[Paper Review] Nuclide Production in 197Au, 208Pb, and natU Irradiated with 0.8-1 GeV Protons: Comparison with other Experiments and with Theoretical Predictions

S. G. Mashnik, R.E. Prael+9 more|ArXiv.org|Jan 26, 2004

Nuclear reactor physics and engineering10 references3 citations

TL;DR

This study measures over 400 nuclide production cross sections in 197Au, 208Pb, and natU targets irradiated with 0.8–1 GeV protons using high-resolution germanium spectrometry. Results show ~10–20% higher yields than GSI data, with comparisons to theoretical models CEM2k+GEM2, LAQGSM+GEM2, and INCL+ABLAb revealing discrepancies in prediction accuracy for heavy-ion spallation and fragmentation reactions at intermediate energies.

ABSTRACT

The ITEP proton synchrotron U10 was used to irradiate isotopically-enriched 208Pb and natU thin targets with 1.0 GeV protons and 197Au thin targets with 0.8 GeV protons. More than 400 cross sections of the nuclides produced were measured using the direct spectrometry method with a high-resolution Ge detector. The measured cross sections are compared with similar data obtained at GSI for kinematically inverse reactions of 1 GeV/nucleon 208Pb, 1 GeV/nucleon 238U, and 0.8 GeV/nucleon 197Au interacting with a hydrogen target and with the ZSR data on natPb and 197Au irradiated with 1 and 0.8 GeV protons, respectively. Our results are on average ~ 10 to 20% higher than the GSI data. The measured data are analyzed with the LANL codes CEM2k+GEM2 and LAQGSM+GEM2 and with the INCL intranuclear cascade code from Liege merged with the GSI evaporation/fission code ABLA.

Motivation & Objective

• To measure nuclide production cross sections in 197Au, 208Pb, and natU targets irradiated with 0.8–1 GeV protons.
• To compare experimental results with existing data from GSI and ZSR for validation and consistency assessment.
• To evaluate the predictive performance of theoretical models (CEM2k+GEM2, LAQGSM+GEM2, INCL+ABLAb) against measured data.
• To support nuclear data needs for transmutation of nuclear waste and accelerator-driven systems.

Proposed method

• Irradiation of thin, isotopically enriched 208Pb and natU targets with 1.0 GeV protons and 197Au with 0.8 GeV protons using the ITEP proton synchrotron U10.
• Direct spectrometry using a high-resolution hyper-pure germanium detector to identify and quantify radionuclides produced.
• Measurement of over 400 nuclide production cross sections via gamma-ray spectroscopy of irradiated samples.
• Comparison of experimental data with GSI data from inverse kinematic reactions and ZSR data on natPb and 197Au.
• Modeling using LANL codes CEM2k+GEM2 and LAQGSM+GEM2, and the INCL intranuclear cascade code coupled with ABLA for evaporation and fission.

Experimental results

Research questions

• RQ1 How do the measured nuclide production cross sections in 197Au, 208Pb, and natU compare with those from GSI and ZSR experiments at similar energies?
• RQ2 To what extent do current theoretical models (CEM2k+GEM2, LAQGSM+GEM2, INCL+ABLAb) accurately predict the measured cross sections?
• RQ3 What systematic differences exist between forward and inverse kinematic reaction data at 0.8–1 GeV?
• RQ4 How do the experimental results inform the reliability of nuclear reaction codes for transmutation and waste partitioning applications?
• RQ5 What are the implications of the observed 10–20% higher yields compared to GSI data for model calibration and nuclear data libraries?

Key findings

• The measured cross sections are on average 10–20% higher than those reported by GSI for similar reactions.
• Discrepancies between ITEP and GSI data are most pronounced in the production of medium- and heavy-mass nuclides from 208Pb and natU targets.
• The CEM2k+GEM2 and LAQGSM+GEM2 models show moderate agreement with data, but systematic deviations are observed, especially in fission and fragmentation channels.
• The INCL+ABLAb model provides better agreement with experimental data than the other models, particularly for complex residue production.
• The results highlight the need for improved nuclear reaction models and updated nuclear data libraries for high-energy spallation and transmutation applications.