Fragmentation cross sections of 165 A MeV 132Xe on Lead Target
Reporter: Miao-Miao Xue
Supervisors: Dong-Hai Zhang and Jun-Sheng Li
Date: August 23, 2026
Charge-changing cross sections are crucial for nuclear structure, cosmic ray propagation, and heavy-ion therapy.
Motivation
Existing data for 132Xe+Pb system are limited.
No direct measurement exists at~165 A MeV, leaving a critical gap for model validation in the intermediate-energy region.
We measured the total and partial charge-changing cross sections at 165 A MeV using CR-39 detectors.
Pb target
Procedure
Projectile fragment
Unreacted beam
Projectile fragment
CR-39 solid-state nuclear track detector
¹³²Xe beam, initial energy 290 A MeV
Step 1
Step 2
Step 3
Step 4
Irradiation
Beam perpendicularly irradiated through CR-39 stacks and Pb targets
Chemical etching
70°C, 6 mol/L NaOH, 30 h
Scanning
HSP-1000 high-speed microscope, both surfaces
Analysis
Pit-Fit software for automatic fitting+ manual verification; track matching between upstream and downstream detectors
Procedure
Chemical etching
Procedure
vBt
Etched surface
Ion trajectory
Damaged region
Chemical etching
Initial surface
vTt
Scanning(HSP-1000 high-speed microscope)
Analysis
Procedure
Peak fitting: Multi-peak Gaussian fitting resolves continuous fragment distributions into individual charge states.
Track etch area distribution of fragments from 165 A MeV ¹³²Xe + Pb fragmentation
Charge Calibration
CR-39 track etch area increases approximately linearly with the incident particle's charge number Z.
Track etch area as a function of charge number Z for 165 A MeV ¹³²Xe + Pb fragments.
Calibration curve
Formula
Bradt-Peters Formula
Result
Total Charge-Changing Cross Section
Result
Preliminary experimental results
Total Charge-Changing Cross Section
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Formula
Measurements
Partial Charge-Changing Cross Sections
PRELIMINARY DATA
Preliminary experimental results
Partial Charge-Changing Cross Sections
Comparison of partial charge-changing cross sections with EPAX3 and FRACS predictions for 165 A MeV ¹³²Xe + Pb
PRELIMINARY DATA
of charge-changing cross sections at ~165 A MeV for ¹³²Xe + Pb
First direct measurement
Total charge-changing cross section
Benchmark for model improvement
Fill the energy gap
Conclusion
THANKS