Construction of precision wire readout planes for the Short-Baseline Near Detector (SBND)

Abstract

Baseline Near Detector time projection chamber is unique in the design of its charge readout planes. These anode plane assemblies (APAs) have been fabricated and assembled to meet strict accuracy and precision requirements: wire spacing of 3 mm ± 0.5 mm and wire tension of 7 N ± 1 N across 3,964 wires per APA, and flatness within 0.5 mm over the 4 m × 2.5 m extent of each APA. This paper describes the design, manufacture and assembly of these key detector components, with a focus on the quality assurance at each stage. K: Detector design and construction technologies and materials; Neutrino detectors; Time projection chambers; Noble liquid detectors (scintillation, ionization, double-phase)

Review of Liquid Argon Detector Technologies in the Neutrino Sector

“…In terms of the fundamental design, each of the SBND APAs [36] is identical to that of MicroBooNE: three parallel planes of wires denoted as U, V and Y in order of innermost to outermost, respectively orientated at angles of +60°, −60°and 0°in relation to vertical, and with both wire-to-wire and inter-plane spacings of 3 mm. This is depicted schematically in Figure 15 (left) and photographed in Figure 15 (right).…”

“…This is depicted schematically in Figure 15 (left) and photographed in Figure 15 (right). The planes are biased at −200 V, 0 V and +430 V (U, V and Y respectively) [36], once again resulting in two induction planes and one collection plane. The wires in a single APA are installed in a stainless steel frame that forms a 2 × 3 grid of "windows", and so each of the drift volumes' outer faces therefore consists of two such APAs, as previously shown in Figure 13.…”

“…The APAs on each face are manufactured and wired independently, before being electronically coupled so that they effectively function as a single structure. To ensure flatness of the wires across each APA's full height and width and to support them away from their soldered mounting points on the perimeter of the frames, specially designed combs are installed on the frames' cross-beams [36]. As with the use of a membrane cryostat, the design, manufacturing and testing of the SBND APAs has acted as prototyping for the DUNE experiments, which are expected to use wire planes of similar design and size.…”

Cosmic Ray Background Removal With Deep Neural Networks in SBND

“…The SBND detector is a dual drift TPC, with a central, shared cathode and two anodes, one at each side of the detector (see Figure 1 ). The vertical wire planes each have 1,664 wires (plane 2 in images in this work), and each of the induction planes (angled at ±60°, planes 0 and 1 in this work) have 1,984 wires (Acciarri et al, 2020 ). Each TPC is ~5 m long, 4 m high, and 2 m in the drift direction—for a total width of ~4 m. The entire TPC is located within a cryogenic system, as seen in Figure 2 .…”

Review of Liquid Argon Detector Technologies in the Neutrino Sector

“…In terms of the fundamental design, each of the SBND APAs [36] is identical to that of MicroBooNE: 3 parallel planes of wires denoted as U, V and Y in order of innermost to outermost, respectively orientated at angles of +60°, -60°and 0°in relation to vertical, and with both wire-to-wire and inter-plane spacings of 3 mm. This is depicted schematically in Figure 15 (left) and photographed in Figure 15 (right).…”