arXiv subjects

Jane Gunnell

Publications and source records attributed to Jane Gunnell.

3 recordsLinked to original sources

arXiv2026

Barium Magnesium Alloy as Source of Atomic Ba for Ion Trapping

Trapped atomic ion qubits exhibit long coherence times and high fidelity qubit state preparation, manipulation and detection, making them well-suited for scalable quantum computing applications. Among several atomic species used in quantum computing and other application, singly-charged ions of barium stand out due to their long wavelength transitions and the presence of very long-lived metastable internal states. However, elemental barium is a highly reactive metal making it experimentally difficult to work with when making atomic beam sources. In this paper, we demonstrate a method of using resistively heated ovens loaded with a barium magnesium alloy (BaMg) as a source of barium for ion traps. This alloy is not very chemically reactive and does not oxidize in air. We found that a sample of BaMg in a resistively heated oven produced barium vapor pressures on the same order as a metallic barium sample prepared the same way. Two separate ovens, one with a sample of BaMg and one with metallic barium, were used as source for an ion trap. We observed reliable trapping of 138Ba+ ions both with the elemental barium source, and the BaMg source.

physics.atom-ph↗

arXiv2020

The ABC130 barrel module prototyping programme for the ATLAS strip tracker

For the Phase-II Upgrade of the ATLAS Detector, its Inner Detector, consisting of silicon pixel, silicon strip and transition radiation sub-detectors, will be replaced with an all new 100 % silicon tracker, composed of a pixel tracker at inner radii and a strip tracker at outer radii. The future ATLAS strip tracker will include 11,000 silicon sensor modules in the central region (barrel) and 7,000 modules in the forward region (end-caps), which are foreseen to be constructed over a period of 3.5 years. The construction of each module consists of a series of assembly and quality control steps, which were engineered to be identical for all production sites. In order to develop the tooling and procedures for assembly and testing of these modules, two series of major prototyping programs were conducted: an early program using readout chips designed using a 250 nm fabrication process (ABCN-25) and a subsequent program using a follow-up chip set made using 130 nm processing (ABC130 and HCC130 chips). This second generation of readout chips was used for an extensive prototyping program that produced around 100 barrel-type modules and contributed significantly to the development of the final module layout. This paper gives an overview of the components used in ABC130 barrel modules, their assembly procedure and findings resulting from their tests.

physics.ins-det↗

arXiv2017

Updated Results of a Solid-State Sensor Irradiation Study for ILC Extreme Forward Calorimetry

Detectors proposed for the International Linear Collider (ILC) incorporate a tungsten sampling calorimeter (`BeamCal') intended to reconstruct showers of electrons, positrons and photons that emerge from the interaction point of the collider with angles between 5 and 50 milliradians. For the innermost radius of this calorimeter, radiation doses at shower max are expected to reach 100 Mrad per year, primarily due to minimum-ionizing electrons and positrons that arise in the induced electromagnetic showers of e$^+$e$^-$ `beamstrahlung' pairs produced in the ILC beam-beam interaction. However, radiation damage to calorimeter sensors may be dominated by hadrons induced by nuclear interactions of shower photons, which are much more likely to contribute to the non-ionizing energy loss that has been observed to damage sensors exposed to hadronic radiation. We report here on prior highlights and recent results of SLAC Experiment T-506, for which several different types of semiconductor sensors were exposed to doses of radiation induced by showering electrons of energy 3.5-13.3 GeV. By embedding the sensor under irradiation within a tungsten radiator, the exposure incorporated hadronic species that would potentially contribute to the degradation of a sensor mounted in a precision sampling calorimeter. Depending on sensor technology, significant post-irradiation charge collection was observed for doses of several hundred Mrad.

physics.ins-det↗