CEFAS24-87 Contract for multi channel low level gas flow proportional alpha beta counter

Background: Cefas currently have an extensive suite of detection systems that simultaneously measure very low environmental levels of alpha and beta radioactivity in solid sources. These support a number of research and monitoring programmes into the fate of radionuclides in the environment. Cefas require an additional instrument to complement the current suite. Scope of Requirements: Cefas require a multiple chamber detector system for counting 60mm trays, capable of simultaneous detection of low environmental levels of alpha and beta radiation. The background count rate must be stable and <1cpm for beta and <0.1cpm for alpha. Spillover from alpha into beta should be minimal and the system is required to be compatible with standard UK electrical provision (~240V ac at 50/60Hz) and P10 gas (Ar/Meth). The system must have effective shielding, and an internal guard counter to eliminate both cosmic and local sources of radiation. The system is required to have an effective archive where previous sample counts/bgds and calibration runs can be retrieved and quality assessed. Output is to be direct to a local printer option, or ideally transferred to Excel. The system must be compatible with installation into a stable, temperature-controlled environment maintained at 18C.