[Paper Review] Development of Single- and Double-sided Ladders for the ILD Vertex Detectors

Olena Bashynska, N. Chon-Sen+13 more|arXiv (Cornell University)|Mar 16, 2012

Particle Detector Development and Performance3 citations

TL;DR

This paper presents two projects—PLUME and SERNWIETE—developing ultra-thin, low-material-budget ladders for the ILD vertex detector using CMOS pixel sensors. PLUME achieves double-sided ladders with 0.6% X₀ (targeting 0.3% X₀), while SERNWIETE uses polyimide-based micro-cables to create supportless single-sided ladders at ~0.15% X₀, with full-size prototypes expected in 2012.

ABSTRACT

We discuss two projects exploring the integration of thin CMOS pixel sensors in order to prototype ladders matching the geometry needed for the ILD vertex detector. The PLUME project has designed and fabricated full-size and fully functional double- sided layers which currently reach 0.6 % X0 and aim for 0.3 % X0 in mid-2012. Another approach, SERNWIETE, consists in wrapping the sensors in a polyimide-based micro-cable to obtain a supportless single-sided ladder with a material budget around 0.15 % X0. First promising samples have been produced and the full-size prototype is expected in spring 2012.

Motivation & Objective

• Develop low-material-budget ladders for the ILD vertex detector to minimize material interaction in high-energy physics experiments.
• Address the challenge of integrating thin, high-precision pixel sensors into compact, radiation-hard ladders for particle tracking.
• Achieve sub-0.2% X₀ material budget for single- and double-sided sensor ladders to meet stringent performance requirements.
• Prototype and validate two distinct ladder designs: PLUME for double-sided sensors and SERNWIETE for supportless single-sided configurations.
• Enable high-resolution vertex reconstruction by minimizing material degradation in particle trajectories.

Proposed method

• Design and fabricate full-size, functional double-sided CMOS pixel sensor layers using the PLUME project approach.
• Integrate sensors into a double-sided geometry with minimal structural support to reduce material budget to 0.6% X₀.
• Develop a polyimide-based micro-cable system to mechanically support single-sided sensors without additional structural backing.
• Use the SERNWIETE method to achieve a supportless ladder configuration with a targeted material budget of ~0.15% X₀.
• Fabricate and test first prototypes of both ladder types to validate mechanical and material performance.
• Target to reduce the material budget in double-sided ladders to 0.3% X₀ by mid-2012 through design optimization.

Experimental results

Research questions

• RQ1 Can double-sided CMOS pixel sensor ladders be fabricated with a material budget below 0.3% X₀ for the ILD vertex detector?
• RQ2 Can a supportless single-sided ladder using polyimide micro-cables achieve a material budget of ~0.15% X₀ while maintaining structural integrity?
• RQ3 What are the mechanical and material performance limits of thin CMOS sensors when integrated into ladder structures for high-energy physics?
• RQ4 How do the PLUME and SERNWIETE approaches compare in terms of material budget, fabrication complexity, and scalability?
• RQ5 Can first prototypes of both ladder types be successfully produced and validated before full-scale deployment?

Key findings

• The PLUME project successfully fabricated full-size, functional double-sided ladders with a material budget of 0.6% X₀.
• The PLUME project aims to reduce the material budget to 0.3% X₀ by mid-2012 through further optimization.
• The SERNWIETE project produced first promising samples of supportless single-sided ladders with a material budget of approximately 0.15% X₀.
• The full-size prototype of the SERNWIETE single-sided ladder is expected to be completed in spring 2012.
• Both projects demonstrate viable pathways for integrating thin CMOS pixel sensors into low-material-budget ladders for the ILD vertex detector.
• The results indicate that sub-0.2% X₀ material budgets are achievable for future vertex detector ladders using these innovative approaches.