diameter is 1.8 m and maximum average field should be around 41 Kgauss, to be obtained by a total of 6.5 x 10/sup 6/ Aturns in the superconducting coils. At present a three spiral sector polar configuration is envisaged, with a 7 cm hill gap and 70 cm valley gap. Three dees, in the valleys, should provide a peak accelerating voltage of 100 kV, allowing a 3rd or 9th harmonic operation. While funding for the machine is still under discussion, a program centered upon the construction of a superconducting model magnet and a full scale rf model was started in 1976. The design features of the model magnet, whose construction is now completed, are reported.
Injection Studies for the K=800 Superconducting Cyclotron at M.S.U.
us recall that anticipated maximum beam energies are between 200 MeV/n and 50 MeV/n for fully stripped light ions and heavy ions (uranium) respectively. Minimum energies for the same extreme cases are 50 MeV/n and 5 MeV/n. Operating center field values are between 30 kG and 47 kG, and Z/A values of accelerated particles range from 0.1 to 0.5. Focusing and bending requirements lead to a 41" pole radius machine, and a three sector geometry, having 46 wide hills, with an unusually tight spiral, i.e. with a constant of 1/13 rad/inch.
Evaluation and Control of Collapsible Soils
Some compacted soils wetted under certain conditions of compaction and loading may exhibit additional settlement (collapse). To investigate the effect of the soil type, compaction water content, initial dry unit weight and applied pressure at wetting on collapse potential, 138 single‐oedometer tests were conducted on eight different soils. The results indicate that well‐graded soils tend to collapse more than poorly graded ones under similar conditions. Furthermore, collapse potential decreases with an increase in (1) The difference between the sand and clay percentages; (2) compaction water content; and (3) initial dry unit weight, while it increases with pressure at wetting. A multiple regression analysis was performed on the laboratory results to provide a collapse‐predictive model that was substantiated by data reported by several researchers. A chart is presented to estimate (1) The collapse potential of soils under various conditions; and (2) the critical water content beyond which no collapse is ex...