Figure 2: from Dust in accelerator vacuum systems
The beam loss monitor count ratio N i,j = R i,j /R i−1,j reveals the influence of dust particles moving longitudinally around the HERA electron ring. The grayscale corresponds to a range 0.5...3 in N i,j at 12 GeV, where 1 represents background (no change). The ratios are plotted over the (i, j)-plane of BLM monitor numbers j = 1. .. 214 for the entire machine against time t i. Current in mA, energy 12 GeV and lifetime in h are shown on an extended scale
