Center for Exotic Nuclear Studies

STARK (Silicon Telescope Array for Reaction studies in inverse Kinematics)

1. Motivation

• One of the powerful experimental method to study nuclear reactions
• An ejectile reflects the properties of residual nucleus
• Measure energy, angular momentum, cross-section, spectroscopic factor

         Schematic overview of the transfer reaction

         Silicon telescope array for reaction studies in the world

2. Detector design

         STARK conceptual design

         STARK design with a cryogenic gas cell chamber

• Charged particle detection from collision (E,p)
• Barrel type array, 12 + 16 + 12 sided ring
• Φ = 92.5, 118.8, 107 mm, 28.4 mm gap for target
• Δθlab < 1˚ expected with wide coverage (43˚ ~ 78˚, 105˚ ~ 150˚) => Comparable or better than state-of-the-art detectors
• Newly designed resistive silicon strip detector, X6
• Useful for many rare isotope facilities (ex. RIKEN, FRIB and RAON)

3. Detector specification

• Junction side : 8 resistive strips, 5.6 mm pitch (2 read-outs)
• Ohmic side : 4 normal strips
• Active area : 75 × 40.3 mm² (1 mm thickness)
• Position : (Q_H – Q_L) / (Q_H + Q_L) ~ 1 mm resolution expected
• Energy : (Q_H + Q_L)

4. Detector performance test

         Depletion voltage test

         Resolution test

5. Current status & future plan

• X6 detector is arrived and testing the performance
• Assembly structure was delivered
• Preparing electronics for DAQ system
• Detector and DAQ test on 2022
• System commissioning on 2023

         Geant4 simulation

         STARK assembly

         Future plan