Absolute Measurement of the Vertical Cosmic-Ray Muon Intensity near 1GeVcat 12°N

The absolute vertical cosmic-ray muon intensity at sea level at 12° N has been measured with a range spectrometer similar to that used by Allkofer et al. and by Jokisch. The integral intensity amounts to 6.86 × ${10}^{-3\mathrm{}}$ ${\mathrm{cm}}^{-2\mathrm{}}$ ${\mathrm{sr}}^{-1\mathrm{}}$ ${\sec }^{-1\mathrm{}}$ at 0.954 $\frac{\mathrm{GeV}}{c}$ which is 10.3% lower than that of Allkofer et al. and 10.6% higher than that of Rossi, generally used as the normalization point for muon spectra. Our results are in favor of experimental findings of Allkofer et al. The decrease in intensity may be explained in terms of the geomagnetic latitude effect.