Summer Student Program

at Joint Institute for Nuclear Research

Projects list

This list is intended to inform potential participants of the Summer Student Program at JINR about the projects offered by particular supervisors. This list does not exhaust all the available projects of the Program and only reflects the projects wished to be announced by potential supervisors. If desired, the applicants may refer to the projects on the list in their motivation letters.


Description:

The project aims are to provide students with knowledge and practice in the computer simulation modelling, methods of statistical analysis of data to evaluate the accuracy and reliability of the results, the fundamentals of wavelet analysis, applications of artificial neural networks and cluster analysis.
Possible project topics in 2016 Summer Student Program at JINR:
  • wavelet-analysis application for finding small peaks in experimental spectra;
  • wavelet-analysis application for separation and parameterization of close signals;
  • application of informational methods of social network analysis for revealing social group structures;
  • development of data compression program based on neural network application;
  • development of algorithms and programs for clustering responses of tracking detectors with a pad structure.
Requirements to students:
  • ability to program in C++ under Linux operational system;
  • basic skill how to use the ROOT library;
  • basic knowledge about artificial neural nets and wavelet transformations;
  • knowing English at least for reading.
Description:

Introduction

The phase dynamics in superconducting nanostructures has attracted a great attention because of rich and interesting physics from one side and perspective of applications from the other one.  The phase dynamics investigations of intrinsic Josephson junctions in high temperature superconductors are interesting in the context of coherent radiation emission.

In during of the project period the student will study the physics of superconducting nanostructures and get the experience in the computer simulation of their physical characteristics.

Description of the project

The students will concentrate on the computer simulation of the phase dynamics in superconducting nanostructures. The example of the current-voltage characteristics (CVC) simulated for the stack with 10  intrinsic Josephson junctions (IJJ) in high temperature superconductor is presented in left figure. The breakpoint shown in the inset is a parametric resonance point where the longitudinal plasma wave is created in this stack. In right figure we demonstrate the profile of the electric charge on the first superconducting layer. The details are in the recommended papers.

       
 

 
 

 


Figure:  (Left)- The simulated CVC of a stack of 10 IJJ.  The inset shows the enlarged breakpoint region (BPR) for the last branch in CVC. (Right)- Charge oscillation in the first layer in the beginning of B-S part of the BPR. The inset shows the oscillations in the layers 1 and 2.

The problems for students:

1. Investigation of the resonance phenomena in superconducting nanostructures  under microwave radiation.

2. Study of spintronics phenomena by numerical calculations

3. Investigation of the charge imbalance effect in superconducting nanostructures.

4. Majorana physics in Josephson junctions

Results of the project will be presented in the form of the report, which might be considered as a version for scientific paper.

Acceptance criteria

Some experience in computer simulation

Number of the participants

The number of the participants is limited by three students.

Recommended literature

1.    Werner Buckel, Reinhold Kleiner. Superconductivity. Fundamentals and Applications, Wiley-VCH,  2004.

2.    Yu. M. Shukrinov, I. R. Rahmonov, K. V. Kulikov and P. Seidel. E_ects of LC shunting on the Shapiro steps features of Josephson junction. - Europhysics Letters, 110 (2015)

3.    M. Maiti, K. M. Kulikov, K. Sengupta, Yu. M. Shukrinov. Josephson junction detectors for Majorana modes and Dirac fermions. Phys. Rev. B 92, 224501 (2015).

Supervisor of the project

Dr., Prof. Yury M. Shukrinov, leading researcher of BLTP, 100 scientific publications.

E-mail address: shukrinv@theor.jinr.ru   Phone: +7-49621-63844

Description:

Development of algorithms for solving the direct and inverse problems for the Tolman-Oppenheimer-Volkoff equation, which describes the structure of compact star

Required skills
Programing with C/C++, basic skills in numerical methods for DE, basics skills in thermodynamics and general relativity are desirable

Learning experience
The candidate will get experience in modelling of the realistic structures of compact stars, such as pulsars and white dwarfs, and in development of the effective algorithms of solving non-linear Des, additionally, he will learn the basic of the computational astrophysics.

Project duration
1 to 2 months

Project area
Mathematical Modeling and Computational Physics

Supervisors
A. Ayriyan (LIT), ayriyan@jinr.ru
H. Grigorian (LIT), hovik.grigorian@gmail.com

Recommended References
I. Bombaci, The Maximum Mass of a Neutron Star, Astronomy and Astrophysics 305 (1996), pp. 871–877
Description:

Development of algorithms of solving the optimization problem for the heat equation in order to find the optimal geometry of the thin plate to provide the given heat distribution on its surface

Required skills
Programing with C/C++, basic skills in numerical methods for PDE

Learning experience
The candidate will get experience in formulation and solving the optimization problems for PDE, and in development of the effective algorithms for its numerical realization

Project duration
1 to 2 months

Project area
Mathematical Modeling and Computational Physics

Supervisor
A. Ayriyan (LIT), ayriyan@jinr.ru

Recommended References
A. A. Samarskii, P. N. Vabishchevich. Computational Heat Transfer. NY: Wiley, Volume 1, 1996. - 418 p.
Description:

Description
Development of effective algorithms for finding the stationary solutions of the Schrodinger equation as an end state of time evolution process

Required skills
Programing with C/C++, basic skills in numerical methods for DE, basic knowleges in quantom mekhanics and operator algebra are desirable

Learning experience
The candidate will get experience in modelling of the particle bound states, and in development of the effective algorithms for solving non-linear eigenvalue problems

Project duration
1 to 2 months

Project area
Mathematical Modeling and Computational Physics

Supervisor
H. Grigorian (LIT), hovik.grigorian@gmail.com

Recommended References
Luca Nanni The Hydrogen Atom: a Review on the Birth of Modern Quantum Mechanics (англ.). — arΧiv: 1501.05894.
William H. Press, Saul A. Teukolsky, William T. Vetterling, Brian P. Flannery. Numerical Recipes 3rd Edition: The Art of Scientific Computing 3rd Edition. NY: Cambridge University Press. —   1256 p.
Description:

An example of a CMS event with large total transverse energy (ST=2.6 TeV) and high jet multiplicity (9 jets, denoted by light purple cones and lines)
The search for microscopic black holes at the LHC is motivated by the hierarchy problem — the huge observed difference between the strengths of the electroweak and gravitational forces. The 
ADD model (Arkani-Hamed, Dimopoulos, and Dvali) offers an explanation by introducing extra dimensions of space beyond the usual three: Only gravity “feels” these extra dimensions in space, while all other interactions (electromagnetism, strong and weak forces) are constrained to a 3D slice (or “brane”) of a multi-dimensional Universe. This effectively dilutes the gravitational force and makes it appear weaker to an observer who “lives” on a 3D brane. One consequence of such large (compared to Planck scale) extra dimensions is that when two particles approach each other very closely in a high-energy collision they could feel the full strength of gravity in the extra dimensions, which may be sufficient for them to form a microscopic back hole.

Details are here: Phys. Lett. B 697 (2011) 434
Description:

In the framework of this field there are three different projects:  Project_1Project_2Project_3
Description:

Description of thermodynamical equlibrium between cold hadronic and quark matter phases under conditions of compact stars.
 
Required skills
Programing with C/C++, basics skills in thermodynamics, particularly the Gibbs condition for phase equilibrium
 
Learning experience
The candidate will get experience in modelling of the phase transition with uncertain parameter of the interfacial tension and application in the compact star physics.
 
Project duration
1 to 2 months
 
Project area
Mathematical Modeling and Computational Physics
 
Supervisors
H. Grigorian (LIT), hovik.grigorian@gmail.com
A. Ayriyan (LIT), ayriyan@jinr.ru
 
References
Norman K. Glendenning. First-order phase transitions with more than one conserved charge: Consequences for neutron stars. Physical Review D 46 (1992), 1274-1287
Description:

Development of parallel pipe-line algorithm for solution of the initial-boundary-value problem for parabolic and elliptic PDE using difference methods.
 
Required skills
Programing with C/C++, basic skills in numerical methods for PDE
 
Learning experience
The candidate will get experience in development of the unusual parallel algorithm for solving parabolic PDE
 
Project duration
1 to 2 months
 
Project area
Mathematical Modeling and Computational Physics
 
Supervisor
A. Ayriyan (LIT), ayriyan@jinr.ru
 
References
A. A. Samarskii, P. N. Vabishchevich. Computational Heat Transfer. NY: Wiley, Volume 1, 1996. - 418 p.
P. Purcz. Parallel algorithm for spatially one-and two-dimensional initial-boundary-value problem for a parabolic equation // Kybernetika (2001), vol. 37, iss. 2, pp. 171-181
Description:

Tier-1 computing center for processing of the CMS data is situated in the laboratory of information technologies in JINR. Tier-1 unites more than 2000 of computing cores and more than 5 PB of storage. In order to increase reliability and reduce down-time of the center the new monitoring system based on Nagios was introduced. It collects data from the lowest level: temperature, CPU and RAM load, etc.
But it is not enough. Critical software and services fails on Tier-1 sometimes. Service monitoring is essential for keeping track on these fails. To increase the up-time of the center new monitoring system development was initiated. This new monitoring system consists of two subsystems: data collection (Python, Beautiful Soup, PostgreSQL) and data visualisation(Django, javascript, jquery, mvc, different visualisation libraries for js).
Now we have a task to improve the development process (DevOps) by introducing new technologies and techniques. We look for a candidate with a good knowledge of:
   1. Web-development
   2. Git
   3. Build systems(grunt or grub)
   4. JavaScript
   5. Linux.
The following skills would be an advantage: Python, Django, continuous integration, unittests.
Description:

Development of data visualization components for web UI.

Required Skills:
- Ability to apply fundamental engineering principles (Separation of Concerns, Loose Coupling, Less is More, Abstraction, Modularity/Reusability, SOLID, DRY, YAGNI)
- Object-oriented development (familiarity with classes, properties, methods, constructors, design patterns)
- Web development (familiarity with HTML, CSS, Javascript, APIs)

Learning Experience:
The candidate will get experience of a technology development with a team of professionals.

Project duration:
6-8 weeks

Project Area:
Computer Vision

Supervisor:
S. Hnatic (LIT), drhnatic@drhnatic.com

Description:

General info: 

NOvA is a new generation off-axis long-baseline neutrino experiment designed to measure muon (anti)neutrino oscillation parameters. NOvA experimental setup consists of a large volume far detector situated at a distance of 810km and a smaller near detector at 1km, which is used to perform relative measurements.  Operating in total for 6 years in the intense neutrino and antineutrino NuMI beams at Fermilab the NOvA experiment will achieve unprecedented sensitivity to the neutrino mass hierarchy and parameters of lepton CP parity violation – two fundamental questions essential for our understanding of the neutrino role in particle physics, cosmology and possible new physics.

NOvA experiment started operation in 2014 and a number of important measurements have been performed on the basis of statistics collected so far: an electron neutrino appearance signal measurement has allowed for the restriction of the  hierarchy-deltaCP parameter space, a muon neutrino disappearance signal was measured confirming oscillation parameters Δm2 and sinθ with high precision, moreover, from the NOvA data the θ23 maximal mixing was excluded for the first time with ~3σ confidence level.    

Continuing the data collection, and importantly, altering neutrino and anti-neutrino beams, NOvA can unambiguously resolve the neutrino mass hierarchy at >95% C.L. for over a third of possible values of δ. For other values of this CP violation parameter, NOvA will provide δ-dependent hierarchy determination plus improved measurements of θ13θ23, |∆m223|, and δ itself, which is also very important for global analysis of the neutrino oscillation data.    

Dubna team: 

The JINR group in NOvA has contributed significantly to the NOvA results. The Remote Operation Center (ROC-Dubna) was developed at JINR, giving the possibility to fully participate in the data taking and quality monitoring. The JINR computer infrastructure on the basis of GRID and Cloud technologies was developed. It is efficiently used for the home-based running of jobs and is also  a part of the NOvA distributed computing resources system for the use at peak loads (e.g., before conferences). The NOvA electronics test bench was set up at JINR and provided important measurements of electronics parameters used for simulation and calibration. 

Members of the JINR group are deeply involved in the ongoing analyses and in the preparation of new ones. This comprises the νμ, νe, Supernova, Slow monopole, Cosmic Ray and Near Detector physics teams. They are also involved in the development of simulation and analyses software, and are serving as a Detector Simulation convener, Offline and DAQ Software Release Managers, DAQ, DDT and ROC experts, etc.

Research tasks for the students:

1   Working with NOvA-Offline package to study neutrino oscillation phenomena and neutrino interactions with matter.
2   Development of supenova triggering system, optimization of background reduction and statistical analysis.
3   Search for monopoles and cosmic ray physics studies in the large volume Far Detector.
4   Study of liquid scintillator properties and front-end electronics.
5   Deployment and development of the computing systems for the NOvA.

Usefull links

1   https://www-nova.fnal.gov 
2   http://astronu.jinr.ru/wiki/index.php/NOvA_Experiment
3   https://cdcvs.fnal.gov/redmine/projects/novaart/wiki 

The tasks require working knowledge of modern computer programming and scripting languages (C++, Python, ROOT). Linux experience is useful to quick start. For 2nd task, statistics knowledge, machine learning skills would be much appreciated. For 4th task, basic knowledge of electronics, low level programming, MatLab is very helpful. 5th task requires Unix-like systems administration basics and basic ruby/python scripting, web-development skills (html, js, css, ajax) would be an advantage.

Description:

Прецизионная лазерная метрология для ускорителей и детекторных комплексов

АННОТАЦИЯ

Проект лазерного измерительного комплекса, включает Лазерную Реперную Линию,  Прецизионный Лазерный Инклинометр и Абсолютный Измеритель Длины. Он предназначен для метрологического сопровождения  современных ускорителей-коллайдеров и крупномасштабных детекторных комплексов.

Лазерная Реперная Линия с неопределённостью в пространственной координате луча менее десяти микрон обеспечивает прецизионную юстировку основных структурных компонентов коллайдеров и спекторометров. При помощи ЛРЛ также возможен on-line контроль пространственной конфигурации отдельных элементов детекторного комплекса при проведении эксперимента.

Прецизионный Лазерный Инклинометр измеряет угловые микросейсмические движения поверхности Земли  с точностью 10-9 рад, что открывает возможность стабилизации пространственного положения ЛРЛ, параметров пучков, увеличения  светимость коллайдера, повыение точности измерений углов и импульсов в спектрометрах.

Абсолютный Измеритель Длины с точностью измерения 1 мкм на длине 10 м позволит связать координатные системы секторов коллайдера, разделённых детекторным комплексом.

Предполагается, что представленные метрологические инструменты будут работать как единый Лазерный измерительный комплекс во время наборных сеансов и плановых остановках коллайдера.

The Precision Laser Metrology for Accelerators and Detector Complexes

ABSTRACT

The Project proposes the creation of Laser Measurement Complex including the Laser Fiducial Line, Precision Laser Inclinometer and Absolute Distance Meter. The Complex is intended for solving of the tasks of the metrology accompanying of modern large scale accelerators (colliders) and detector systems.

The LASER FIDUCIAL LINE serves to precision adjustment of the accelerator structure units on micron level. The on-line control of the space configuration of internal components of detector complex is also possible allowing the significant decrease of the components space location uncertainties.

The PRECISION LASER INCLINOMETER will measure with 10-9 rad accuracy the microseismic ground motion making possible to improve the space stabilization of the colliding beams parameters in the collision area leading to luminosity increase and improving the momentum and angular measurement precision.

The ABSOLUTE DISTANCE METER with 1 micron measurement precision on the distance by 10 meters will solve on new accuracy level the important task to connect the collider's coordinate systems separated by detector complex.

It is assumed that the above new generation metrology tools will act as unite Laser Measurement Complex during the data taking Runs and scheduled technical stops.

http://indico.jinr.ru/getFile.py/access?contribId=24&resId=0&materialId=1&confId=1314

Description:

The MPD is a multi-purpose detector designed for registering particles emitted during collisions of heavy ions. The detector is part of NICA (Nuclotron-based Ion Collider facility), an experimental complex housed in the Joint Institute for Nuclear Research (JINR) in Dubna.

 

Among the various components of the MPD is the time of flight detector (TOF). On the basis of temperature measurements taken within the TOF, a temperature regulation and stabilization system should be designed.

 

The main task is to prepare simulation of heat transfer inside the TOF. After that student will build the slow control and the data acquisition systems for measuring the temperature inside the detector.

 

We look for a candidate with a good knowledge of:

 

- LabView,

-C++,

-Electronics,

-basics skills in thermodynamics.


Project duration

1 to 2 months

Description:

     Experimental and theoretical studies of direct photon production in hadronic collisions essentially expand our insights about multiparticle production mechanisms. These photons are useful probes to investigate nuclear matter at all stages of the interaction. Soft photons (SP) play a particular role in these studies. Until now we have no explanation for the experimentally observed excess SP yield. These photons have low energy transverse moment pT < 0.1 GeV/c, |x|      In theoretical works, developed in the field of pion condensate search there is an indication on the possible connection of this condensate with an anomalous soft photon yield. Our Collaboration has succeeded finding out behavior of scaled variance of neutral pion number in the high total multiplicity region that testifies to formation of pion condensate. Research of soft photon yield in proton, proton-nuclei and nuclear interactions and establishment of connection of anomalous soft photons with Bose-Einstein condensate will be the following experimental studies at Nuclotron JINR. Also we prepare extensive physical program based at photon detection by electromagnetic calorimeter.                                                                                        
     The manufactured ourselves electromagnetic calorimeter allows registering photons from several keV. Research of a soft photon yield has been begun in nuclear interactions at 3.5 GeV/nucl at Nuclotron . It is planned to investigate the dependence of their yield on multiplicity of charged, neutrals and total multiplicity in the high multiplicity region. Such research is unique and allows coming closer to understanding of a physical picture of soft photon formation and the nature of hadronization.                                                                                  
    During summer practice students will take account at making of electronic devices for registration of soft photons by electromagnetic calorimeter based on "shashlyk" moduls. It is necessary to lower energy threshould of gamma-quantum registration. Also very important work before experiment is Monte Carlo simulation of setup performance. We hope that students will get different experience at the experimental and theoretical activity.





Description:

In this project, it will be proposed to carry out research on a topic that is in the active development stage in the CMS experiment. The work includes:
 
- study of the specialized software of the CMS experiment and built-in modules for simulation of hadron-hadron collisions (generators Pythia, Herwig) and jet reconstruction software (FastJets), package for the statistical analysis (ROOT);
 
- study of the fundamentals of the physics of jets (from the primary parton to the perturbative and nonperturbative stages of jet formation),
- Performing work on the modeling of physical processes for the measurement of charge multiplicity in quark and gluon jets at the CMS.

Requirements for a candidate:
  
- Basic knowledge of C ++,
  
- Fundamentals of elementary particle physics.

Description:

Введение

В рамках научной программы по изучению горячей и плотной барионной материи в ОИЯИ реализуется проект по созданию нового ускорительного комплекса на встречных пучках NICA (Nuclotron-based Ion Collider fAcility) на базе существующего ускорителя Нуклотрон.

Коллайдер NICA предусматривает две точки пересечения пучков, в одной из которых будет располагаться экспериментальная установка - Многоцелевой детектор (Multi-Purpose Detector, MPD).

Основным детектором для регистрации треков заряженных частиц и их идентификации в MPD является время-проекционная камера (Time-Projection Chamber - TPC).

               Краткое описание детектора TPC/MPD

ТРС представляет собой двойную дрейфовую камеру, симметричную относительно центрального высоковольтного электрода. Соответственно рабочий газовый объем камеры также разделен этим центральным электродом.

Для считывания информации в ТРС используются по 12 пропорциональных камер (ReadOut Chamber, ROC) с катодной пэдовой плоскостью считывания, которые симметрично расположены на торцах ТРС. Пэдовая плоскость выполнена по технологии многослойной печатной платы.

Чтобы обеспечить требуемую точность измерения координат треков заряженных частиц, неоднородность электрического поля в дрейфовом объёме детектора не должна превышать 10-4.

Однородное электрическое поле внутри детектора создаётся системой формирующих поле электродов (field cage), которые представляют из себя полосы алюминизированного майлара. Ширина полос 13 мм, они располагаются с шагом 15 мм на специальных поддерживающих трубках вдоль стенок корпуса рабочего объёма ТРС.

Более подробную информацию о мега-проекте NICA и эксперименте MPD можно прочитать, например, на веб-сайтах: http://nica.jinr.ru/, http://mpd.jinr.ru/.

Более подробно о конструкции детектора TPC/MPD и информацию по некоторым предварительным расчётам электрического поля внутри TPC [1, 4, 5], можно почитать в источниках:

1.  Time Projection Chamber for Multi-Purpose Detector at NICA. Technical Design Report (rev.04), A. Averyanov, A. Bazhazhin, et al., Dubna, VBLHEP JINR, 2016, http://nica.jinr.ru/files/TDR_MPD/TpcTdr_26-05-2016.pdf;

2. International Journal of Humanities and Natural Sciences (Международный журнал гуманитарных и естественных наук), Nov., 2016, V. 2, № 1, p. 208-213, STATUS OF THE TIME PROJECTION CHAMBER FOR THE MPD/NICA PROJECT, A. Averyanov, A. Bazhazhin, et al.,
http://intjournal.ru/wp-content/uploads/2016/11/Mezhdunorodnyj-ZHurnal-1-tom-2-1.pdf;

3. Acta Physica Polonica B (Proceedings Supplement), 2016, V. 9, № 2, p. 155-164, TIME PROJECTION CHAMBER FOR MULTI-PURPOSE DETECTOR AT NICA, A. Averyanov, A. Bajajin, et al.,
http://www.actaphys.uj.edu.pl/fulltext?series=Sup&vol=9&page=155;

4. Труды XVIII Международной научной конференции молодых ученых и специалистов к 105-летию Н.Н. Боголюбова (ОМУС-2014), 24-28 фев., 2014, ОИЯИ, Дубна, ISBN 978-5-9530-0384-1, с. 117-120, Время-проекционная камера (TPC) детектора MPD для коллайдера NICA, Ю.В. Заневский, С.В. Разин, А.Г. Бажажин, и др.,
http://omus.jinr.ru/conference2014/conference_proceedings_2014.pdf;

5. Труды XVIII Международной научной конференции молодых ученых и специалистов к 105-летию Н.Н. Боголюбова (ОМУС-2014), 24-28 фев., 2014, ОИЯИ, Дубна, Россия, ISBN 978-5-9530-0384-1, с. 252-255, Результаты моделирования электрического поля в TPC используя программный пакет ANSYS Maxwell, Ю.В. Заневский, С.В. Разин, А.Г. Бажажин,
http://omus.jinr.ru/conference2014/conference_proceedings_2014.pdf;

6. Journal of Instrumentation, 2014, V. 9, p. С07-016, The Multi-Purpose Detector for JINR heavy-ion collider, Stepan Razin on behalf of the MPD group,
http://iopscience.iop.org/article/10.1088/1748-0221/9/07/C07016;

7. Journal of Instrumentation, 2014, V. 9, p. C09-036, Time-Projection Chamber for the MPD NICA project, A. Averyanov, A. Bajajin, et al.,
http://iopscience.iop.org/1748-0221/9/09/C09036/refs;

8. Ядерная физика и инжиниринг, 2013, Том 4, № 9-10, с. 867-878, Время-проекционная камера детектора MPD на коллайдерном комплексе NICA, А.В. Аверьянов, А.Г. Бажажин, и др., http://elibrary.ru/item.asp?id=20991936.

         Описание проекта

        Целью проекта является расчет (моделирование) неоднородности электрического (электростатического) поля внутри TPC, которую можно разбить на следующие пункты:

1. Рассчитать с помощью 2D и 3D моделирования электрическое поле (линии напряжённости электростатического поля) внутри TPC, используя программный пакет ANSYS Maxwell и по возможности Garfield. Визуализировать промоделированное электрическое поле внутренней части TPC в 2D и 3D виде (сделать чертежи конструкции TPC и электрического поля рабочего объёма) в какой-нибудь из двух (или в обоих) программных пакетов (ANSYS Maxwell и Garfield).

2. Сравнить рассчитанные величины и визуализацию электрического поля внутри TPC с посчитанными ранее аналогичными значениями и рисунками.

3. Рассчитать и представить детальную визуализацию электрического поля внутри ROC камеры TPC, формирующегося с учётом проволочных плоскостей с поданными на них соответствующими напряжениями.

4. Провести (рассчитать) оптимизацию величины напряжения на первом и последнем электроде системы полеформирующих электродов (field cage) путем минимизации искажения формы электрического поля внутри TPC. Проделать аналогичные расчёты для вторых электродов системы field cage, если совсем убрать первые (предыдущие) электроды.

5. Рассчитать влияние объёмного заряда положительных ионов на форму электрического поля внутри TPC в зависимости от его величины.

P.S.: Допускается сделать только часть пунктов за время летней студенческой программы ОИЯИ.


          Требования к кандидатам:

      Иметь опыт работы с чертёжными и/или расчётными программами для моделирования. Владеть программным пакетом ANSYS Maxwell или/и Garfield, либо уметь относительно быстро осваивать подобные программы.

          Руководители проектов:

начальник сектора НЭОМД (MPD) ЛФВЭ к.ф.-м.н. Мовчан С.А.,
e
-mail: movchansa@yandex.ru, раб./тел.: +7-49621-65933;

научный сотрудник НЭОМД (MPD) ЛФВЭ Бажажин А.Г.,
e-mail:
albazhazhin@mail.ru, раб./тел.: +7-49621-64142.

Description:

Overview

Our group is involved in two neutrino oscillation experiments with reactor electron antineutrinoes: the currently running Daya Bay experiment (data analysis) and currently prepared JUNO experiment. Both experiments are based in China.

Our work includes:
  • Neutrino oscillation parameters determination and search for non-standard oscillation effects in the Daya Bay experiment.
  • Reactor antineutrino flux measurement in the Daya Bay experiment.
  • Determination of the neutrino oscillation parameters and neutrino mass hierarchy in JUNO experiment (future). Experiment sensitivity study.
  • Study of the optical parameters of the large Photomultiplier tubes (PMT) for JUNO experiment. Study of the impact of the PMT response on the JUNO performance.
We are doing the analysis in our own software and our tasks are closely connected to both physics and programming.


Daya Bay 

Daya Bay neutrino experiment is the first medium base experiment to observe reactor electron antineutrino disappearance with significance higher than 5 standard deviations and is the first reactor experiment to measure mass splitting Δm²₃₂. Daya Bay has measured antineutrino mixing angle θ₁₃ with unprecedented precision.
 
Antineutrino flux from 6 nuclear reactors with a total nominal thermal power of 17.4 GW is observed by 8 identically designed 20 kt liquid scintillator detectors. Experimental halls located on average distances of 500 m, 600 m and 1.5 km from the reactors see slightly different antineutrino flux due to oscillations. The comparison of the observed antineutrino spectrum between far and near detectors gives a flux model independent handle to measure oscillation parameters. The ratio of the total number of events is related mostly to the oscillation amplitude sin²2θ₁₃ while relative spectral distortion is almost exclusively determined by mass splitting.
 
Other goals of the experiment include the measurement of the reactor antineutrino flux and spectrum, sterile neutrino search, new physics and non-standard interactions searches.
 

JUNO
 
Jiangmen Underground Neutrino Observatory — is planned new generation precision experiment with reactor electron antineutrinos, proposed to determine the neutrino mass hierarchy. 
 
JUNO detector will have spherical shape with diameter of 35 m filled by 20 kt liquid scintillator and equipped by 20 000 photomultiplier tubes installed with almost maximal geometrical coverage. Such a coverage is needed in order to maximize the light efficiency and reach unprecedented energy resolution of 3% at 1 MeV.
 
The detector will be installed on a distance of 52 km from Yangjiang and Taishan nuclear power plants. On this baseline the observed antineutrino spectrum will be heavily distorted by neutrino oscillations: the spectrum itself will have fine oscillations with period of order of hundreds of keV. Given the energy resolution of 3% the measurement of the period and phase of these fine oscillations is a handle to precisely measure neutrino mass splitting Δm²₃₂. More important, JUNO will be able to determine the sign of Δm²₃₂ with significance higher than 3 standard deviations within 6 years after starting the data taking in 2020. The determination of the mass splitting sign is equivalent to the measuring the mass hierarchy: normal hierarchy means that third neutrino mass state is heavier than first and second, while for inverted hierarchy the third neutrino mass state is the lightest.
 
Apart from Δm²₃₂ JUNO will be able to measure other oscillation parameters Δm²₂₁ и θ₁₂ with precision better than 1%. The experiment will be also sensitive to the signals of atmospheric neutrino, geo-neutrino and supernova neutrino.
 
 
Summer program tasks include
 
1) First task for the summer program is concerned with our own software Global Neutrino Analysis (GNA), intended for the statistical analysis of the data of neutrino experiments (reactor, accelerator and atmospheric). The plan includes the improvement of the module for the statistical analysis via Feldman-Cousins method (as described in the thesis by Taichenachev in 'Other reading'). This is very computationally intense procedure and will greatly benefit if defined in parallel way. Of course this is preliminary and quite difficult task that may be modified during the summer program.

2) Second task is also connected with GNA software and is concerned with implemntation of laternative statistical tests: poisson likelihood function, CLs method, etc.

3) Third task is concerned with analytical and numerical study of the PMT efficiency for the JUNO experiment.

Other reading

The scope of the current work of our group may be determined from 
 
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