Presentation on theme: "PIGE experience in IPPE Institute of Physics and Power Engineering, Obninsk, Russia A.F. Gurbich."— Presentation transcript:
PIGE experience in IPPE Institute of Physics and Power Engineering, Obninsk, Russia A.F. Gurbich
Overview For the analysis of carbon, sodium, aluminum, and chromium resonance PIGE was employed. The excitation functions for the corresponding reactions were measured in the vicinity of resonances favorable for analytical applications. The oxygen analysis using gammas from direct non-resonant radiative capture was undertaken. PIGE was used for the analysis of various samples including semiconductor structures and nuclear reactor materials. Hydrogen analysis using resonance 1 H( 19 F, ) 16 O reaction was used to study hydrogen penetration into coating layers on the surface of zirconium pipes. Propagation of the spectrometer efficiency calibration on the high energy region was made using cascade gamma quanta from the resonance 27 Al(p, ) 28 Si reaction with known gamma ray branching. Tickonov’s regularization method was applied to resolve the ill-posed problem of the determination of concentration on depth distribution. Pulsed incident beam was used to substantially enhance the sensitivity of the PIGE analysis due to suppression of the background gamma-radiation.
Thick target yield for resonance The resonance yield per unity solid angle and unity incident particles charge for prompt gamma-rays emission from homogenous target with energy thickness of E T is defined as where N 0 - is Avogadro constant, A - is a molecular mass, c - is element concentration in the target. Assuming the Breit-Wigner resonance where R - is a cross section at resonance energy E R and - is a resonance width, the yield for an infinitely thick target ( E T >> ) is The R, , and E R may be regarded as free parameters and these have to be found by fit of theoretical yield to measured data.
Thick target yield for the 23 Na(p,p’ ) 23 Na reaction (E =439 keV) in the vicinity of the resonance and its theoretical description − Bodart F., Deconninck G., Demortier G. Quantitative analysis of sodium by (p, )-reactions. J. Radioanal. Chem. 35 (1977) 95 − This measurement (target – NaCl, detector – Ge(Li), proton beam from the EG-2.5 Van de Graaff accelerator of IPPE) Deduced resonance parameters E R =1456 1.8 keV and =8.3 0.8 keV
Thick-target yield of gamma rays from the 27 Al(p, ) 28 Si reaction Resonance energies are indicated by bars
Thick target yield of -rays at the 991.9 keV resonance in the 27 Al(p, ) 28 Si reaction Proton energy, keV − Deconninck G., Demortier G. Quantitative analysis of aluminium by prompt nuclear reactions. J. Radioanal. Chem. 12 (1972)189. − This measurement
PIGE analysis of carbon Intense resonances in the reaction 12 С(p, ) 13 N (Q=1944.01 0.22 keV) are observed at 0.457 and 1.699 MeV. For the Е p = 457 keV resonance (total width Г=35 keV, resonance cross- section =127 mb) the ray energy is 2.366 MeV. For the Е p = 1.699 MeV resonance (total width Г=70 keV, resonance cross- section =35 mb) the -ray energy is 3.51 MeV. Gamma ray energy (b) keV (a)– graphite (b) – steel (~0.1% of carbon concentration)
Excitation function of the 52 Cr(p, ) 53 Mn reaction From R.L.Schulte et al. Nucl. Phys. A243 (1975) 202
Thick target yield of -rays at the 1005 keV resonance in the 52 Cr(p, ) 53 Mn reaction Proton energy, keV The IAR at Е p = 1005 keV decays mainly through the levels at 2.87 MeV (26%) and 3.18 MeV (20%) whereas the contribution of all other resonances in population of these levels is small. Thus measured spectra contain gamma quanta which are specific only for this resonance.
Gamma-ray spectrum (high energy part) for the decay of the IAR at E p= 1005 keV in the 52 Cr(p, ) 53 Mn reaction
Gamma-ray spectrum (low energy part) for the decay of the IAR at E p= 1005 keV in the 52 Cr(p, ) 53 Mn reaction
Oxygen analysis using gammas from direct non-resonant radiative capture Counts/Channel Channel Number
The resonance parameters for the 1 H( 19 F, ) 16 O reaction E R, MeV , keV Peak value 6.41844.11675 9.12117.1669 11.1985752954 12.58380.13867 15.686105.53039 16.44185.469847 17.634152.938201
The gamma ray yield for the 1 H( 19 F, ) 16 O reaction. The EXFOR data for the 19 F(p, ) 16 O reaction were converted for the case when 19 F is a projectile
A typical spectrum of gamma quanta from the 1 H( 19 F, ) 16 O reaction measured with a NaI(Tl) detector at the 19 F 2+ beam energy of 9.2 MeV
The spectrum of gamma rays for the 27 Al(p, ) 28 Si reaction from which the spectrometer efficiency for high energy gamma quanta was determined
Branching for a resonance in the 27 Al(p, ) 28 Si reaction at E p =767 keV 12.323 4.617 MeV 4.617 1.779 MeV Solid line – E =7.706 MeV Dashed line – E =2.873 MeV Angular distribution
Resolving inverse problem using the regularization method The gamma ray yield The derived hydrogen profile In order to derive the concentration on depth distribution c(x) the Fredholm equation of the first kind should be resolved. This ill-posed problem was resolved using Tickonov’s regularization method.
Gamma-ray yield for the aluminized steel sample Dots – experiment Line – theoretical fit Yield, arbitrary units keV 27 Al(p, 28 Si
Characteristics of the reactions used for PIGE analysis of the BN-600 atomic power plant steam generator wall Reaction -ray energy, MeV Resonance energy, MeV Proton beam energy Depth resolution, m Maximal depth, m 12 C(p, o ) 13 N 2.3660.4570.50.24 16 O(p, 1 ) 17 F 16/17E p (x)+0.1050.80.043 23 Na(p, ) 20 Ne 1.6341.0111.011-1.0700.0160.6 23 Na(p,p’ ) 23 Na 0.4401.28313000.07 52 Cr(p, ) 53 Mn 0.3781.0051.005-1.0800.050.8
Sodium distribution near the surface of an oxidized silicon wafer The insert shows a part of gamma-spectrum around the sodium line at E =439 keV for oxidized ( ) and virgin ( ) samples for irradiation with a proton beam of Ep=1470 keV mass % mm
PIGE analysis of a semiconductor laser structure Substrate Sub-layer n-emitter Active layer p-emitter Surface keV ~1 m ~0.2 m 4-5 m mm mm
Aluminum depth profile near surface of the samples tested in the flow of melted lead. Solid line – results obtained using 27 Al(d,p 0+1 ) 28 Al reaction. Dashed line – PIGE results.