8 Neutrino Detectors
361
• The cathode plane was rebuilt to correct for up to 5 mm non-planarity.
• The optical system was upgraded to 360 8 Hamamatsu 5912-mod (10 stage)
cryogenic photomultipliers with TPB coating their face and read out by the
CAEN V1730B 500 MHz 14 bit ADC system. The speed of this readout should
allow the correlation of beam events with the Booster RF substructure, namely
1.15 ns pulses separated by 19 ns. If achieved, this correlation will reduce further
the contamination of cosmic rays.
• The TPC electronics was modified as follows. The analogue signal shaping
time was reduced to 1.5μs to match the electron transit time between wire
planes and reduce undershoot in induction. Serial ADCs as well as a serial bus
architecture with optical links were adopted. The feedthrough flange was used as
the electronics backplane.
The third detector, SBND, described and referred to as LAr1-ND in [83], is a
detector intended to measure the intrinsic beam composition, in particular of ν e ,
before oscillations can occur. However its closeness to the neutrino target ensures a
large number of neutrino interactions and hence a rich cross-section measurement
programme. Its dimensions are 5 m along the beam, 4 m in height and 4 m laterally.
The electrons drift along this latter dimension which consists of two 2 m drift spaces
placed side by side. The Cathode Plane Assembly, CPA, is located in the middle
and one Anode Plane Assembly, APA, is placed on either side and consists of the
same number of wire planes and orientation as MicroBooNE. Each APA is made
up of two 2.5 m wire frames along the beam but the U and V wires are connected
to ensure continuous coverage. Unlike MicroBooNE, the ADCs will be in the cold
together with the front end pre-amplifiers and shapers. The digitized signals will
be multiplexed out of the cryostat via an FPGA. This will reduce the electronic
noise and reduce the size of feed throughs. Upon exitting from the cryostat the
signals will be converted to optical signals and sent, over optical fibres, to the warm
DAQ electronics which will be identical to the one used by MicroBooNE. A 100 kV
high voltage will provide a 500 V/cm drift field, the uniformity of which will be
ensured by a field cage constructed with roll-formed tubes. A cosmic ray tagger of
similar construction to the MicroBooNE one and a membrane cryostat will encase
the detector. The light detection sytem will use the same pmt type and readout
system as ICARUS. SBND will pioneer several detector concepts such as APAs
and CPAs intended to be applied to the DUNE detector.
The liquid argon technique has been chosen for DUNE [88], the Deep Underground Neutrino Experiment ν μ → ν e oscillation search intended to determine
whether CP is violated in the neutrino sector and to measure the mass hierarchy. It
will also address non-neutrino beam physics such as potential supernovae, proton
decay and nnbar oscillations. The liquid argon technique was chosen instead of that
of water Cerenkov for its good electron/photon discrimination resulting in a higher
electron efficiency and therefore the possibility to use a smaller detector to achieve
the same sensitivity. DUNE will be located 1475 m underground at SURF [89],
the Sanford Underground Research Facility, in Lead, South Dakota and will be
observing neutrinos produced at Fermilab 1300 km away. It will consist of four
361
• The cathode plane was rebuilt to correct for up to 5 mm non-planarity.
• The optical system was upgraded to 360 8 Hamamatsu 5912-mod (10 stage)
cryogenic photomultipliers with TPB coating their face and read out by the
CAEN V1730B 500 MHz 14 bit ADC system. The speed of this readout should
allow the correlation of beam events with the Booster RF substructure, namely
1.15 ns pulses separated by 19 ns. If achieved, this correlation will reduce further
the contamination of cosmic rays.
• The TPC electronics was modified as follows. The analogue signal shaping
time was reduced to 1.5μs to match the electron transit time between wire
planes and reduce undershoot in induction. Serial ADCs as well as a serial bus
architecture with optical links were adopted. The feedthrough flange was used as
the electronics backplane.
The third detector, SBND, described and referred to as LAr1-ND in [83], is a
detector intended to measure the intrinsic beam composition, in particular of ν e ,
before oscillations can occur. However its closeness to the neutrino target ensures a
large number of neutrino interactions and hence a rich cross-section measurement
programme. Its dimensions are 5 m along the beam, 4 m in height and 4 m laterally.
The electrons drift along this latter dimension which consists of two 2 m drift spaces
placed side by side. The Cathode Plane Assembly, CPA, is located in the middle
and one Anode Plane Assembly, APA, is placed on either side and consists of the
same number of wire planes and orientation as MicroBooNE. Each APA is made
up of two 2.5 m wire frames along the beam but the U and V wires are connected
to ensure continuous coverage. Unlike MicroBooNE, the ADCs will be in the cold
together with the front end pre-amplifiers and shapers. The digitized signals will
be multiplexed out of the cryostat via an FPGA. This will reduce the electronic
noise and reduce the size of feed throughs. Upon exitting from the cryostat the
signals will be converted to optical signals and sent, over optical fibres, to the warm
DAQ electronics which will be identical to the one used by MicroBooNE. A 100 kV
high voltage will provide a 500 V/cm drift field, the uniformity of which will be
ensured by a field cage constructed with roll-formed tubes. A cosmic ray tagger of
similar construction to the MicroBooNE one and a membrane cryostat will encase
the detector. The light detection sytem will use the same pmt type and readout
system as ICARUS. SBND will pioneer several detector concepts such as APAs
and CPAs intended to be applied to the DUNE detector.
The liquid argon technique has been chosen for DUNE [88], the Deep Underground Neutrino Experiment ν μ → ν e oscillation search intended to determine
whether CP is violated in the neutrino sector and to measure the mass hierarchy. It
will also address non-neutrino beam physics such as potential supernovae, proton
decay and nnbar oscillations. The liquid argon technique was chosen instead of that
of water Cerenkov for its good electron/photon discrimination resulting in a higher
electron efficiency and therefore the possibility to use a smaller detector to achieve
the same sensitivity. DUNE will be located 1475 m underground at SURF [89],
the Sanford Underground Research Facility, in Lead, South Dakota and will be
observing neutrinos produced at Fermilab 1300 km away. It will consist of four