1548208 SzGeCERN 20220810222014.0 DOI 10.1088/1748-0221/8/06/P06001 oai:cds.cern.ch:1548208 cerncds:FULLTEXT cerncds:CERN:FULLTEXT cerncds:CERN arXiv oai:arXiv.org:1305.4592 Inspire 1234237 arXiv arXiv:1305.4592 physics.ins-det eng INSPIRE-00357120 Anderlini, L. INFN, Florence A new method based on noise counting to monitor the frontend electronics of the LHCb muon detector 2013 20 May 2013 15 p A new method has been developed to check the correct behaviour of the frontend electronics of the LHCb muon detector. This method is based on the measurement of the electronic noise rate at different thresholds of the frontend discriminator. The method was used to choose the optimal discriminator thresholds. A procedure based on this method was implemented in the detector control system and allowed the detection of a small percentage of frontend channels which had deteriorated. A Monte Carlo simulation has been performed to check the validity of the method. IOP A new method has been developed to check the correctbehaviour of the frontend electronics of the LHCb muon detector.This method is based on the measurement of the electronic noise rateat different thresholds of the front-end discriminator. The methodwas used to choose the optimal discriminator thresholds. Aprocedure based on this method was implemented in the detectorcontrol system and allowed the detection of a small percentage offront-end channels which had deteriorated. A Monte Carlo simulationhas been performed to check the validity of the method. A new method has been developed to check the correct behaviour of the frontend electronics of the LHCb muon detector. This method is based on the measurement of the electronic noise rate at different thresholds of the frontend discriminator. The method was used to choose the optimal discriminator thresholds. A procedure based on this method was implemented in the detector control system and allowed the detection of a small percentage of frontend channels which had deteriorated. A Monte Carlo simulation has been performed to check the validity of the method. arXiv CC-BY-3.0 publication CERN 2013 publication INSPIRE-PUBL-2013 arXiv Detectors and Experimental Techniques arXiv Particle Physics - Experiment ARTICLE CERN CERN LHC LHCb CERN LHC LHCb LANL EDS physics.ins-det LANL EDS hep-ex INSPIRE-00258635 Antunes Nobrega, R. INFN, Rome INSPIRE-00258110 Bonivento, W. INFN, Cagliari INSPIRE-00296124 Gruber, L. CERN INSPIRE-00259213 Kashchuk, A. St. Petersburg, INP INSPIRE-00296138 Levitskaya, O. St. Petersburg, INP INSPIRE-00259220 Maev, O. St. Petersburg, INP INSPIRE-00258664 Martellotti, G. INFN, Rome INSPIRE-00226158 Penso, G. INFN, Rome U. Rome La Sapienza (main) INSPIRE-00258670 Pinci, D. INFN, Rome INSPIRE-00028229 Sarti, A. U. Rome La Sapienza (main) Frascati INSPIRE-00260343 Schmidt, B. CERN P06001 JINST 8 2013 http://arxiv.org/pdf/1305.4592.pdf Preprint 2232117 17909 http://cds.cern.ch/record/1548208/files/figure_Cdet.png 00009 Dependence: a) of the bias voltage ($V_b$) and b) of the ENC, on the detector capacitance. Open (full) points refer to cathode (anode) readout. The error bars represent the r.m.s. of the distributions. 2232118 17773 http://cds.cern.ch/record/1548208/files/figure_sigmaR.png 00005 a) Counting rate of the discriminator as a function of its threshold. b) Same as in a) but presented with logarithmic-quadratic scales. 2232119 26229 http://cds.cern.ch/record/1548208/files/figure_discriminator2.png 00002 a): Noise counting rate of an ideal discriminator as a function of its threshold (continuous curve). With the CARIOCA discriminator the threshold values comprised in the shaded area cannot be set and the rate at zero threshold ($R_0$) cannot be measured. In the upper scale the DAC registers which set the thresholds are schematically reported. b): Typical experimental curve representing the noise counting rate of a CARIOCA discriminator as a function of the DAC registers. 2232120 31027 http://cds.cern.ch/record/1548208/files/figure_scatter_09-12.png 00011 a): Scatter plot of the ENC values measured on all the muon detector in the years 2009 and 2012. The channels which are far from the plot bisector were checked and repaired or replaced. Most of the points in the series indicated by an arrow correspond to CARIOCAs mounted on the same boards which were replaced. b): Distribution of the difference between the ENC measured in 2012 and 2009. 2232121 44099 http://cds.cern.ch/record/1548208/files/figure_signal.png 00003 a): A typical simulated noise signal. The points are the values calculated every 3 ns. b): Discrete Fourier transform of 10$^6$ consecutive noise values, corresponding to a time interval of 3~ms. The DFT values have been averaged on 0.7 MHz bins. 2232122 15798 http://cds.cern.ch/record/1548208/files/figure_sigmaV.png 00004 a): Distribution of the $2 \times 10^8$ values of the noise amplitude $V/A$ (equation~\protect \ref{sum}). In figure b) the same distribution is reported with logarithmic-quadratic scales. 2232123 51995 http://cds.cern.ch/record/1548208/files/figure_crosstime2.png 00006 Monte Carlo predictions for the distribution of the time intervals between two consecutive threshold crossing, for four different threshold values. The dashed curves represent the same distributions if the crossing times were completely uncorrelated. 2232124 9781 http://cds.cern.ch/record/1548208/files/figure_discriminator1.png 00001 Dependence of the threshold ($V_{thr}$) of the CARIOCA discriminator around zero on the DAC register units ($r.u.$). 2232125 28279 http://cds.cern.ch/record/1548208/files/figure_bias_enc2_M3R3_M5R4.png 00008 Distribution of: a) the bias voltage; b) the ENC measured for of all the reaudout channels of the region M3R3. c) and d): same as a) and b) for the readout channels belonging to region M5R4. \vspace*{5truemm} 2232126 11296 http://cds.cern.ch/record/1548208/files/figure_noisy.png 00012 Experimental threshold scanning for: a) a properly behaving front-end channel; b) a malfunctioning channel with an abnormal noise. 2232127 21249 http://cds.cern.ch/record/1548208/files/figure_amplifier.png 00000 a): Measured sensitivity of the amplifier. b): Measured gain $G$ of the amplifer for a sinusoidal signal as function of frequency~$f$. The curves are normalized to their maximum value. The rectangular approximation to the frequency spectrum of the amplifier gain, as used in the MC simulation, is indicated with the 3dB limits at 20 and 50 MHz. The lines are to guide the eye. In both figures the open (full) points refer to negative (positive) input polarity. 2232128 531420 http://cds.cern.ch/record/1548208/files/arXiv:1305.4592.pdf Preprint 2232129 36973 http://cds.cern.ch/record/1548208/files/figure_exp_sigma2.png 00007 a): Experimental threshold scan of a readout channel of region M3R3. In b) the right-arm of this distribution is represented with logarithmac-quadratics scales. The open point at zero threshold is the counting rate predicted by Rice theory and by the MC. The straight line is the best fit to the points (see text). c) and d): same as a) and b) for a readout channel belonging to region M5R4. The larger detector capacitance ($C_{det}$) results in a larger $\sigma$. n 201320 a2013 13 ARTICLE