The intensity and polarization of solar radio bursts at 9400, 3750, 2000, and 1000 Mc/s have been continuously observed since 1957 July. At 3750 Mc/s, the linearly polarized components were also measured during 4 months from 1957 October till 1958 January [1]. The analysis of observations to 1958 May reveals the following points:1. Many bursts at these frequencies show a difference in the intensity of two circularly polarized components. Frequency distributions of maximum degree of polarization of bursts are shown in Fig. 1, where weak bursts are excluded to reduce errors. At 3750, 2000, and 1000 Mc/s, particularly at 3750 Mc/s, the bursts of small degree of polarization are predominant. Circularly polarized bursts are occasionally observed at 2000 and 1000 Mc/s, but at higher frequencies the degree of polarization is usually less than 50 per cent.2. At 3750 Mc/s, no linearly polarized components could be detected in 117 bursts for a bandwidth of 10 Mc/s. The burst at this frequency is usually composed of a small degree of circularly polarized component and a randomly polarized one.3. Sometimes the sense of polarization varies with frequency. An example is shown in Fig. 2. On this occasion, the degree of polarization is small at 3750 Mc/s and the sense of polarization reverses between 2000 and 3750 Mc/s. Roughly grouped in Table I are 129 bursts simultaneously observed at four frequencies. The reversal of sense was found in 64 per cent of such bursts. Sometimes the sense of polarization varies with time, as may be found in our monthly report. Some of such phenomena may be interpreted by the motion of the source from the preceding part of a bipolar spot group to the following one or vice versa [4].4. In Fig. 3, the bursts associated with flares are classified in three types as regards the sense of polarization, and they are allocated to each of four quadrants on the solar disk according to the position of the flares. At higher frequencies, the sense of polarization seems to correlate with the position of the source as in the case of S component [2, 3]. A precise distribution map at 9400 Mc/s is shown in Fig. 4.
Collimated proton beams from magnetized near-critical plasmas