35 research outputs found
Neutrino Oscillations for Dummies
The reality of neutrino oscillations has not really sunk in yet. The
phenomenon presents us with purely quantum mechanical effects over macroscopic
time and distance scales (milliseconds and 1000s of km). In order to help with
the pedagogical difficulties this poses, I attempt here to present the physics
in words and pictures rather than math. No disrespect is implied by the title;
I am merely borrowing a term used by a popular series of self-help books
OpenPodcar: An Open Source Vehicle for Self-Driving Car Research
OpenPodcar is a low-cost, open source hardware and software, autonomous vehicle research platform based on an off-the-shelf, hard-canopy, mobility scooter donor vehicle. Hardware and software build instructions are provided to convert the donor vehicle into a low-cost and fully autonomous platform. The open platform consists of (a) hardware components: CAD designs, bill of materials, and build instructions; (b) Arduino, ROS and Gazebo control and simulation software files which provide standard ROS interfaces and simulation of the vehicle; and (c) higher-level ROS software implementations and configurations of standard robot autonomous planning and control, including the move\_base interface with Timed-Elastic-Band planner which enacts commands to drive the vehicle from a current to a desired pose around obstacles. The vehicle is large enough to transport a human passenger or similar load at speeds up to 15km/h, for example for use as a last-mile autonomous taxi service or to transport delivery containers similarly around a city center. It is small and safe enough to be parked in a standard research lab and be used for realistic human-vehicle interaction studies. System build cost from new components is around USD7,000 in total in 2022. OpenPodcar thus provides a good balance between real world utility, safety, cost and research convenience
Muon-Induced Background Study for Underground Laboratories
We provide a comprehensive study of the cosmic-ray muon flux and induced
activity as a function of overburden along with a convenient parameterization
of the salient fluxes and differential distributions for a suite of underground
laboratories ranging in depth from 1 to 8 km.w.e.. Particular attention
is given to the muon-induced fast neutron activity for the underground sites
and we develop a Depth-Sensitivity-Relation to characterize the effect of such
background in experiments searching for WIMP dark matter and neutrinoless
double beta decay.Comment: 18 pages, 28 figure
Assembly, apparatus, system and method (PRaVDA range telescope)
Some embodiments of the present invention provide apparatus for detecting particles of radiation comprising: a plurality of solid state semiconductor detector devices provided at spaced apart locations along a beam axis, the detector devices each being configured to generate an electrical signal indicative of passage of a particle through or absorption of a particle by the device; and at least one absorber portion configured to absorb at least a portion of an energy of a particle, wherein one said at least one absorber portion is provided in a particle path between at least one pair of adjacent detector devices, the apparatus being configured to provide an output signal indicative of the energy of a particle, the output signal provided being dependent on the electrical signals indicative of passage of a particle through or absorption of a particle by the devices
PRaVDA: The First Solid-State System for Proton Computed Tomography
Proton CT is widely recognised as a beneficial alternative to con- ventional X-ray CT for treatment planning in proton beam radiotherapy. A novel proton CT imaging system, based entirely on solid-state detec- tor technology, is presented. Compared to conventional scintillator-based calorimeters, positional sensitive detectors allow for multiple protons to be tracked per read out cycle, leading to a potential reduction in proton CT scan time. Design and characterisation of its components are discussed. An early proton CT image obtained with a fully solid-state imaging sys- tem is shown and accuracy (as defined in Section IV) in Relative Stopping Power to water (RSP) quantified.
A solid-state imaging system for proton CT, based on silicon strip detectors, has been developed by the PRaVDA collaboration. The sys- tem comprises a tracking system that infers individual proton trajecto- ries through an imaging phantom, and a Range Telescope (RT) which records the corresponding residual energy (range) for each proton. A back-projection-then-filtering algorithm is used for CT reconstruction of an experimentally acquired proton CT scan.
An initial experimental result for proton CT imaging with a fully solid-state system is shown for an imaging phantom, namely a 75 mm diameter PMMA sphere containing tissue substitute inserts,imaged with a passively-scattered 125 MeV beam. Accuracy in RSP is measured to be ≤1.6% for all the inserts shown.
A fully solid-state imaging system for proton CT has been shown capable of imaging a phantom with protons and successfully improving RSP accuracy. These promising results, together with system the capabil- ity to cope with high proton fluences (2×108 protons/s), suggests that this research platform could improve current standards in treatment planning for proton beam radiotherapy
Assembly, apparatus, system and method (PRaVDA strip detector)
Some embodiments of the present invention provide a 2D position-sensitive detector assembly comprising at least three substantially planar detector portions arranged in overlapping relationship as viewed normal to a plane of the detector portions, each detector portion comprising an array of substantially parallel, linear detector elements, the detector elements of respective detector portions being mutually non-parallel, the detector elements each being configured to generate one or more electrical signals in response to interaction of a particle of radiation therewith
UN Decade on Ecosystem Restoration 2021–2030: what chance for success in restoring coastal ecosystems?
On 1 March 2019, the United Nations (UN) General Assembly (New York) declared 2021–2030 the “UN Decade on Ecosystem Restoration.” This call to action has the purpose of recognizing the need to massively accelerate global restoration of degraded ecosystems, to fight the climate heating crisis, enhance food security, provide clean water and protect biodiversity on the planet. The scale of restoration will be key; for example, the Bonn Challenge has the goal to restore 350 million km2 (almost the size of India) of degraded terrestrial ecosystems by 2030. However, international support for restoration of “blue” coastal ecosystems, which provide an impressive array of benefits to people, has lagged. Only the Global Mangrove Alliance (https://mangrovealliance.org/) comes close to the Bonn Challenge, with the aim of increasing the global area of mangroves by 20% by 2030. However, mangrove scientists have reservations about this target, voicing concerns that it is unrealistic and may prompt inappropriate practices in attempting to reach this target (Lee et al., 2019). The decade of ecosystem restoration declaration also coincides with the UN Decade of Ocean Science for Sustainable Development, which aims to reverse deterioration in ocean health. If executed in a holistic and coordinated manner, signatory nations could stand to deliver on both these UN calls to action