Relative luminosity measurement of the LHC with the ATLAS forward calorimeter
- Afonin, A. et al
- arXiv:1005.17840036327
 | Schematic layout of the experimental setup of the high luminositytest beam. The beam direction is from left to right. See text for details. |
 | Left: Channel layout during the April 2008 data taking run. Channels surrounded by circles were connected to the additional measurement device. Channels crossed out were not operational during the April run. Right: The FCALchick used in the Protvino test beams. The copper absorber matrix holds the rods with signal pins. Some of the rods are not installed. Also visible is thecooling loop for liquid-nitrogen cooling. |
 | Left: Channel layout during the April 2008 data taking run. Channels surrounded by circles were connected to the additional measurement device. Channels crossed out were not operational during the April run. Right: The FCALchick used in the Protvino test beams. The copper absorber matrix holds the rods with signal pins. Some of the rods are not installed. Also visible is thecooling loop for liquid-nitrogen cooling. |
 | Device for the additional independent measurement of the HV current. The four 24\,bit ADCs for the four HV current readout channels of the FCALchick are connected to a microcontroller to process their data and to add a timestamp from the real time clock to each measurement. The readout frequency is \unit{10}{$Hz$} per channel and theresolution is \unit{$1.2$}{\nano\ampere} per bit. |
 | Measurements of the HV currents for one spill taken during run 230 for one of the four readout channels. Upward pointing triangles indicate measurements assigned to a spill. Downward pointing triangles correspond to background measurements between the spills. The horizontal line shows the threshold to separate the spillsfrom background. |
 | Ratios of HV currents between channel\,1 and channel\,0 in the left plot and channel\,1 and channel\,2 in the right plot for runs 230, 240-244. For each channel the integrated HV current over one spill is used tocalculate the ratios. \\ |
 | Ratios of HV currents between channel\,1 and channel\,0 in the left plot and channel\,1 and channel\,2 in the right plot for runs 230, 240-244. For each channel the integrated HV current over one spill is used tocalculate the ratios. \\ |
 | Measured HV current summed over the channels 0, 1, and 2 vs. beam intensity compared to a non-linear fit for period A (runs 230, 240, 241) in the top plot, a magnified view of run 230 in the middle plot, and period B (runs 242-244) in the bottom plot. |
 | Measured HV current summed over the channels 0, 1, and 2 vs. beam intensity compared to a non-linear fit for period A (runs 230, 240, 241) in the top plot, a magnified view of run 230 in the middle plot, and period B (runs 242-244) in the bottom plot. |
 | Measured HV current summed over the channels 0, 1, and 2 vs. beam intensity compared to a non-linear fit for period A (runs 230, 240, 241) in the top plot, a magnified view of run 230 in the middle plot, and period B (runs 242-244) in the bottom plot. |
 | Comparison of the ISEG internal measurements of the HV current and the HV current measured by the external measurement device for runs 211-223on a spill-by-spill basis. |