Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

The H1 Silicon Vertex Detector

D. Pitzl

TL;DR

The H1 CST demonstrates a two-layer silicon vertex detector with DC-coupled double-sided sensors and a custom APC128 readout designed for rapid, low-material tracking near the interaction point. Through a sophisticated optical readout, on-line processing, and a comprehensive three-tier alignment program (optical survey, internal, and global), the CST achieves high hit efficiency and excellent impact-parameter resolution, enabling heavy-quark tagging in ep collisions. The system integrates radiation and temperature monitoring to maintain performance under collider conditions, with beam-line reconstruction leveraging CST data for precise beam-position measurements. Overall, the CST provides precise vertexing and robust offline reconstruction capabilities that enhance heavy-flavor physics in H1 at HERA.

Abstract

The design, construction and performance of the H1 silicon vertex detector is described. It consists of two cylindrical layers of double sided, double metal silicon sensors read out by a custom designed analog pipeline chip. The analog signals are transmitted by optical fibers to a custom designed ADC board and are reduced on PowerPC processors. Details of the design and construction are given and performance figures from the first data taking periods are presented.

The H1 Silicon Vertex Detector

TL;DR

The H1 CST demonstrates a two-layer silicon vertex detector with DC-coupled double-sided sensors and a custom APC128 readout designed for rapid, low-material tracking near the interaction point. Through a sophisticated optical readout, on-line processing, and a comprehensive three-tier alignment program (optical survey, internal, and global), the CST achieves high hit efficiency and excellent impact-parameter resolution, enabling heavy-quark tagging in ep collisions. The system integrates radiation and temperature monitoring to maintain performance under collider conditions, with beam-line reconstruction leveraging CST data for precise beam-position measurements. Overall, the CST provides precise vertexing and robust offline reconstruction capabilities that enhance heavy-flavor physics in H1 at HERA.

Abstract

The design, construction and performance of the H1 silicon vertex detector is described. It consists of two cylindrical layers of double sided, double metal silicon sensors read out by a custom designed analog pipeline chip. The analog signals are transmitted by optical fibers to a custom designed ADC board and are reduced on PowerPC processors. Details of the design and construction are given and performance figures from the first data taking periods are presented.

Paper Structure

This paper contains 35 sections, 3 equations, 19 figures.

Table of Contents

  1. Introduction
  2. Layout
  3. Geometry
  4. Mechanical Frame and Installation
  5. Frontend Components
  6. Silicon Sensors
  7. Analog Pipeline Chip
  8. Preamplifier
  9. Pipeline
  10. Re-read and offset subtraction
  11. Serial readout
  12. Decoder Chip
  13. Hybrid and Optical Readout
  14. Readout and Monitoring
  15. Readout and on-line Data Processing
  16. ...and 20 more sections

Figures (19)

  • Figure 1: CST geometry in the r-$\phi$-plane.
  • Figure 2: Side view of the upper half of the CST.
  • Figure 3: Carbon-fiber endflange. The cover is removed to display the integrated cooling pipe. Copper-tin sheets provide thermal contact to each balcony where the hybrids are mounted.
  • Figure 4: View of the lower half of the CST and the service tube which surrounds the BST and contains the supply cables, the optical fibers and pipes for cooling water. Both are supported by the carbon fiber support tube which contains a carbon fiber sliding rail for insertion. The beam pipe is not shown.
  • Figure 5: Schematic view of a half ladder. The upper part shows the p-side, the lower part the n-side.
  • ...and 14 more figures