Extremely high dose neutron dosimetry using CR-39 and atomic force microscopy.

Area of Science:

• Nuclear physics and materials science
• Radiation detection and measurement

Background:

• CR-39 nuclear track detectors are utilized for neutron dosimetry.
• High-dose neutron measurements present challenges for traditional methods.

Purpose of the Study:

• To investigate the feasibility of using Atomic Force Microscopy (AFM) for high-dose neutron dosimetry with CR-39 detectors.
• To establish a method for extracting neutron dose information from etch pit characteristics.

Main Methods:

• Utilized a (239)Pu-Be neutron source for calibration.
• Employed high-density polyethylene (CH(2)) as a recoil proton radiator.
• Measured etch pit densities on CR-39 detectors after short etching times (approx. 1 micrometer).
• Applied AFM for precise measurement of etch pit characteristics and density.

Main Results:

• Measured etch pit densities as a function of neutron fluence up to 1.4 x 10(10) cm(-2) (6.6 Sv).
• Determined a neutron sensitivity of 6.6 x 10(-4).
• Estimated the maximum measurable neutron dose to be approximately 200 Sv based on the fraction of image area occupied by etch pits.

Conclusions:

• AFM is a viable technique for analyzing CR-39 nuclear track detectors in high-dose neutron dosimetry.
• The method allows for accurate neutron dose assessment by measuring etch pit density.
• AFM offers potential for extending the measurable dose range in neutron dosimetry applications.