Applications of neutron spectrometry

Neutron sources 1) Reactors 2) Usage of reactions 3) Spallation sources

Neutron show 1) Where atoms are (structure) ndash elastic scattering 2) What they are doing (dynamics) ndash inelastic scattering

Neutron diffraction is not useful for highly absorbing materials Gd Sm Eu Cd B Dy

Photon diffraction dos not distinguish different isotopes neutron can distinguish

1) Introduction2) Research3) Application

GELINA TOF spectrometer(Belgium)

Usage of neutrons at applications

Research of neutron production and transport at different processes

Probe to behavior of nuclei history of spallation reactions and properties of nuclear matter

Neutron diffractometry

Usage of inelastic neutron scattering

Material research ndash different physical properties

Crystalography ndash structure of crystals

Advantage 1) see light elements 2) discriminates near elements and isotopes 3) Study of structure properties of large composite samples 4) Study of magnetic properties 5) Possibility of material research also after thick wall

Smallangle neutron scattering structures o 1 ndash 1000 nm sizes ndash sensitive to light elements

focussing difraktometr

Measurement of changes of lattice constant of polycrystalic structures measurement of micro a macro deformation (study of different type of steels )

Possibility of material research at breaker laboratory furnace

anisotropy of grains orientation at polycrystallic structures ndash influence on rigidity and further properties

Spallation reactions as intensive source of neutrons

Reaction of protons with high energies ( gt 100 MeV ) with nuclei

Very intensive source of neutrons ndash it is possible obtain flux 1016ncm2s

Three phases of spallation reaction

1) Intranuclear cascade - incident proton kicks off in nucleon-nucleon collisions with nucleons with high energies 2) Preequilibrium emission ndash escape of nucleons with higher energy from nucleus before thermal equilibrium restoration3) Evaporation of neutrons or nucleus fission ndash nucleus in thermal equilibrium unloads surplus energy by evaporation of neutrons with energy about 5 MeV Neutrons are evaporated also by fission fragments

High energy nucleons created during intranuclear cascade can produce further spallation reactions - hadron shower

This condition is necessary for efective transmutation

Cross sections for ADTT systems and astrophysics

Facility n-TOF at CERN

Lead target ndash spallation reaction

Proton beam Ep = 20 GeV Δt = 7 ns I = 71012 protons f = 08 Hz

distance 185 m 105 npulsenergy order

neutron beam with FWHM = 118 mm

neutron beam 300 np En = 01 eV ndash 250 MeV

Shielding after target deflection magnet

lead target - assembling

special collimation and moderation for different work regime

Number of fission reaction of 235U as dependency on neutron energy

Spectrum of produced neutrons (simulation)(on the end of transport system - 185 m from the target)

Energy resolution of n-TOF facilityResonance 808 keV at Fe

Measurement of capture on 151Sm

Course of reaction and branch of s-processin the range of Gd Eu a Sm

Detection of gamma by means C6D6 scintillator(small sensitivity on neutrons)

Neutrons with energy from 06 eV up to 1 MeV

Accuracy 6

1) Half-life is 93 years ndash component of nuclear power station waste

Study of reaction (nγ) on 151Sm

2) Important part of sequence of noble earths production

3) Belongs to transition elements

neutronbeam

gamma detection system

background

Range 500 ndash 550 eV

Production of neutrons by spallation reactions and collisions of protons and heavy ions

Production of neutrons on uranium Ep = 585 MeV (S Cierjacks Phys Rev 36(1987)1976

Proton beam from cyclotrone at SIN (Switzerland) is used ndash pulse 200 ps

Thin targetsholes (d=4cm) in 20 cm of iron rarrnarrowly collimated neutron beamto angles 30o 90o and 150o

NE213 ndash neutron detectorNE102A ndash veto detector ndash suppression of charged particles

1) Example of measurement of neutron production by spallation reactions on thin targets

target ndash detector distance is 13 m

Energy resolution

2) Measurement of neutron production by spallation reactions to zero angle

Deflection of beam of charged protons and other particles by magnet

Choice only of forward protons produced by neutron collisions (head on collision rarr total neutron energy is transferred

Problems 1) inelastic processes at convertor n + p rarr p + n + π0 n + p rarr p + p + π-

2) production of other particles n + p rarr d + π0 n + p rarr d + γ 3) background of particles produced in other places 4) accuracy of knowledge of np scattering cross- section as function of energy

convertor (liquid hydrogen) ndash 093 gcm2

spectrometer 4 multiwire proportional chambers 2 before and 2 after magnet (determination of momentum)

Proton beam at LAMPF (USA) E = 800 MeV

important materials Al Ti Cu W Pb U

Many further experiments studying production of neutrons at spallation reactions and heavy ion collisions

Similarly also neutron production on heavy targets

3) Measurement of neutron production on thick targets or complicated set-ups

Purpose to obtain data about neutron production and transport for benchmark of simulation codes

Set-up of lead target and uranium blanket

Determination of neutron fluencies and spectra by activation method

Display of set-up by simulation code MCNPX

Example Set-up bdquoEnergy plus Transmutationldquo at JINR Dubna

Accelerator Nuclotron

Activation foils and track detectors

Obtained experimental data

Longitudinal distribution Radial distributionEp = 15 GeV

Measured data number of produced nuclei at activation sample normalized on proton and gram of sample

Example of data spatial distribution of neutron fluencies

Such data can be directly compared with simulations

Position along the target [cm] Radial distance [cm]

Radial direction

0

1

2

3

4

5

6

0 5 10 15

r [cm]

EX

PC

EM

24Na

196Au

194Au

206Bi

58Co6 MeV

8 MeV

11 MeV23 MeV 23 MeV

Comparison of experimental data and simulations by means of MCNPX

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10

Neutron diffractometry

Usage of inelastic neutron scattering

Material research ndash different physical properties

Crystalography ndash structure of crystals

Advantage 1) see light elements 2) discriminates near elements and isotopes 3) Study of structure properties of large composite samples 4) Study of magnetic properties 5) Possibility of material research also after thick wall

Smallangle neutron scattering structures o 1 ndash 1000 nm sizes ndash sensitive to light elements

focussing difraktometr

Measurement of changes of lattice constant of polycrystalic structures measurement of micro a macro deformation (study of different type of steels )

Possibility of material research at breaker laboratory furnace

anisotropy of grains orientation at polycrystallic structures ndash influence on rigidity and further properties

Spallation reactions as intensive source of neutrons

Reaction of protons with high energies ( gt 100 MeV ) with nuclei

Very intensive source of neutrons ndash it is possible obtain flux 1016ncm2s

Three phases of spallation reaction

1) Intranuclear cascade - incident proton kicks off in nucleon-nucleon collisions with nucleons with high energies 2) Preequilibrium emission ndash escape of nucleons with higher energy from nucleus before thermal equilibrium restoration3) Evaporation of neutrons or nucleus fission ndash nucleus in thermal equilibrium unloads surplus energy by evaporation of neutrons with energy about 5 MeV Neutrons are evaporated also by fission fragments

High energy nucleons created during intranuclear cascade can produce further spallation reactions - hadron shower

This condition is necessary for efective transmutation

Cross sections for ADTT systems and astrophysics

Facility n-TOF at CERN

Lead target ndash spallation reaction

Proton beam Ep = 20 GeV Δt = 7 ns I = 71012 protons f = 08 Hz

distance 185 m 105 npulsenergy order

neutron beam with FWHM = 118 mm

neutron beam 300 np En = 01 eV ndash 250 MeV

Shielding after target deflection magnet

lead target - assembling

special collimation and moderation for different work regime

Number of fission reaction of 235U as dependency on neutron energy

Spectrum of produced neutrons (simulation)(on the end of transport system - 185 m from the target)

Energy resolution of n-TOF facilityResonance 808 keV at Fe

Measurement of capture on 151Sm

Course of reaction and branch of s-processin the range of Gd Eu a Sm

Detection of gamma by means C6D6 scintillator(small sensitivity on neutrons)

Neutrons with energy from 06 eV up to 1 MeV

Accuracy 6

1) Half-life is 93 years ndash component of nuclear power station waste

Study of reaction (nγ) on 151Sm

2) Important part of sequence of noble earths production

3) Belongs to transition elements

neutronbeam

gamma detection system

background

Range 500 ndash 550 eV

Production of neutrons by spallation reactions and collisions of protons and heavy ions

Production of neutrons on uranium Ep = 585 MeV (S Cierjacks Phys Rev 36(1987)1976

Proton beam from cyclotrone at SIN (Switzerland) is used ndash pulse 200 ps

Thin targetsholes (d=4cm) in 20 cm of iron rarrnarrowly collimated neutron beamto angles 30o 90o and 150o

NE213 ndash neutron detectorNE102A ndash veto detector ndash suppression of charged particles

1) Example of measurement of neutron production by spallation reactions on thin targets

target ndash detector distance is 13 m

Energy resolution

2) Measurement of neutron production by spallation reactions to zero angle

Deflection of beam of charged protons and other particles by magnet

Choice only of forward protons produced by neutron collisions (head on collision rarr total neutron energy is transferred

Problems 1) inelastic processes at convertor n + p rarr p + n + π0 n + p rarr p + p + π-

2) production of other particles n + p rarr d + π0 n + p rarr d + γ 3) background of particles produced in other places 4) accuracy of knowledge of np scattering cross- section as function of energy

convertor (liquid hydrogen) ndash 093 gcm2

spectrometer 4 multiwire proportional chambers 2 before and 2 after magnet (determination of momentum)

Proton beam at LAMPF (USA) E = 800 MeV

important materials Al Ti Cu W Pb U

Many further experiments studying production of neutrons at spallation reactions and heavy ion collisions

Similarly also neutron production on heavy targets

3) Measurement of neutron production on thick targets or complicated set-ups

Purpose to obtain data about neutron production and transport for benchmark of simulation codes

Set-up of lead target and uranium blanket

Determination of neutron fluencies and spectra by activation method

Display of set-up by simulation code MCNPX

Example Set-up bdquoEnergy plus Transmutationldquo at JINR Dubna

Accelerator Nuclotron

Activation foils and track detectors

Obtained experimental data

Longitudinal distribution Radial distributionEp = 15 GeV

Measured data number of produced nuclei at activation sample normalized on proton and gram of sample

Example of data spatial distribution of neutron fluencies

Such data can be directly compared with simulations

Position along the target [cm] Radial distance [cm]

Radial direction

0

1

2

3

4

5

6

0 5 10 15

r [cm]

EX

PC

EM

24Na

196Au

194Au

206Bi

58Co6 MeV

8 MeV

11 MeV23 MeV 23 MeV

Comparison of experimental data and simulations by means of MCNPX

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10

Spallation reactions as intensive source of neutrons

Reaction of protons with high energies ( gt 100 MeV ) with nuclei

Very intensive source of neutrons ndash it is possible obtain flux 1016ncm2s

Three phases of spallation reaction

1) Intranuclear cascade - incident proton kicks off in nucleon-nucleon collisions with nucleons with high energies 2) Preequilibrium emission ndash escape of nucleons with higher energy from nucleus before thermal equilibrium restoration3) Evaporation of neutrons or nucleus fission ndash nucleus in thermal equilibrium unloads surplus energy by evaporation of neutrons with energy about 5 MeV Neutrons are evaporated also by fission fragments

High energy nucleons created during intranuclear cascade can produce further spallation reactions - hadron shower

This condition is necessary for efective transmutation

Cross sections for ADTT systems and astrophysics

Facility n-TOF at CERN

Lead target ndash spallation reaction

Proton beam Ep = 20 GeV Δt = 7 ns I = 71012 protons f = 08 Hz

distance 185 m 105 npulsenergy order

neutron beam with FWHM = 118 mm

neutron beam 300 np En = 01 eV ndash 250 MeV

Shielding after target deflection magnet

lead target - assembling

special collimation and moderation for different work regime

Number of fission reaction of 235U as dependency on neutron energy

Spectrum of produced neutrons (simulation)(on the end of transport system - 185 m from the target)

Energy resolution of n-TOF facilityResonance 808 keV at Fe

Measurement of capture on 151Sm

Course of reaction and branch of s-processin the range of Gd Eu a Sm

Detection of gamma by means C6D6 scintillator(small sensitivity on neutrons)

Neutrons with energy from 06 eV up to 1 MeV

Accuracy 6

1) Half-life is 93 years ndash component of nuclear power station waste

Study of reaction (nγ) on 151Sm

2) Important part of sequence of noble earths production

3) Belongs to transition elements

neutronbeam

gamma detection system

background

Range 500 ndash 550 eV

Production of neutrons by spallation reactions and collisions of protons and heavy ions

Production of neutrons on uranium Ep = 585 MeV (S Cierjacks Phys Rev 36(1987)1976

Proton beam from cyclotrone at SIN (Switzerland) is used ndash pulse 200 ps

Thin targetsholes (d=4cm) in 20 cm of iron rarrnarrowly collimated neutron beamto angles 30o 90o and 150o

NE213 ndash neutron detectorNE102A ndash veto detector ndash suppression of charged particles

1) Example of measurement of neutron production by spallation reactions on thin targets

target ndash detector distance is 13 m

Energy resolution

2) Measurement of neutron production by spallation reactions to zero angle

Deflection of beam of charged protons and other particles by magnet

Choice only of forward protons produced by neutron collisions (head on collision rarr total neutron energy is transferred

Problems 1) inelastic processes at convertor n + p rarr p + n + π0 n + p rarr p + p + π-

2) production of other particles n + p rarr d + π0 n + p rarr d + γ 3) background of particles produced in other places 4) accuracy of knowledge of np scattering cross- section as function of energy

convertor (liquid hydrogen) ndash 093 gcm2

spectrometer 4 multiwire proportional chambers 2 before and 2 after magnet (determination of momentum)

Proton beam at LAMPF (USA) E = 800 MeV

important materials Al Ti Cu W Pb U

Many further experiments studying production of neutrons at spallation reactions and heavy ion collisions

Similarly also neutron production on heavy targets

3) Measurement of neutron production on thick targets or complicated set-ups

Purpose to obtain data about neutron production and transport for benchmark of simulation codes

Set-up of lead target and uranium blanket

Determination of neutron fluencies and spectra by activation method

Display of set-up by simulation code MCNPX

Example Set-up bdquoEnergy plus Transmutationldquo at JINR Dubna

Accelerator Nuclotron

Activation foils and track detectors

Obtained experimental data

Longitudinal distribution Radial distributionEp = 15 GeV

Measured data number of produced nuclei at activation sample normalized on proton and gram of sample

Example of data spatial distribution of neutron fluencies

Such data can be directly compared with simulations

Position along the target [cm] Radial distance [cm]

Radial direction

0

1

2

3

4

5

6

0 5 10 15

r [cm]

EX

PC

EM

24Na

196Au

194Au

206Bi

58Co6 MeV

8 MeV

11 MeV23 MeV 23 MeV

Comparison of experimental data and simulations by means of MCNPX

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10

Cross sections for ADTT systems and astrophysics

Facility n-TOF at CERN

Lead target ndash spallation reaction

Proton beam Ep = 20 GeV Δt = 7 ns I = 71012 protons f = 08 Hz

distance 185 m 105 npulsenergy order

neutron beam with FWHM = 118 mm

neutron beam 300 np En = 01 eV ndash 250 MeV

Shielding after target deflection magnet

lead target - assembling

special collimation and moderation for different work regime

Number of fission reaction of 235U as dependency on neutron energy

Spectrum of produced neutrons (simulation)(on the end of transport system - 185 m from the target)

Energy resolution of n-TOF facilityResonance 808 keV at Fe

Measurement of capture on 151Sm

Course of reaction and branch of s-processin the range of Gd Eu a Sm

Detection of gamma by means C6D6 scintillator(small sensitivity on neutrons)

Neutrons with energy from 06 eV up to 1 MeV

Accuracy 6

1) Half-life is 93 years ndash component of nuclear power station waste

Study of reaction (nγ) on 151Sm

2) Important part of sequence of noble earths production

3) Belongs to transition elements

neutronbeam

gamma detection system

background

Range 500 ndash 550 eV

Production of neutrons by spallation reactions and collisions of protons and heavy ions

Production of neutrons on uranium Ep = 585 MeV (S Cierjacks Phys Rev 36(1987)1976

Proton beam from cyclotrone at SIN (Switzerland) is used ndash pulse 200 ps

Thin targetsholes (d=4cm) in 20 cm of iron rarrnarrowly collimated neutron beamto angles 30o 90o and 150o

NE213 ndash neutron detectorNE102A ndash veto detector ndash suppression of charged particles

1) Example of measurement of neutron production by spallation reactions on thin targets

target ndash detector distance is 13 m

Energy resolution

2) Measurement of neutron production by spallation reactions to zero angle

Deflection of beam of charged protons and other particles by magnet

Choice only of forward protons produced by neutron collisions (head on collision rarr total neutron energy is transferred

Problems 1) inelastic processes at convertor n + p rarr p + n + π0 n + p rarr p + p + π-

2) production of other particles n + p rarr d + π0 n + p rarr d + γ 3) background of particles produced in other places 4) accuracy of knowledge of np scattering cross- section as function of energy

convertor (liquid hydrogen) ndash 093 gcm2

spectrometer 4 multiwire proportional chambers 2 before and 2 after magnet (determination of momentum)

Proton beam at LAMPF (USA) E = 800 MeV

important materials Al Ti Cu W Pb U

Many further experiments studying production of neutrons at spallation reactions and heavy ion collisions

Similarly also neutron production on heavy targets

3) Measurement of neutron production on thick targets or complicated set-ups

Purpose to obtain data about neutron production and transport for benchmark of simulation codes

Set-up of lead target and uranium blanket

Determination of neutron fluencies and spectra by activation method

Display of set-up by simulation code MCNPX

Example Set-up bdquoEnergy plus Transmutationldquo at JINR Dubna

Accelerator Nuclotron

Activation foils and track detectors

Obtained experimental data

Longitudinal distribution Radial distributionEp = 15 GeV

Measured data number of produced nuclei at activation sample normalized on proton and gram of sample

Example of data spatial distribution of neutron fluencies

Such data can be directly compared with simulations

Position along the target [cm] Radial distance [cm]

Radial direction

0

1

2

3

4

5

6

0 5 10 15

r [cm]

EX

PC

EM

24Na

196Au

194Au

206Bi

58Co6 MeV

8 MeV

11 MeV23 MeV 23 MeV

Comparison of experimental data and simulations by means of MCNPX

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10

Number of fission reaction of 235U as dependency on neutron energy

Spectrum of produced neutrons (simulation)(on the end of transport system - 185 m from the target)

Energy resolution of n-TOF facilityResonance 808 keV at Fe

Measurement of capture on 151Sm

Course of reaction and branch of s-processin the range of Gd Eu a Sm

Detection of gamma by means C6D6 scintillator(small sensitivity on neutrons)

Neutrons with energy from 06 eV up to 1 MeV

Accuracy 6

1) Half-life is 93 years ndash component of nuclear power station waste

Study of reaction (nγ) on 151Sm

2) Important part of sequence of noble earths production

3) Belongs to transition elements

neutronbeam

gamma detection system

background

Range 500 ndash 550 eV

Production of neutrons by spallation reactions and collisions of protons and heavy ions

Production of neutrons on uranium Ep = 585 MeV (S Cierjacks Phys Rev 36(1987)1976

Proton beam from cyclotrone at SIN (Switzerland) is used ndash pulse 200 ps

Thin targetsholes (d=4cm) in 20 cm of iron rarrnarrowly collimated neutron beamto angles 30o 90o and 150o

NE213 ndash neutron detectorNE102A ndash veto detector ndash suppression of charged particles

1) Example of measurement of neutron production by spallation reactions on thin targets

target ndash detector distance is 13 m

Energy resolution

2) Measurement of neutron production by spallation reactions to zero angle

Deflection of beam of charged protons and other particles by magnet

Choice only of forward protons produced by neutron collisions (head on collision rarr total neutron energy is transferred

Problems 1) inelastic processes at convertor n + p rarr p + n + π0 n + p rarr p + p + π-

2) production of other particles n + p rarr d + π0 n + p rarr d + γ 3) background of particles produced in other places 4) accuracy of knowledge of np scattering cross- section as function of energy

convertor (liquid hydrogen) ndash 093 gcm2

spectrometer 4 multiwire proportional chambers 2 before and 2 after magnet (determination of momentum)

Proton beam at LAMPF (USA) E = 800 MeV

important materials Al Ti Cu W Pb U

Many further experiments studying production of neutrons at spallation reactions and heavy ion collisions

Similarly also neutron production on heavy targets

3) Measurement of neutron production on thick targets or complicated set-ups

Purpose to obtain data about neutron production and transport for benchmark of simulation codes

Set-up of lead target and uranium blanket

Determination of neutron fluencies and spectra by activation method

Display of set-up by simulation code MCNPX

Example Set-up bdquoEnergy plus Transmutationldquo at JINR Dubna

Accelerator Nuclotron

Activation foils and track detectors

Obtained experimental data

Longitudinal distribution Radial distributionEp = 15 GeV

Measured data number of produced nuclei at activation sample normalized on proton and gram of sample

Example of data spatial distribution of neutron fluencies

Such data can be directly compared with simulations

Position along the target [cm] Radial distance [cm]

Radial direction

0

1

2

3

4

5

6

0 5 10 15

r [cm]

EX

PC

EM

24Na

196Au

194Au

206Bi

58Co6 MeV

8 MeV

11 MeV23 MeV 23 MeV

Comparison of experimental data and simulations by means of MCNPX

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10

Measurement of capture on 151Sm

Course of reaction and branch of s-processin the range of Gd Eu a Sm

Detection of gamma by means C6D6 scintillator(small sensitivity on neutrons)

Neutrons with energy from 06 eV up to 1 MeV

Accuracy 6

1) Half-life is 93 years ndash component of nuclear power station waste

Study of reaction (nγ) on 151Sm

2) Important part of sequence of noble earths production

3) Belongs to transition elements

neutronbeam

gamma detection system

background

Range 500 ndash 550 eV

Production of neutrons by spallation reactions and collisions of protons and heavy ions

Production of neutrons on uranium Ep = 585 MeV (S Cierjacks Phys Rev 36(1987)1976

Proton beam from cyclotrone at SIN (Switzerland) is used ndash pulse 200 ps

Thin targetsholes (d=4cm) in 20 cm of iron rarrnarrowly collimated neutron beamto angles 30o 90o and 150o

NE213 ndash neutron detectorNE102A ndash veto detector ndash suppression of charged particles

1) Example of measurement of neutron production by spallation reactions on thin targets

target ndash detector distance is 13 m

Energy resolution

2) Measurement of neutron production by spallation reactions to zero angle

Deflection of beam of charged protons and other particles by magnet

Choice only of forward protons produced by neutron collisions (head on collision rarr total neutron energy is transferred

Problems 1) inelastic processes at convertor n + p rarr p + n + π0 n + p rarr p + p + π-

2) production of other particles n + p rarr d + π0 n + p rarr d + γ 3) background of particles produced in other places 4) accuracy of knowledge of np scattering cross- section as function of energy

convertor (liquid hydrogen) ndash 093 gcm2

spectrometer 4 multiwire proportional chambers 2 before and 2 after magnet (determination of momentum)

Proton beam at LAMPF (USA) E = 800 MeV

important materials Al Ti Cu W Pb U

Many further experiments studying production of neutrons at spallation reactions and heavy ion collisions

Similarly also neutron production on heavy targets

3) Measurement of neutron production on thick targets or complicated set-ups

Purpose to obtain data about neutron production and transport for benchmark of simulation codes

Set-up of lead target and uranium blanket

Determination of neutron fluencies and spectra by activation method

Display of set-up by simulation code MCNPX

Example Set-up bdquoEnergy plus Transmutationldquo at JINR Dubna

Accelerator Nuclotron

Activation foils and track detectors

Obtained experimental data

Longitudinal distribution Radial distributionEp = 15 GeV

Measured data number of produced nuclei at activation sample normalized on proton and gram of sample

Example of data spatial distribution of neutron fluencies

Such data can be directly compared with simulations

Position along the target [cm] Radial distance [cm]

Radial direction

0

1

2

3

4

5

6

0 5 10 15

r [cm]

EX

PC

EM

24Na

196Au

194Au

206Bi

58Co6 MeV

8 MeV

11 MeV23 MeV 23 MeV

Comparison of experimental data and simulations by means of MCNPX

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10

Production of neutrons by spallation reactions and collisions of protons and heavy ions

Production of neutrons on uranium Ep = 585 MeV (S Cierjacks Phys Rev 36(1987)1976

Proton beam from cyclotrone at SIN (Switzerland) is used ndash pulse 200 ps

Thin targetsholes (d=4cm) in 20 cm of iron rarrnarrowly collimated neutron beamto angles 30o 90o and 150o

NE213 ndash neutron detectorNE102A ndash veto detector ndash suppression of charged particles

1) Example of measurement of neutron production by spallation reactions on thin targets

target ndash detector distance is 13 m

Energy resolution

2) Measurement of neutron production by spallation reactions to zero angle

Deflection of beam of charged protons and other particles by magnet

Choice only of forward protons produced by neutron collisions (head on collision rarr total neutron energy is transferred

Problems 1) inelastic processes at convertor n + p rarr p + n + π0 n + p rarr p + p + π-

2) production of other particles n + p rarr d + π0 n + p rarr d + γ 3) background of particles produced in other places 4) accuracy of knowledge of np scattering cross- section as function of energy

convertor (liquid hydrogen) ndash 093 gcm2

spectrometer 4 multiwire proportional chambers 2 before and 2 after magnet (determination of momentum)

Proton beam at LAMPF (USA) E = 800 MeV

important materials Al Ti Cu W Pb U

Many further experiments studying production of neutrons at spallation reactions and heavy ion collisions

Similarly also neutron production on heavy targets

3) Measurement of neutron production on thick targets or complicated set-ups

Purpose to obtain data about neutron production and transport for benchmark of simulation codes

Set-up of lead target and uranium blanket

Determination of neutron fluencies and spectra by activation method

Display of set-up by simulation code MCNPX

Example Set-up bdquoEnergy plus Transmutationldquo at JINR Dubna

Accelerator Nuclotron

Activation foils and track detectors

Obtained experimental data

Longitudinal distribution Radial distributionEp = 15 GeV

Measured data number of produced nuclei at activation sample normalized on proton and gram of sample

Example of data spatial distribution of neutron fluencies

Such data can be directly compared with simulations

Position along the target [cm] Radial distance [cm]

Radial direction

0

1

2

3

4

5

6

0 5 10 15

r [cm]

EX

PC

EM

24Na

196Au

194Au

206Bi

58Co6 MeV

8 MeV

11 MeV23 MeV 23 MeV

Comparison of experimental data and simulations by means of MCNPX

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10

2) Measurement of neutron production by spallation reactions to zero angle

Deflection of beam of charged protons and other particles by magnet

Choice only of forward protons produced by neutron collisions (head on collision rarr total neutron energy is transferred

Problems 1) inelastic processes at convertor n + p rarr p + n + π0 n + p rarr p + p + π-

2) production of other particles n + p rarr d + π0 n + p rarr d + γ 3) background of particles produced in other places 4) accuracy of knowledge of np scattering cross- section as function of energy

convertor (liquid hydrogen) ndash 093 gcm2

spectrometer 4 multiwire proportional chambers 2 before and 2 after magnet (determination of momentum)

Proton beam at LAMPF (USA) E = 800 MeV

important materials Al Ti Cu W Pb U

Many further experiments studying production of neutrons at spallation reactions and heavy ion collisions

Similarly also neutron production on heavy targets

3) Measurement of neutron production on thick targets or complicated set-ups

Purpose to obtain data about neutron production and transport for benchmark of simulation codes

Set-up of lead target and uranium blanket

Determination of neutron fluencies and spectra by activation method

Display of set-up by simulation code MCNPX

Example Set-up bdquoEnergy plus Transmutationldquo at JINR Dubna

Accelerator Nuclotron

Activation foils and track detectors

Obtained experimental data

Longitudinal distribution Radial distributionEp = 15 GeV

Measured data number of produced nuclei at activation sample normalized on proton and gram of sample

Example of data spatial distribution of neutron fluencies

Such data can be directly compared with simulations

Position along the target [cm] Radial distance [cm]

Radial direction

0

1

2

3

4

5

6

0 5 10 15

r [cm]

EX

PC

EM

24Na

196Au

194Au

206Bi

58Co6 MeV

8 MeV

11 MeV23 MeV 23 MeV

Comparison of experimental data and simulations by means of MCNPX

• Slide 1
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3) Measurement of neutron production on thick targets or complicated set-ups

Purpose to obtain data about neutron production and transport for benchmark of simulation codes

Set-up of lead target and uranium blanket

Determination of neutron fluencies and spectra by activation method

Display of set-up by simulation code MCNPX

Example Set-up bdquoEnergy plus Transmutationldquo at JINR Dubna

Accelerator Nuclotron

Activation foils and track detectors

Obtained experimental data

Longitudinal distribution Radial distributionEp = 15 GeV

Measured data number of produced nuclei at activation sample normalized on proton and gram of sample

Example of data spatial distribution of neutron fluencies

Such data can be directly compared with simulations

Position along the target [cm] Radial distance [cm]

Radial direction

0

1

2

3

4

5

6

0 5 10 15

r [cm]

EX

PC

EM

24Na

196Au

194Au

206Bi

58Co6 MeV

8 MeV

11 MeV23 MeV 23 MeV

Comparison of experimental data and simulations by means of MCNPX

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10

Obtained experimental data

Longitudinal distribution Radial distributionEp = 15 GeV

Measured data number of produced nuclei at activation sample normalized on proton and gram of sample

Example of data spatial distribution of neutron fluencies

Such data can be directly compared with simulations

Position along the target [cm] Radial distance [cm]

Radial direction

0

1

2

3

4

5

6

0 5 10 15

r [cm]

EX

PC

EM

24Na

196Au

194Au

206Bi

58Co6 MeV

8 MeV

11 MeV23 MeV 23 MeV

Comparison of experimental data and simulations by means of MCNPX

• Slide 1
• Slide 2
• Slide 3
• Slide 4
• Slide 5
• Slide 6
• Slide 7
• Slide 8
• Slide 9
• Slide 10