Chiyoda Techunol Corporation


Dosimetry Equipment

Chiyoda Technol Corporation launched Japan’s first personal radiation monitoring service in 1954 by film badge and switched to radiophotoluminescence dosimeters (RPLDs) in 2000. Based on our extensive experience and achievements in dosimetry in Japan, we sell and distribute various dosimetry systems abroad today.

Clinical Dosimetry

Clinical Dosimetry System

Radiotherapy is highly effective in cancer treatment. It preserves patients’ physical functions, unlike surgery, so the burden of treatment on patients is small and it can increase their quality of life. However, overly high doses adversely affect healthy tissues, while insufficient doses do not produce adequate therapeutic effects. To ensure quality radiation therapy, radiologists and medical physicists must know exactly how many doses should be delivered. DoseAce, a small clinical dosimetry system using RPLDs, accurately measures the clinical radiation dose.

Monitoring System

Environmental Monitoring System

In Japan, the Nuclear Regulation Authority (NRA) requires radiation monitoring in the environment near nuclear facilities such as nuclear power plants, fuel processing and reprocessing facilities. Our environmental monitoring system can measure the cumulative dose at such facilities, and this data is used to estimate the ambient dose. Methods of measuring environmental radioactivity with RPLDs have been established by the Ministry of Education, Culture, Sports, Science and Technology in Japan, where RPLDs are used in many facilities.

Personal Monitoring System

Personal Monitoring System

The RPLDs we use for personal radiation monitoring service in Japan gained widespread acclaim, leading to joint development of a personal monitoring system with IRSN in France in 2006 that achieved world-class measurement performance. This system has been used for many years by IRSN in France.

Neutron Dosimetry

Neutron Dosimetry

Monitoring neutrons in unknown energy spectrums was previously a challenge because low-energy thermal neutrons and high-energy fast neutrons behave differently. But the Wide-range NeuPit System (WNP) developed by Chiyoda Technol can swiftly measure the neutrons in wide-range energy from thermal to fast neutrons.

Having problems with your current Neutron Detector?

Neutron Dosimetry

Is your current neutron detector noisy? Does it lack sensitivity? Our TechnoTrak 2 neutron track detectors significantly lower surface noise while delivering consistently high sensitivity. Elements are available in various sizes to meet your needs.

RPLD – Radiophotoluminescence Dosimeter


Neutron Dosimetry

The detectors of RPLDs are made of silver-activated phosphate glass containing silver ions. These ions capture the electrons and holes generated by ionizing radiation and create luminescent centers that remain highly stable for years against room temperature and visible photoluminescence. Being excited by ultraviolet laser, the centers produce fluorescence proportional to the dose. This phenomenon is called radiophotoluminescence. The readouts can be repeated by stimulation of ultraviolet laser to ensure high accuracy. Only high temperature treatment resets the state of luminescent centers, namely dose information, and the glass detector can be used again*.

If the glass becomes tinted when exposed to high doses, it should be replaced.


RPLDs can be handled at room temperature under fluorescent lamps since they are not affected by room temperature or light. Just supply them with power: no darkroom or cooling gas is required.

Glass detectors offer excellent uniformity and do not require individual detector sensitivity correction*
Dose readings can be repeated multiple times
Dose readings are highly reproducible
Fading is negligible and reliability (integrity) is high

Reader calibration is required for energy correction because it is not tissue equivalent.