Field of Interest:nucl-ex
Experiments:JUNO
Deadline: 2018-02-23
Region: Europe
Job description:
The neutrino is a neutral particle interacting only through the weak interaction. It shows up today as the
messenger of new physics beyond the Standard Model. Indeed, in this theory, this elementary particle is
considered massless which runs counter to the experimental observation of neutrino oscillations, which is only
possible if the neutrino masses are different. The observation of this phenomena constitutes a fundamental
advance in particle physics, and awarded the 2015 Nobel prize to two experiments, Super-Kamiokande and
SNO, which significantly contributed to this discovery.
Since this discovery in 1998, several experiments have studied this phenomena however there are still some
parameters that haven’t been measured yet. One of these unknown parameters is linked to the neutrino
mass ordering, that is which of the neutrinos 1 (composed of mostly e) or 3 (composed of a mix of and
) is the lightest. The determination of this ordering could be essential to understand by which mechanism
the neutrinos gets its mass and also to check expansion models of the Universe.
The JUNO (Jiangmen Underground Neutrino Observatory [1]) experiment’s main goal is to answer this
question. It is expected to reach a sensitivity of more than 3 to measure the neutrino mass ordering after
6 years of data taking. JUNO will also make it possible to precisely measure several parameters of the neutrino
mixing matrix which will allow us to start testing its unitarity. JUNO will also perform measurements on
geo-neutrinos, solar neutrinos, atmospheric neutrinos, and supernovae neutrinos. The construction of the
experimental hall in southern China has started, and the detector construction is expected to start in 2018
with data taking starting at the end of 2020.
JUNO is an international experimental collaboration, regrouping 71 institutions all around the world. The
experiment will use neutrinos from many nuclear power plants with a total power of 36 GW. The detector
will be at 53 km from the cores of the reactors, and the target will be made of a liquid scintillator making
it possible for us to detect electron anti-neutrinos emitted by the reactor cores. The scintillation light will
be collected by about 17000 20 inch photomultiplier tubes (PMT) and 25000 3 inch photomultiplier tubes.
The central detector, composed of the liquid scintillator inside an acrylic sphere, will be surrounded by a
water pool equipped of PMTs – making a Cherenkov detector – that will identify atmospheric muons inducing
cosmogenic background. An additional detector, the Top Tracker, will be installed above the central detector
and the water pool to further identify atmospheric muons.
The Strasbourg group will use the Target Tracker of the OPERA experiment as the Top Tracker (TT)
of JUNO. This fundamental part of the OPERA detector was fully IPHC’s responsibility (construction,
installation and data analysis). This contribution makes it possible for the IPHC group to have great
visibility and have an essential role within the JUNO collaboration. OPERA’s Target Tracker is currently
in China, and will be installed in top of the JUNO detector. Changes to the electronic cards and acquisition
system of the TT will have to be made as the counting rate expected is significantly larger than for OPERA.
This work is taking place by the Strasbourg group in collaboration with other laboratories. The Strasbourg
group will take part in the TT data analysis, particularly through the simulation, track reconstruction and
estimation of background noise for JUNO.
The goal of this Ph.D. thesis is to optimize the Top Tracker before its foreseen installation in 2019, optimize
the simulation and track reconstruction software, and then determine the TT performance to reduce the
cosmogenic background noise and estimate its impact to JUNO’s systematic uncertainties. In parallel to the
work on the analysis, the student will join the testing of the new electronics for the TT.
[1] JUNO website: http://juno.ihep.cas.cn
More Information:http://www.iphc.cnrs.fr/-Theses-Stages-.html
Experiments:JUNO
Deadline: 2018-02-23
Region: Europe
Job description:
The neutrino is a neutral particle interacting only through the weak interaction. It shows up today as the
messenger of new physics beyond the Standard Model. Indeed, in this theory, this elementary particle is
considered massless which runs counter to the experimental observation of neutrino oscillations, which is only
possible if the neutrino masses are different. The observation of this phenomena constitutes a fundamental
advance in particle physics, and awarded the 2015 Nobel prize to two experiments, Super-Kamiokande and
SNO, which significantly contributed to this discovery.
Since this discovery in 1998, several experiments have studied this phenomena however there are still some
parameters that haven’t been measured yet. One of these unknown parameters is linked to the neutrino
mass ordering, that is which of the neutrinos 1 (composed of mostly e) or 3 (composed of a mix of and
) is the lightest. The determination of this ordering could be essential to understand by which mechanism
the neutrinos gets its mass and also to check expansion models of the Universe.
The JUNO (Jiangmen Underground Neutrino Observatory [1]) experiment’s main goal is to answer this
question. It is expected to reach a sensitivity of more than 3 to measure the neutrino mass ordering after
6 years of data taking. JUNO will also make it possible to precisely measure several parameters of the neutrino
mixing matrix which will allow us to start testing its unitarity. JUNO will also perform measurements on
geo-neutrinos, solar neutrinos, atmospheric neutrinos, and supernovae neutrinos. The construction of the
experimental hall in southern China has started, and the detector construction is expected to start in 2018
with data taking starting at the end of 2020.
JUNO is an international experimental collaboration, regrouping 71 institutions all around the world. The
experiment will use neutrinos from many nuclear power plants with a total power of 36 GW. The detector
will be at 53 km from the cores of the reactors, and the target will be made of a liquid scintillator making
it possible for us to detect electron anti-neutrinos emitted by the reactor cores. The scintillation light will
be collected by about 17000 20 inch photomultiplier tubes (PMT) and 25000 3 inch photomultiplier tubes.
The central detector, composed of the liquid scintillator inside an acrylic sphere, will be surrounded by a
water pool equipped of PMTs – making a Cherenkov detector – that will identify atmospheric muons inducing
cosmogenic background. An additional detector, the Top Tracker, will be installed above the central detector
and the water pool to further identify atmospheric muons.
The Strasbourg group will use the Target Tracker of the OPERA experiment as the Top Tracker (TT)
of JUNO. This fundamental part of the OPERA detector was fully IPHC’s responsibility (construction,
installation and data analysis). This contribution makes it possible for the IPHC group to have great
visibility and have an essential role within the JUNO collaboration. OPERA’s Target Tracker is currently
in China, and will be installed in top of the JUNO detector. Changes to the electronic cards and acquisition
system of the TT will have to be made as the counting rate expected is significantly larger than for OPERA.
This work is taking place by the Strasbourg group in collaboration with other laboratories. The Strasbourg
group will take part in the TT data analysis, particularly through the simulation, track reconstruction and
estimation of background noise for JUNO.
The goal of this Ph.D. thesis is to optimize the Top Tracker before its foreseen installation in 2019, optimize
the simulation and track reconstruction software, and then determine the TT performance to reduce the
cosmogenic background noise and estimate its impact to JUNO’s systematic uncertainties. In parallel to the
work on the analysis, the student will join the testing of the new electronics for the TT.
[1] JUNO website: http://juno.ihep.cas.cn
More Information:http://www.iphc.cnrs.fr/-Theses-Stages-.html