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Schematic layout of the AHCAL prototype placed on a moving stage. The steel plates mounted on rods are shown rotated with respect to the beam that enters from the right hand side. The rack in the front houses the supply voltages, trigger electronics, and data acquisition system.
Schematic tile layout of a scintillator module for layers 1--30 (left) and a photograph of tiles in a module (right). The red dots indicate the position of the thermosensors.
Schematic tile layout of a scintillator module for layers 1--30 (left) and a photograph of tiles in a module (right). The red dots indicate the position of the thermosensors.
Schematic cross section of a cassette (not to scale).
Readout of $\rm 3~cm \times 3~cm ~(left), \rm 6~cm \times 6~cm$ (middle), and $\rm 12~cm \times 12~cm$ tiles (right) with WLS fibers and SiPMs.
Readout of $\rm 3~cm \times 3~cm ~(left), \rm 6~cm \times 6~cm$ (middle), and $\rm 12~cm \times 12~cm$ tiles (right) with WLS fibers and SiPMs.
Readout of $\rm 3~cm \times 3~cm ~(left), \rm 6~cm \times 6~cm$ (middle), and $\rm 12~cm \times 12~cm$ tiles (right) with WLS fibers and SiPMs.
A typical SiPM spectrum for low-intensity light (left) showing the pedestal in the first peak and up to eight fired pixels in the successive peaks. The response function for SiPMs of fired pixels versus input light (right). The curves are taken as a set of twenty measurements at increasing light intensities and can be fit with a sum of two exponential functions.
A typical SiPM spectrum for low-intensity light (left) showing the pedestal in the first peak and up to eight fired pixels in the successive peaks. The response function for SiPMs of fired pixels versus input light (right). The curves are taken as a set of twenty measurements at increasing light intensities and can be fit with a sum of two exponential functions.
The distribution of SiPM noise at half a MIP threshold (left), cross talk (middle), and current (right). Arrows show the maximum values on noise, cross talk and current permitted in the prototype.
The distribution of SiPM noise at half a MIP threshold (left), cross talk (middle), and current (right). Arrows show the maximum values on noise, cross talk and current permitted in the prototype.
The distribution of SiPM noise at half a MIP threshold (left), cross talk (middle), and current (right). Arrows show the maximum values on noise, cross talk and current permitted in the prototype.
Distributions of the relative variation of SiPM parameters (number of pixels per MIP, SiPM gain, SiPM response, SiPM efficiency, noise frequency and cross talk) for a 0.1~V change in bias voltage.
Light yield of 8100 scintillator tiles measured at ITEP on a test bench. For the prototype, tiles with a light yield closest to 15 pixels/MIP were selected.
Photograph of a fully assembled module.
Photograph of the wedges fixing the tiles inside a cassette (left) and photograph of the flexfoils used in a cassette (right).
Photograph of the wedges fixing the tiles inside a cassette (left) and photograph of the flexfoils used in a cassette (right).
Schematic view of the readout and data acquisition.
Block diagram of the ASIC chip.
Pulse shapes in the calibration mode (left) and the physics mode (right).
Pulse shapes in the calibration mode (left) and the physics mode (right).
Coupling diagram of the SiPM to the ASIC chip.
Schematic diagram (left) and photograph (right) of the ASIC chip.
Linearity measurements of preamplifier and shaper for input capacitance of $\rm C_f =0.1~pF, ~0.2~pF,~0.4~pF,~0.8~pF~and~1.5~pF$ (left) and residuals for operation in the physics mode (right). The dashed (red) lines show a $\pm 0.5\%$ deviation from linearity.
Linearity measurements of preamplifier and shaper for input capacitance of $\rm C_f =0.1~pF, ~0.2~pF,~0.4~pF,~0.8~pF~and~1.5~pF$ (left) and residuals for operation in the physics mode (right). The dashed (red) lines show a $\pm 0.5\%$ deviation from linearity.
Measurements of the DAC linearity of 18 channels (left) and residuals for channel zero (right).
Measurements of the DAC linearity of 18 channels (left) and residuals for channel zero (right).
The VFE AHCAL base board with six mezzanine boards. The connection to the SiPMs is via coaxial cables.
The emission spectrum of the UV LED.
Layout of the LED driver.
Photograph of the calibration and monitoring board.
Left: Distribution of single pixel peaks measured in the gain calibration. The superimposed curve is a fit with multiple Gaussian functions. Right: The MIP distribution of muons measured in a cell in the physics mode. The superimposed curve is a fit to a Landau distribution convolved with a Gaussian function. The noise spectrum is shown as a reference.
Left: Distribution of single pixel peaks measured in the gain calibration. The superimposed curve is a fit with multiple Gaussian functions. Right: The MIP distribution of muons measured in a cell in the physics mode. The superimposed curve is a fit to a Landau distribution convolved with a Gaussian function. The noise spectrum is shown as a reference.
Left: Comparison of SiPM readout and PM readout for a 5~GeV $e^+$ beam showering in a 5~$X_0$ thick lead absorber for uncorrected data (crosses), corrected data (solid points) and a GEANT3 simulation (squares); Right: Residuals of the SiPM data and simulation for uncorrected (crosses) and corrected data (solid points).
CALICE calorimeter system setup at CERN in 2006 (left) and 2007 (right).
CALICE calorimeter system setup at CERN in 2006 (left) and 2007 (right).
Event collection rate during test beam in 2006 (left) and 2007 (right).
Event collection rate during test beam in 2006 (left) and 2007 (right).
Three-dimensional event display of a muon from the test beam penetrating the ECAL, AHCAL and TCMT. Hits in the TCMT are indicated by the colored bars.
Average MIP detection efficiency in each calorimeter layer (left). Average signal-to-noise ratio in each calorimeter layer for a MIP signal (right). The bands indicates the spread among the tiles in one layer.
Average MIP detection efficiency in each calorimeter layer (left). Average signal-to-noise ratio in each calorimeter layer for a MIP signal (right). The bands indicates the spread among the tiles in one layer.
Recorded light yields in the test beam.
Distributions of total energy (left) and number of hits (right) for noise (red solid histogram), MIP spectra (unshaded blue histogram), and their combination (dark-shaded black) in the AHCAL. The area of the distributions are normalized to one.
Distributions of total energy (left) and number of hits (right) for noise (red solid histogram), MIP spectra (unshaded blue histogram), and their combination (dark-shaded black) in the AHCAL. The area of the distributions are normalized to one.
Noise hits as a function of reverse bias voltage with a threshold of half a MIP.
SiPM noise during two years of operation in test beams. The pedestals are generally between 20 and 60 ADC bins and the number with a given pedestal RMS is stable with time
Event displays of a $20$~GeV/c pion from the online monitor, showing a three dimensional view (left) and a side view (right). The beam is coming from the right-hand side. The shower starts in the middle of AHCAL. Hits in the TCMT are indicated by the colored bars.
Event displays of a $20$~GeV/c pion from the online monitor, showing a three dimensional view (left) and a side view (right). The beam is coming from the right-hand side. The shower starts in the middle of AHCAL. Hits in the TCMT are indicated by the colored bars.