Neutron field measurements at the Aladdin Synchrotron Light Source

Area of Science:

• Nuclear physics
• Particle accelerator physics

Background:

• Electron storage rings generate high-energy particle beams.
• Injection processes can lead to the production of secondary radiation, such as neutrons.
• Understanding neutron fields is crucial for radiation safety in accelerator facilities.

Purpose of the Study:

• To characterize the neutron field near the inflector of an 800-MeV electron storage ring.
• To quantify neutron production from photon-induced reactions during electron injection.
• To measure dose equivalent rates and neutron attenuation.

Main Methods:

• Utilized moderating detectors with Lucite blocks and gold (Au) activation foils to measure neutrons.
• Calibrated detector response using a Plutonium-Beryllium (Pu-Be) neutron source and a polyethylene sphere.
• Measured dose equivalent rates at specified distances and above the inflector.

Main Results:

• Determined a neutron yield of 0.97 +/- 0.14 x 10^12 neutrons per kilojoule (kJ^-1).
• Measured dose equivalent rates of 4.35 +/- 0.47 microSieverts per second (µSv s^-1) at 1 m aside and 3.13 +/- 0.23 µSv s^-1 at 1 m above the inflector for 1.38 W electron pulse power.
• Obtained an attenuation coefficient of 15.7 m^-1 for polyethylene.

Conclusions:

• Photon-induced neutrons are produced during electron injection into the storage ring.
• The study provides essential data for radiation shielding and safety assessments.
• Neutron attenuation characteristics in polyethylene are quantified for potential shielding applications.