[Paper Review] ZEPLIN IV: A One Ton Ultimate WIMP Detector

D. Cline|arXiv (Cornell University)|Nov 5, 2001

Dark Matter and Cosmic Phenomena3 citations

TL;DR

This paper proposes ZEPLIN IV, a one-ton liquid xenon time projection chamber designed to detect Weakly Interacting Massive Particles (WIMPs) as predicted by supersymmetry. Building on the ZEPLIN II prototype, it leverages dual-phase xenon scintillation and ionization signals to achieve high sensitivity, positioning a ton-scale detector as essential for observing SUSY WIMPs in upcoming direct detection experiments.

ABSTRACT

We describe the research and development program carried out by the UCLA - Torino group leading to the ZEPLIN II detector under construction for the Boulby Laboratory. Knowledge of ZEPLIN II performance will help in the design and construction of ZEPLIN IV. This detector could be located at a U.S. underground laboratory (WIPP site or others) or elsewhere. We show that a detector of this size is required to observe SUSY WIMPS.

Motivation & Objective

• To design a one-ton liquid xenon time projection chamber capable of detecting supersymmetric WIMPs.
• To establish the necessity of a ton-scale detector for achieving sufficient sensitivity to observe WIMP signals.
• To guide the construction of ZEPLIN IV based on performance data from the ZEPLIN II prototype.
• To evaluate the feasibility of deploying ZEPLIN IV at U.S. underground laboratories such as WIPP.
• To demonstrate that large-scale xenon detectors are essential for probing the full parameter space of SUSY WIMP models.

Proposed method

• Utilize dual-phase liquid xenon time projection chamber technology to detect both scintillation and ionization signals from WIMP interactions.
• Leverage the ZEPLIN II detector's performance data as a foundation for scaling to one ton.
• Apply background rejection techniques using pulse shape discrimination to suppress electron recoil backgrounds.
• Optimize detector geometry and shielding to minimize cosmic ray and radioactive backgrounds.
• Simulate signal-to-background ratios to determine required detector mass for WIMP detection.
• Design for operation in deep underground laboratories to reduce external radiation interference.

Experimental results

Research questions

• RQ1 What detector mass is required to achieve sufficient sensitivity to observe SUSY WIMPs in direct detection experiments?
• RQ2 How does the performance of the ZEPLIN II prototype inform the design of a one-ton detector like ZEPLIN IV?
• RQ3 Can a one-ton liquid xenon TPC achieve the necessary background suppression for WIMP detection?
• RQ4 Where is the optimal location for deploying a one-ton WIMP detector in the U.S.?
• RQ5 What are the key technical and design challenges in scaling from ZEPLIN II to ZEPLIN IV?

Key findings

• A one-ton liquid xenon detector is necessary to achieve the required sensitivity for observing SUSY WIMPs.
• The ZEPLIN II prototype provides critical performance data essential for designing ZEPLIN IV.
• Dual-phase xenon technology enables effective discrimination between WIMP signals and background events.
• Background suppression via pulse shape analysis is feasible at the one-ton scale.
• The WIPP site and other U.S. underground laboratories are viable locations for ZEPLIN IV deployment.
• Scaling to one ton significantly improves the signal-to-background ratio, making WIMP detection achievable.