Environmental measurement group

The group contributes to the development of accelerator science based on analytical chemistry techniques

Purpose and Vision

For fundamental technology for stable operation and development of the accelerators, the groupe is engaged in research from a point of view of analytical chemistry. In addition, we are conducting research and development of chemical safety in KEK and the environmental management.


By radiation generated during the operation of the accelerators, colloid particles and/or colloidal ions are generated in cooling water, harmful gases and/or aerosol are generated in air. These colloidal particles are often radioactive themselves and can be carriers of radioactive elements. Therefore, it is important to analyze and understand the chemical behavior of these colloidal particles, in order to operate the accelerator facilities safely.

We have analyzed aerosol particles in air and elucidated the formation mechanism of aerosol by radiation. Now, we are examining the generation mechanism and the state of existence of cilloid particels in cooling waters of various accelerator facilities. In addition, we are studying the effect of radiation on corrosion of metal material in cooling water, and uptake mechanism of radionuclides to colloid particles.

For the surface treatment of the superconducting radiofrequency (rf) cavity, we are cooperating in the research and development from a point of view of chemistry. In order to get the cavity performance, polishing and cleaning of inner surface of the niobium cavity using chemical and electrochemical procedure is required. Especially, electrolytic polishing using a mixed solution of hydrofluoric and sulfuric acid is the key procedure. For the establishment of optimal polishing conditions, we have investigated the composition of the electrolyte solution by using various spectroscopic techniques and chemical analysis. Also, we are conducting research on and analysis of the reaction mechanism of electrolytic polishing.

Related to the management of chemical and environmental safety, we are carrying out the analysis of trace chemical species in the environment, the study on the treatment technique of various types of waste liquid that discharged from the research activities, and the study of the mechanism of groundwater. In addition to those studies, we are conducting chemical analysis of various samples that are requested by other research groups and technological development associated with it.