Transcript Document

XIII International Symposium on
Very High Energy Cosmic Ray
Interactions
Pylos, 6 -12 September 2004
The Modern Concept
of the INCA Project
Direct Studies of
Primary protons and nuclei
in the “knee” range
R.A. Mukhamedshin
Institute for Nuclear Research, Moscow, Russia
for the INCA Collaboration
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The INCA Project – Collaboration Members
The INCA Collaboration
V.V.Ammosov1, V.P.Antonova2, G.I. Britvich1, A.P.Chubenko3, V.I.Drobzhev2,
A.D.Erlykin3, G.I. Kol'tsov4, S.V. Kryukov2, G.I. Merzon3, K.K. Mukashev5,
R.A. Mukhamedshin6, V.N.Murashev4, V.P. Pavlyuchenko3, V.A.Ryabov3,
O.G.Ryazhskaya6, T. Saito7, A.L.Shchepetov3, N.M. Sobolevskii6,
A.P. Soldatov1, V.M. Sultangazin8, I.S.Trostin9, G.T. Zatsepin6, A.P. Zhukov6
1.
2.
3.
4.
5.
6.
7.
8.
9.
Institute of High-Energy Physics, Protvino, Russia
Institute of Ionosphere, Almaty, Kazakhstan
Lebedev Physical Institute, Moscow, Russia
Institute of Steel and Alloys, Moscow, Russia
Abai Almaty State University, Almaty, Kazakhstan Republic
Institute for Nuclear Research, Moscow, Russia
Institute for Advanced Studies, Tokyo, 162-0022 Japan
Institute for Cosmic Research, Almaty, Kazakhstan Republic
Institute for Theoretical and Experimental Physics, Moscow, Russia
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The INCA Project - Introduction
The “knee” problem
 is very important for astrophysics and, may be, physics of
strong interactions
 no unambiguious conclusion on CR spectrum, composition,
and, may be, physics
 no direct measurements at E0> 1015 eV
 heavy-material calorimeters are unusable due to
• small acceptance SW (  0.3 m2sr for Protons);
• intense back current
To solve the “knee” problem,
• large acceptance ( » 1 m2sr)
• long-duration exposure ( > 1 year )
• new approach to energy measurements
are required for calorimetric technique
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The INCA Project - Objectives
Main Scientific Objectives
• The spectum & composition of primary cosmic
radiation in the "knee" range (E0 ~ 1015 – 1016 eV);
•
•
•
•
spectrum of primary electrons at E0 ~ 1012 - 1013 eV;
neutrons & g-rays from solar flares;
diffusive g-radiation at E0 ~ 0.010 - 1 TeV;
by-product searches for
• very massive exotic particles with abnormally low charge-tomass ratio (strangelets ?);
• interactions with abnormally high hadron-to-g-ray ratio
(“Centauros” ?)
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The INCA Project - Potentialities
Expected number of events
detected during 2-3-year exposition :
• Number of primary nuclei
• N(E0 > 1015 eV) ~ 2000 - 6000 events;
• N(E0 > 1016 eV) ~
40 - 120 events.
• Number of primary electrons:
• N(E0 > 1012 eV) = 2000 - 6000 events
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The INCA Project - Theoretical foundations
Main ideas
• light-substance Ionization-Neutron CAlorimeter
• measurement of the energy of primary nuclei by
two independent techniques with:
• counting mode for the thermalized-neutron yield;
• amplitude measuring mode for the ionization signal
• development and use of newest high-tech detector
technologies
• selection of primary electrons against the protons by
counting neutrons
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The INCA Project - Satellite
• Dimensions = 2 x 2 x 2 m3
• 4p geometry
• Four-dimension cascade picture
(x,y,z,t)
• SW = 48 m2sr
• Weight = 10 t
• Thickness
• 4.6 l int (at E0~1015 eV)
• 13 radiation lengths
• 50 layers
• Number of channels
• 40 per layer
• 2000 in total
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The INCA Project - The INCA satellite project
• semiconductor charge
detector
• Plastic scintillator+lead for gray selection
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The INCA Project - Detectors
Plastic scintillators
• newly developed (IHEP, Protvino) and enriched by
orthocarborane (2-3%) to detect thermalized neutrons;
• Used to measure both the neutron and ionization signals;
• Reactions used for neutron counting:
• n + 10B  4a + 7Li*
(94%):
7Li
+g
• Additionally measured yield of delayed g-rays
• n + p  d + g (2.2 MeV)
• n + Fe  g + . . .
• n + Cd  g + . . .
• n + Gd  g + . . .
A part of these
reactions
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The INCA Project - Detectors
Reactions under consideration:
n + 10B  4a + 7Li*
7Li
g from
neutron
source
+g
ionization
by a
a) Experimental data on neutron detection by a version of scintillation detectors;
b) sketch of amplitudes of signals of different origin
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The INCA Project - Theoretical foundations - Simulations
Energy measurement by evaporated-neutron signal
• Yield of neutrons is proportional to the primary energy
• Energy dependence of neutron yield is near linear up to energies of
the “knee” range
• Neutron yield at “knee” energies is ~ 106 and long-term (> 100 ms)
1000000
100000
10000
Cascade
length,
g/cm2
primary p
500
400
300
200
100
<nneut>
1000
100
10
0,01
0,1
1
10
E0, TeV
100
1000
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The INCA Project - Theoretical foundations - Simulations
Fluctuations of neutron yield
• Standard deviation of neutron yield at effective depth ~250 g/cm2 is
• ~ 0,30 in proton-induced cascades
• < 0,25 in nucleus-induced cascades
• Standard deviation in charged-particle flow is of the same order
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The INCA Project - Detectors
Photo detectors
• vacuum phototriodes
• newly developed plastic photo-sensitive plates;
• PMTs to detect single-neutron capture in plastic scintillators
Requirements
• wide dynamical range (~ 107);
• threshold sensitivity is about 20 MIPs (sufficient at E0>1015 eV)
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The INCA Project - Detectors
Semiconductor counters
• New high-tech detectors of
future generation
• new-concept pixel silicon
detectors with a high spacetime resolution are designed
• local-injection mechanism for
the amplification by bipolartransistor structure of the
drift component of the
ionization current produced by
relativistic charged particle is
exploited
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The INCA Project - Detectors
•
different combination of pixels
to reach required properties of
the detectors.
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The INCA Project - Detectors
• Step-by-step transfer of
non-basic current carriers
along the transistor-cell
chain occurs;
• matrix-structure detector
containing a large number
of cells (n-p-n transistors)
deposited on a silicon
substrate is applied;
• DNA molecule-like celldoubling principle is
realized in the matrix
structure
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The INCA Project - Detectors
Experimental samples of new-concept pixel silicon bipolar
detectors
The use of new-concept pixel silicon bipolar detectors as
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photodetectors is analyzed
The INCA Project
Summary
• A high-technology project with unique scientific objectives and
potentialities is under elaboration
• A new effective technique for direct investigations of the PCR
spectrum in the "knee" range at E0 > 1015 eV is developed.
• A state-of-the-art technology for investigation of primary cosmic
radiation is under elaboration
The INCA Project is open for the international community!
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Collaborators are welcome!
Thank you!
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The INCA Project – Main Guidelines and Problems of INCA Design
Stage 1. Design and testing of technological elements
• Scintillators
• Phototriodes
• Plastic photo-sensitive plates
• Pixel silicon bipolar transistor detectors
• Simulations
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The INCA Project – Main Guidelines and Problems of INCA Design
Stage 2. Construction of apparatus modules
• Main Calorimeter
• Charge detectors
• Reading and processing systems
• Electronics
• Data processing algorithms
Stage 3. Testing of apparatus modules
• Accelerator experiments
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The INCA Project – Collaboration
Possible directions of collaboration
• Production of pixel silicon bipolar transistor detectors
• Development of reading and processing systems
• Development of electronics
• Construction and launching of joint balloon equipment for
•
Testing the systems
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Study of electron primary spectrum at E0 > 1 TeV
• Submitting joint applications for financial support of joint investigations
into CRDF (Civilian Reseach & Development Foundation), ISTC
(International Science & Technology Center), INTAS etc.
• Satellite ?
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The INCA Project – Technological Elements of INCA Design
Scintillators:
• already developed
• cost:
~ 75 $ /1 kg (or less)
• specific configurations can be produced at any time
• arbitrary configurations can be produced if a corresponding mold is
constructed
Stage 1
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The INCA Project – Technological Elements of INCA Design
Phototriodes:
• already developed
• cost:
~ 30 $ each
• can be produced at any time
Plastic photo-sensitive plates
• already developed
• cost:
~ 1 $ /1 cm2
• can be produced at any time
Stage 1
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The INCA Project – Technological Elements of INCA Design
Pixel silicon bipolar transistor detectors:
• the most interesting and promising detectors of the next generation
• know-how is patented
• developed least of all
• cost: ~ 30 - 200 $ /1 dm2 (depends on silicon base purity)
• features are strongly dependent on
• silicon quality
• quality of spatial technology resolution (~ 1 m2 is required for
~102-amplification by one pixel)
• it seems that detectors with a very good features cannot be
produced in Russia: the most promising direction of a collaboration
Stage 1
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The INCA Project - Theoretical foundations – Simulations
Basic codes
• The MC0 code of strong interactions (usable up to ~1018 eV)
and package SHIELD are used for simulations
• The MC0 code is based on:
• data by accelerator experiments
• Quark-Gluon String model by Yu.Shabelsky
• Semi-hard jet theory by Gribov-Levin-Ryskin
• The MC0 code describes rather well
• accelerator data
• data on g-h families observed in X-ray emulsion chamber experiments
• The neutron-transport package SHIELD is :
• based on data by accelerator and neutron experiments
• specially designed for neutron investigations
Stage 1
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The INCA Project - Theoretical foundations - Simulations
The QGSM-based MC0 code (close to QGSJET) realizes
• Hadron interactions as
• soft hadron interactions
• semi-hard and hard jet generation
• diffraction processes
• generation of stable and resonance baryons and mesons, including
charm and strange particles
• Electromagnetic cascade with accounting for
• pair generation
• bremsstrahlung
• multiple Coulomb scattering
• Compton scattering
• ionization losses
• inelastic photonuclear interactions of g-rays
• LPM effect at high energies
• giant resonance absorption of low-energy g-rays
Stage 1
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The INCA Project - Theoretical foundations - Simulations
The MC0 code realizes generation of neutrons as
• neutron evaporation by nuclei excited due to
• hadron interactions
• inelastic photonuclear interactions of g-rays;
• absorption of low-energy photons in giant resonance processes;
• neutron generation in hadron cascade interactions
Stage 1
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The INCA Project - Theoretical foundations - Simulations
Notes:
• Only the neutron generation is mainly considered, not neutron history
• Such factors as
• neutron thermalization and diffusion
• real geometry
• apparatus response
• role of the primary spectrum
will be carried out in the nearest future
Stage 1
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The INCA Project - Theoretical foundations - Simulations
Prototype simulations
• a setup 500-g/cm2 thick (~7 lint ) with a periodic structure is considered
• each of layers consists of lead and a light substance (polyethylene, e.g.)
•
lead layer: 10 g/cm2 (~1.5 rad. length, ~1/20 lint )
•
polyethylene layer: 20 g/cm2 (~0.5 rad. length, ~1/4 lint )
Stage 1
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