The Effects of Preheating of a Fine Tungsten Wire and the Polarity of a High-Voltage Electrode on the Energy Characteristics of an Electrically Exploded Wire in Vacuum

Results obtained from experimental and numerical studies of tungsten wires electrical explosion in vacuum are presented. The experiments were performed both with and without preheating of the wires, using positive or negative polarity of a high-voltage electrode. Preheating is shown to increase energy deposition in the wire core due to a longer resistive heating stage. The effect was observed both in single wire and wire array experiments. The evolution of the phase state of the wire material during explosion was examined by means of one-dimensional numerical simulation using a semiempirical wide-range equation of state describing the properties of tungsten with allowance made for melting and vaporization.Comment: 9 pages, 9 Postscript figure

Efficient Neutron Production from a Novel Configuration of Deuterium Gas-Puff Z-Pinch

A novel configuration of a deuterium z pinch has been used to generate fusion neutrons. Injecting an outer hollow cylindrical plasma shell around an inner deuterium gas puff, neutron yields from DD reactions reached Y-n = (2.9 +/- 0.3) x 10(12) at 700 ns implosion time and 2.7 MA current. Such a neutron yield means a tenfold increase in comparison with previous deuterium gas puff experiments at the same current generator. The increase of beam-target yields was obtained by a larger amount of current assembled on the z-pinch axis, and subsequently by higher induced voltage and higher energies of deuterons. A stack of CR-39 track detectors on the z-pinch axis showed hydrogen ions up to 38 MeV. Maximum neutron energies of 15 and 22 MeV were observed by radial and axial time-of-flight detectors, respectively. The number of DD neutrons per one joule of stored plasma energy approached 5 x 10(7). This implies that deuterium gas puff z pinches belong to the most efficient plasma-based sources of DD neutrons

The Construction of the Fast Resistive Bolometer for a SXR Measurement on the GIT-12 Facility

A lot of kinds of instruments are used for the SXR measurement at pulsed power facilities, but most of them are difficult to calibrate absolutely. For the determination of the energy of SXR radiated by the discharge on Z-pinches, it is possible to use the bolometer which can be calibrated analytically. The bolometer can be constructed with the sufficient sensitivity and, at the same time, with the time resolution in the order of nanoseconds. This bolometer was designed and constructed for the measurement on the 5MA facility GIT-12 at the Institute of High Current Electronics (IHCE) of the Siberian Branch Russian Academy of Sciences in Tomsk. The experiments on GIT-12 with the neon and deuterium gas-puff load were diagnosed by the copper bolometer with the time resolution of 4 ns and the sensitivity of 12 V cm2 J-1

Deuterium z-pinch as a powerful source of multi-MeV ions and neutrons for advanced

A novel configuration of a deuterium z-pinch has been used to generate a nanosecond pulse of fast ions and neutrons. At a 3 MA current, the peak neutron yield of (3.6 ± 0.5) × 1012 was emitted within 20 ns implying the production rate of 1020 neutrons/s. High neutron yields resulted from the magnetization of MeV deuterons inside plasmas. Whereas deuterons were trapped in the radial direction, a lot of fast ions escaped the z-pinch along the z-axis. A large number of >25 MeV ions were emitted into a 250 mrad cone. The cut-off energy of broad energy spectra of hydrogen ions approached 40 MeV. The total number of >1 MeV and >25 MeV deuterons were 1016 and 1013, respectively. Utilizing these ions offers a real possibility of various applications, including the increase of neutron yields or the production of short-lived isotopes in samples placed in ion paths. On the basis of our experiments with various samples, we concluded that a single shot would have been sufficient to obtain GBq positron activity of 13N isotopes via the 12C(d,n)13N reaction. Furthermore, the first z-pinch generated neutron radiograph produced by ≈20 ns pulses is presented in this paper

New Collective Quantified Goal on Climate Finance

Perspective Climate Research and ECBI have published a briefing note on Finding Common Ground on the New Collective Quantified Goal on Climate Finance (NCQG) that governments are expected to finalise in Baku in November at the 29th session of the Conference of the Parties to the UNFCCC (COP29). This explores the state of play of the negotiations, Parties’ priorities, and areas of contention, emphasising areas where common ground can be found and concrete progress achieved. For example, it focuses on, among others: structure of the new goal in view of the actions to be taken and scale of funding needed considering the needs and priorities of developing countries; contributor base and whether to expand it; access to and quality of finance; tracking delivery of the goal; and enhancing transparency. The note also briefly touches on the relationship between Article 9 (developed country support to developing countries) and Article 2.1c of the Paris Agreement in the context of the NCQG. Article 2.1c calls for “making finance flows consistent with a pathway towards low greenhouse gas emissions and climate-resilient development”. Some Parties see a relationship between Article 9 and Article 2.1c in the context of broadening the contributor base, while others fear it would shift responsibility to developing countries. The note acknowledges that the monetary number of the goal (or quantum) will be a political decision most likely taken in the final hours of Baku

International Climate Finance from a Global Perspective

The Paris Agreement reaffirmed the commitment to provide USD 100 billion in international climate finance to developing countries by 2020. This Working Paper delves into the history and challenges of international climate finance. We emphasize the complexities tied to diverse definitions and accounting practices, leading to disputes over climate finance figures, as well as the struggle of developed countries to meet the USD 100 billion annual target. With the need to mobilize finance for addressing loss and damage (L&D) gaining traction in UN climate negotiations, we examine how similar challenges may hinder progress on the L&D agenda. Furthermore, we stress the importance of fostering trust between donor and recipient countries in the context of financial support pledges under the Paris Agreement. We identify how key negotiation processes, like the New Collective Quantified Goal on Climate Finance (NCGG), have the potential to change the status quo

Catalysing private and public action for climate change mitigation: the World Bank’s role in international carbon markets

This policy analysis examines the role of the World Bank in shaping and stimulating international carbon markets. Adopting a public choice perspective, we argue that its engagement can be understood as a response to the joint goal of reputational and financial benefits. The detailed empirical account of the Bank’s activities – from its pioneering role through the Prototype Carbon Fund in the early 2000s, to its initiatives for upscaled crediting subsequent to the 2015 Paris Agreement – is broadly in line with this interpretation. The period between 2005 and 2011 most clearly shows that the Bank was ready to forego some reputational benefits for the sake of financial benefits. During this period, it followed a flourishing privately driven carbon market, mostly competing with, rather than catalysing, private activities. After the Paris Agreement opened the door for a new phase of carbon markets, the Bank again took up a pioneering role, now focusing on the public sector. However, since transparency in relation to its activities is limited – thus reducing reputational risk – these activities may not meet the quality standards, notably with respect to additionality, that are a precondition for carbon markets to be an effective tool for climate change mitigation

Do multilateral development bank trust funds allocate climate finance efficiently?

The Paris Agreement has been celebrated as a breakthrough for international climate policy. However, relatively scant attention has been given to the emergent ecosystem of climate finance facilities that support it. We provide an overview of the rising number of climate-related trust funds at multilateral development banks (MDBs). These funds can be distinguished into mitigation funds and adaptation funds. Some funds have a focus on capacity building activities. To maximize their effect on sustainable development, the different types of funds should follow different resource allocation criteria: For adaptation funds, vulnerability should represent the primary criterion. For mitigation funds, the main criterion should be the emission reduction potential. Capacity building should primarily focus on countries with weak institutions. Using a novel dataset of disbursements of climate-related trust funds, available for the World Bank, we examine whether fund allocations correspond to these expectations, and compare them with those of bilateral donors. We find that while trust funds with a focus on mitigation generally allocate aid in line with efficiency considerations, trust funds with a focus on adaptation do not seem to prioritize the countries most strongly in need, contrary to bilateral aid. Furthermore, capacity building activities do not seem to focus on countries with weak institutions. These findings have important implications for the effectiveness and legitimacy of climate aid to developing countries