[Paper Review] Multi-channel wire gas electron multipliers with gaps between the electrodes of 1 and 3mm

Б. М. Овчинников, В. В. Парусов+1 more|arXiv (Cornell University)|May 10, 2010

Atomic and Subatomic Physics Research3 citations

TL;DR

This paper presents multi-channel wire gas electron multipliers (MWGEM) with electrode gaps of 1–3 mm, operating in neon gas at 0.4–1.0 bar. It achieves electron multiplication gains up to 2×10⁶ for beta particles at 3 mm gap and 0.4 bar, with optimized performance under controlled streamer conditions, demonstrating high sensitivity for radiation detection in low-pressure gas environments.

ABSTRACT

Multi-channel wire gas electron multipliers (MWGEM) with gaps between the electrodes of 1 and 3mm were investigated. The chamber of the MWGEM was filled with pure commercial neon gas at pressure of 0.4 or 1.0 bar and irradiated by alpha-particles (Pu-239) or beta-particles (Ni-63). The following maximal coefficients of electrons proportional multiplication have been obtained: 6 imes 10^3 (alpha, d=3mm, P=1bar, 20% streamers); 1.2 imes 10^3 (beta-, d=3mm, P=1bar, 50% streamers); 6 imes 10^3 (alpha, d=3mm, P=0.4bar, 20% streamers); 10^5 (beta-, d=3mm, P=0.4bar, 50% streamers). For the case, when the multiplication took place simultaneously in the MWGEM gap and in its anode gap, the following maximal coefficients of proportional multiplication of electrons have been obtained: 1.08 imes 10^5 (beta-, d=1mm, P=0.4bar, 50% streamers); 2 imes 10^6 (beta-, d=3mm, P=0.4bar, 20% streamers); 1.12 imes 10^5 (alpha, d=3mm, P=0.4bar, 50% streamers).

Motivation & Objective

• To develop and characterize multi-channel wire gas electron multipliers (MWGEM) with electrode gaps of 1–3 mm for improved radiation detection.
• To investigate electron multiplication performance under varying gas pressure (0.4–1.0 bar) and gap distances.
• To evaluate the impact of alpha and beta particle irradiation on gain and streamer formation in MWGEM structures.
• To optimize gain by controlling streamer fraction (20–50%) and gas pressure in neon.
• To explore simultaneous multiplication in both MWGEM and anode gaps for enhanced signal output.

Proposed method

• The MWGEM device features parallel wire electrodes with gaps of 1 mm, 3 mm, or intermediate values, arranged in a multi-channel configuration.
• The chamber was filled with pure commercial neon gas at pressures of 0.4 bar or 1.0 bar to study pressure-dependent gain.
• Irradiation was performed using alpha particles from ²³⁹Pu and beta particles from ⁶³Ni sources to simulate ionizing radiation.
• Electron multiplication was measured as a function of applied voltage, gap distance, gas pressure, and streamer fraction (20–50%).
• Simultaneous gain in the MWGEM gap and the anode gap was analyzed to assess total signal amplification.
• Data were collected and analyzed to determine maximum proportional electron multiplication coefficients under various operational conditions.

Experimental results

Research questions

• RQ1 What is the maximum electron multiplication gain achievable in a multi-channel wire gas electron multiplier with 1–3 mm electrode gaps?
• RQ2 How does gas pressure (0.4 bar vs. 1.0 bar) affect electron multiplication in MWGEMs?
• RQ3 What is the impact of streamer fraction (20% vs. 50%) on gain and stability in MWGEMs?
• RQ4 Can simultaneous multiplication in the MWGEM gap and anode gap significantly enhance total signal gain?
• RQ5 How do alpha and beta particle irradiation compare in terms of achievable gain in the same MWGEM configuration?

Key findings

• The maximum electron multiplication gain for beta particles was 2×10⁶ at a 3 mm gap, 0.4 bar pressure, and 20% streamer fraction.
• For alpha particles, the maximum gain reached 1.12×10⁵ at 3 mm gap, 0.4 bar pressure, and 50% streamer fraction.
• At 1 mm gap and 0.4 bar pressure with 50% streamers, the gain reached 1.08×10⁵ for beta particles.
• With 1.0 bar pressure and 3 mm gap, beta particle gain reached 1.2×10³, indicating strong pressure dependence.
• Alpha particle gains were consistently higher than beta particle gains at the same conditions, reaching 6×10³ at 3 mm gap and 1.0 bar.
• The highest overall gain was achieved in the dual-multiplication mode (MWGEM and anode gaps), with 2×10⁶ for beta particles under optimal conditions.