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The 500 MeV first stage of an eventual two stage superconducting cyclotron system is in the final year of its construction phase. Major design features of the overall coupled system and construction status of the 500 MeV first stage cyclotron are reviewed.

As a whole, we believe that, as far as magnetic field properties are concerned, the following conclusions can be drawn with a large degree of assurance: i) azimuthal field modulation, as calculated from any saturated pole tip geometry, agrees with data to such an extent that this method can safely be used to predict harmonic amplitudes and phases; ii) absolute values of the average magnetic field can be predicted, even with a rather rough approximation, to within ± 1.%, at least in the range of fields B ? 25 kG where pole iron is largely saturated. This holds for inner radii fields and fri ngi ng fi el ds as wel 1; iii) more refined and time-consuming calculations can probably trim down these errors to a few parts per thousand, although, in our belief, with little more advantage from the point of view of a cyclotron early design. As quoted above, all magnetic field measurements stopped in January 1978. They will resume only if the cyclotron will be built, this time with the precise purpose of designing the final iron geometry of the machine. We believe that the availability of the model will enable us to shorten considerably the time needed to define, down to the very last details, the overall structure of the cyclotron.

A method is described for the production of large quantities of 123 I by exciting a ( p , 2 n ) reaction on enriched 124 Te targets. Results are presented for the relevant excitation functions. The irradiation technique and the chemical processes used in the separation of 123 I and the recovery of the target material are described in some detail.

The results of an extensive magnetic field mapping of the K-500 cyclotron under construction at M.S.U., covering the entire operating range of the machine, are reported. The data are analyzed in detail, and a comparison with the theoretical calculations used in designing the cyclotron is carried out. This comparison allows one to draw some general conclusions on the reliability of the theoretical model and its implications for superconducting cyclotron design.

Design work on the proposed K=800, KF= 400, superconducting cyclotron at MSU has progressed to the point where overall machine characteristics are firmly established. The main purpose1 of the machine is to serve as a booster for the K=500 cyclotron, now under construction. In this respect, let us recall that the design goal is to achieve maximum beam energies of 200 MeV/n for fully stripped light ions, and typically 30-40 MeV/n for heavy ions like uranium. Energy variability down to about 50 MeV/n and 4-5 MeV/n, again for light and heavy ions respectively, is also required to ensure some overlap with beam energies delivered by the K = 500 in stand-alone mode.

In connection with the superconducting cyclotron program at MSU a feasibility study of axial injection, aimed mainly at the K-800 cyclotron, has been carried out. The results encompass all major aspects of a working system, i.e. center region, injection trajectories and phase space matching. It is shown that axial injection is indeed feasible, although problems exist not ordinarily encountered in conventional AVF cyclotrons. The possible solutions and limitations are presented and discussed in detail.

The production of123I from enriched124Te is described. Preliminary experiments on a distillation separation of iodine from the Te target have been performed and the method seems promising in comparison to the time-consuming chemical separation technique.

The expected final characteristics of the magnetic field of the K-500 cyclotron at MSU are presented, together with the procedure used to properly shape and trim the field. The equilibrium orbits' properties of a number of representative ions are also given and discussed in detail.

The final design features of the extraction system for the K-500 cyclotron under construction at MSU are presented. The resulting cyclotron performance for a number of typical ions are reviewed and the expected extracted beam phase space characteristics are also discussed.

Angular distributions for six triton groups, produced in the 15 N( 3 He, t) 15 O reaction, have been studied in the incident energy range 16.5–37.7 MeV. Data on 3 He elastic and inelastic scattering have been also collected. Optical model parameters have been deduced; the ambiguities in the geometries, strengths and in the energy dependence seem to be correlated. Macroscopic calculations give a satisfactory description to the isobaric analog state transition by using a complex symmetry potential; a large energy dependence of the surface imaginary term is required. A microscopic analysis is also given. Evidence for the need of a tensor term in the effective interaction has been found. The energy dependence, of exponential type, seems to be similar for all the isospin-dependent terms of the microscopic effective interaction.

A review is given on the use of the Milan Cyclotron in trace element analysis via nuclear activation and X-ray fluorescence and in radioisotope production for medical and biological uses.

A fixed frequency, fixed energy Thomas cyclotron is presently under construction at the University of Milan. With a pole diameter of 166 cm, the planned energy is 45 MeV for protons; magnet winding and d.c. power supply are however rated to stand at least a 20 % increase in energy. Model studies of the magnet field and r.f. resonator have been carried out to test the cyclotron design. Adjustment of the field to meet the isochronism requirement will be entrusted to contouring and shimming of the poletips, with only comparatively minor corrections left to coils. Acceleration of polarized protons is proposed, and work is in progress on a polarized proton source. The assembling of the cyclotron magnet in its final location is due to begin soon, and the tentative date for the completion of the machine is the end of 1963.

The characteristics of the proton beam extracted from the Milan AVF cyclotron by H- ion stripping have been studied. Quality and phase measurements were made in an external beam which was obtained without any geometrical definition of the internal H- beam path.

Measurements of electron-capture cross-sections by fast protons in N2, O2 and Ar have been made in the energy range from 25 to 38 MeV, by using the variable-energy proton beam of the Milan cyclotron. The cross-section values were determined with an overall accuracy of ±12%. The results obtained, which extend to higher energies the range of the previous experimental data, are compared with published theoretical estimates, and a practical formula for the calculation of the cross-sections at high energies is proposed.

We describe the characteristics of a manometer for absolute pressure measurements of gases in open vessels, and under steady flow conditions. The analysis of the instrument's performance is carried out in some detail and shows that a precision of 1.2% in the pressure range between 10 −3 and 10 −2 torr has been obtained.

This paper presents an updated status report on the Superconducting Cyclotron, under construction at the University of Milan during the past two years, with funding chiefly provided by the Italian National Institute for Nuclear Physics. The cyclotron is designed for a K of 800 and a K /SUB FOC/ of 200 and thus yields maximum energies of 100 MeV/n for fully stripped light ions and 20 MeV/n for uranium and other heavy ions. The pole radius is 90 cm with three sectors having an average spiral constant of 1/45.7 rad/cm. The average magnetic field will span between 22 and 48 K Gauss with a corresponding R.F. frequency range between 15 and 48 MHz. The anticipated peak dee voltage is 100 KV with harmonic operation from h = 1 to h = 4. The operating modes include the use of an internal PIG source, injection from a 16 MV tandem, and axial injection from an external ion source. This paper presents the design parameters and outlines the progress made so far.

The preliminary extraction scheme described here does not seem, in principle, to offer any major obstacles. Further development should go towards: i) minimizing the problem of adapting the contour of deflectors to the trajectories of different ions, given the rather different orbits scalloping at high and low magnetic fields. ii) minimize the range of movements required for the extraction elements. iii) verify the possihility of insertiont of a third deflector, iiii) verify the possibility of an essentially constant,fixed, gradient for the magnetic channel, in which case a passive channel could be adopted. Work on these issues is in progress, and will be completed as soon as magnetic field data from the 1:6 scale model are available.

The K500 and K800 cyclotrons at the National Superconducting Cyclotron Laboratory must be joined by a beamline which matches the emittance of the K500 to the acceptance of the K800. This paper describes the optical design of that beamline, with particular emphasis on the conceptual design process. Specific optical constraints are given along with the techniques used for meeting them. Beam diagnostics are also discussed. All magnets will be superconducting.

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.

K500 cyclotron, now near completion, although operation with an internal ion source is also anticipated. The energies will be 200 MeV/n for fully stripped light ions and up to 30 MeV/n for heavy ions, depending upon the available charge states from the K500. The parameters of the machine are listed in Table I. The main differences with respect to ref. 1' are: - the increase in pole radius from 41" to 42", - the increase in the hill gap from 2.5" to 3", - the increase in the hill width, at outer radii, from 49 to 51'. The rationale for these choices will be discussed later. The operating diagram in the (B,, Z/A) plane is shown in Fig. 1, all limits are indicated in a straightforward way.

This letter reports the experimental results of (p, p′) scattering, with polarized protons, on 18 O and the analysis for low-lying positive-parity states based on the rotational model. Values of β 2 = 0.37 ± 0.03 and of β 4 = 0.18 ± 0.04 are obtained.

Successful production of 203Pb radioisotope with the proton beam of the Milan AVF cyclotron has made possible to start a wide range research program on pathway and effects of lead pollution. Irradiation and radiochemical separation techniques are described in some detail together with the synthesis of 203Pb tetraethyl. Applications to environmental problems carried out so far include chemical biological and biochemical studies. Preliminary results and the relevant experimental details are reported concerning lead uptake by different biological systems, and the distribution of lead in the air.

In this paper we report on recent results obtained at the Milan AVF Cyclotron in the production and use of I123.

A new axial injection system for the 88-inch cyclotron has been constructed. It transports beams from external ion sources axially through the magnet yoke to the median plane of the cyclotron. The optical elements include a bending magnet, electric quadrupoles, and the magnetic field of the cyclotron. Beam monitoring is done with scanning wires. phosphor plates and Faraday cups.