Radiation Challenge

As part of the HL-LHC upgrade, piezo valve actuators may be installed in areas exposed to radiation levels exceeding 50 kGy.

The actuators were originally equipped with integrated industrial electronics containing ICs and microcontrollers. These components are susceptible to radiation-induced failures at doses significantly below the expected environmental exposure, making the original electronics unsuitable for operation in highly radiated areas.

To address this limitation, a custom CERN PCB was developed to replace the original electronics while maintaining the actuator functionality. The design was based on a simplified architecture using only relays, resistors, capacitors, and diodes, avoiding the radiation-sensitive integrated components.

Electronics Replacement & Validation

The original valve electronics had to be carefully removed from the actuators before installing the CERN PCB. The replacement electronics were designed to reproduce the required actuator functionality while eliminating the integrated components that limited the radiation tolerance of the original design.

Following the modification, the actuators were tested to verify that the replacement electronics preserved the required operating specifications.

The modified actuators were subsequently used as part of radiation testing to evaluate the behaviour of the complete assembly under high-radiation conditions.

Radiation Effects on Mechanical Components

The radiation environment also affects the mechanical materials surrounding the electronics. In a passive radiation test, a piezo valve actuator was exposed to 56 kGy to evaluate the effects of radiation on its materials.

Following irradiation, the original black holding case became brittle. This demonstrated that radiation tolerance was not limited to the electronic components and that the mechanical parts of the actuator also required consideration.

The holding case was therefore redesigned and 3D printed using Accura25 and ULTEM materials. Further radiation testing was planned to evaluate the long-term performance of the redesigned cases and the complete actuator assembly.