Vacature Internship / Stage Next-Generation X-Ray sensors

Varex Imaging Nederland in Doetinchem develops, produces and supplies components for medical and industrial X-ray equipment and has an interesting internship position:

Internship / Stage Next-Generation X-Ray sensors

Objective:
Conduct a feasibility study for a new Automatic Exposure Control (AEC) amplifier front-end compatible with ionization chamber technology in medical X-ray systems. The goal is to analyze technical requirements, explore potential architectures, and deliver a well-supported recommendation for next steps toward implementation.

Background:
The AEC system ensures that an X-ray system delivers the optimal radiation dose for high-quality imaging while minimizing patient exposure. X-ray intensity is measured using an ionization chamber (or optionally solid-state sensors) positioned near the detector. These sensors produce extremely small currents proportional to the dose rate. The AEC amplifier converts these picoamp-level currents into a proportional signal that the X-ray generator uses to terminate exposure precisely.

Current solutions rely on aging components and face challenges such as leakage currents, noise, and compliance with medical standards. A next-generation design must address these issues while remaining cost-effective and reliable.

Scope:

• Define functional and performance requirements (noise, leakage, dynamic range).
• Investigate candidate architectures (e.g., switched-capacitor vs. transimpedance).
• Perform basic simulations or calculations to validate feasibility.
• Build a working proof of concept to demonstrate core functionality.
• Solid-state sensor compatibility: optional, considered only if time permits.
• Deliverables: feasibility report with design recommendations and risk assessment.

Deliverables:

• Requirements specification document.
• Comparative analysis of amplifier architectures.
• Simulation results or analytical validation of selected concept.
• Working proof of concept demonstrating key functionality.
• Final feasibility report with recommendations for prototype development.

Learning goals:

• Master techniques for measuring and conditioning ultra-low currents (picoampere to nanoampere range).
• Apply analog electronics principles under real-world constraints such as leakage and noise.
• Gain experience in concept validation, simulation, and technical reporting.
• Understand compliance considerations for medical electronics (IEC 60601).

Technical challenge:

• Accurate measurement and conditioning of extremely low-level currents.
• Minimizing leakage and noise through circuit design and PCB layout strategies.
• Ensuring stability and reliability in high-impedance environments.

Level:

• Graduating from a Bachelor's degree in Electrical Engineering.
• Student at the Technical University of Electrical Engineering.

Additional information:

• Expected period: February until July 2026..
• We offer a market-based compensation.
• Work will mainly be carried out at the location in Doetinchem.

Varex is located in a new, comfortable, and spacious building, designed for the future and equipped with the latest developments, creating a fantastic working environment. The building is centrally located with excellent access routes and within walking distance of the train and bus station.