• Energy Research
• 7. Clean energy close
• 13. Climate action close
• English close
• University of North Texas close

A prototype ampere-class superconducting energy recovery linac (ERL) is under advanced construction at BNL. The ERL facility is comprised of a five-cell SC Linac plus a half-cell SC photo-injector RF electron gun, both operating at 703.75 MHz. The facility is designed for either a high-current mode of operation up to 0.5 A at 703.75 MHz or a high-bunch-charge mode of 5 nC at 10 MHz bunch frequency. The R facility serves a test bed for an envisioned electron-hadron collider, eRHIC. The high-current, high-charge operating parameters make effective higher-order-mode (HOM) damping mandatory, and requires to determination of HOM tolerances for a cavity upgrade. The niobium cavity has been tested at superconducting temperatures and has provided measured dipole shunt impedances for the estimate of a beam breakup instability. The facility will be assembled with a highly flexible lattice covering a vast operational parameter space for verification of the estimates and to serve as a test bed for the concepts directed at future projects. Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

A Marx-topology klystron modulator is under development for the International Linear Collider (ILC) project*. It is envisioned as a lower cost, smaller footprint, and higher reliability alternative to the present, bouncer-topology, baseline design. The application requires 120 kV (±0.5%), 140 A, 1.6 ms pulses at a rate of 5 Hz. The Marx constructs the high voltage pulse by combining, in series, a number of lower voltage cells. The Marx employs solid state elements; IGBTs and diodes, to control the charge, discharge and isolation of the cells. Active compensation of the output is used to achieve the voltage regulation while minimizing the stored energy. The developmental testing of a first generation prototype, P1, has been completed. This modulator has been integrated into a test stand with a 10 MW L-band klystron, where each is undergoing life testing. Development of a second generation prototype, P2, is underway. The P2 is based on the P1 topology but incorporates an alternative cell configuration to increase redundancy and improve availability. Status updates for both prototypes are presented. Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

Simulations of ion migration in the LCLS RF gun and injector A. Brachmann On behalf of the LCLS commissioning team The motivation for this work was the observed surface contamination of the first LCLS RF gun copper cathode. We will present the results of simulations in regards to ion migration in the LCLS gun. Ions of residual gases will be created by interaction of molecular gas species with the UV drive laser beam and by the electron beam itself. The larger part of those ionized molecules remain in the vicinity of creation, are transported towards beam line walls or away from the cathode. However a significant fraction gains enough kinetic energy to be focused by RF and magnetic fields, reaching the cathode and producing an undesirable increase of the cathode¿s surface work function. Although this fraction is small, during long term operation, this effect becomes a significant factor limiting the source performance. Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The Republic of Guinea has a rich and diversified hydrological potential. Several rivers in the sub region have their source. The hydrographic network comprises 1161 rivers, grouped into 23 watersheds. The country has 14 international rivers, including the Niger River, whose basin is shared by nine countries. Unfortunately, water resources are now threatened by anthropogenic activities of diverse origins (extensive agriculture, open-pit mining, illegal fishing, bush fires, making cooked bricks along streams, etc.) and the adverse effects of climate change. Moreover, the institutional and legal aspects are not conducive to the sustainable management of water resources. The impact of water shortage will be felt on all socio-economic activities. The agriculture sector is the main user of water in the country, droughts and recurrent floods have led to a decline in cereal food supplies. The country has a high hydroelectric potential (6,000 MW), unfortunately, only 6% of its potential is used. In order to meet its international commitments to reduce its greenhouse gas emissions, by 2030, the country will have to quintuple its hydroelectric production, which constitutes clean energy. The drinking water supply sector remains confronted with the low capacity of production and treatment of water. The management of water resources in the country is based on general plans for water development elaborated between 1978 and 1982. However, the country seeks to have a national policy for integrated water resources management and development of an action plan focusing on taking into account cooperation on shared watersheds.

In this paper, we analyzed the linac optics design requirement for a multi-pass energy recovery linac (ERL) with one or more linacs. A set of general formula of constrains for the 2-D transverse matrix is derived to ensure design optics acceptance matching throughout the entire accelerating and decelerating process. Meanwhile, the rest free parameters can be adjusted for fulfilling other requirements or optimization purpose. As an example, we design the linac optics for the future MeRHIC (Medium Energy eRHIC) project and the optimization for enlarging the BBU threshold. Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The management water resource in our States is harder and harder lately because of the frequency and of the intensity of droughts. Senegal, as most tropical States, knew an alternation of wet and dry periods. In this climatic context more and more disrupted by the anthropological activities, it is essential to analyze the dry episodes on various climatic domains, in diverse temporal scales and by diverse indications to propose to the populations of the measures of mitigation or adaptation regarding management of water. In this article, pluviometric data of six stations located in three climatic domains were analyzed. The analysis used and compared the values of the rainfall deviations decimal logarithm index (RDI), the rainfall anomalies index (RAI) and the standardized precipitation index (SPI) calculated for timescales of 5 years, of 25 years and of 50 years. The results indicate that the most remarkable droughts due to their intensity, their duration and their frequency occurred during decades 1970 and 1980 whatever the index, the timescale and the used climatic domain. These dry episodes reached their paroxysm in 1972 and 1983 with droughts of an extreme severity. The climatic domains are affected well by drought, but to varying degrees. Besides, it appears that the ISP index and the long-term timescale seems the best suited to describe with more precision the dry episodes in Senegal, and most affected continental Sahelian domain.

In this paper, we present a lattice design for the Large Hadron Electron Collider (LHeC) recirculating Linac. The recirculating Linac consists of one roughly 3km long linac hosting superconducting RF (SRF) accelerating cavities, two arcs and one transfer line for the recirculation. Electron beam will have two passes in the SRF linac to get a maximum energy of 140 GeV, or have four passes with a maximum energy of 60 GeV (two for acceleration and two for deceleration) in the Energy Recovery Linac (ERL) option. Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

We report on the design of a 7 cell, standing wave, 1.3 GHz LINAC cavity and the associated beam dynamics studies for the upgrade of the drive beamline for the Argonne Wakefield Accelerator (AWA) facility. The LINAC design is a compromise between single bunch operation (100 nC @ 75 MeV) and minimizing the energy droop due to beam loadning along the bunch train during bunch train operation. The 1.3 GHz drive bunch train target parameters are: 75 MeV, 10-20 ns macropulse duration, 16x60nC microbunches; this is equivalent to a macropulse current and beam power of 80 Amps and 6 GW, respectively. Each LINAC structure accelerates approximately 1000 nC in 10 ns by a voltage of 11 MV at an RF power of 10 MW. Due to the short bunch train duration desired (~10 ns) and the existing frequency (1.3 GHz), compensation of the energy droop along the bunch train is difficult to accomplish with the two standard techniques: time-domain or frequency-domain beam loading compensation. Therefore, to minimize the energy droop, our design is based on a large stored energy LINACs. In this paper, we present our LINAC optimization method, detailed LINAC design, and beam dynamics studies of the drive beamline. Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

Satellite based models to retrieve solar radiation have been in development over the past three decades. These models produce global horizontal irradiance (GHI) and direct normal irradiance (DNI) using models that follow either an empirical or physical approach. Although empirical methods have been used traditionally for computing surface radiation the advent of faster computing has made operational physical models viable. The Global Solar Insolation Project (GSIP) is an operational physical model from the National Oceanic and Atmospheric Admnistration (NOAA) that computes GHI using visible and infrared channel measurements from Geostationary Operational Environment Satellites (GOES). GSIP uses a two-stage scheme that first retrieves cloud properties, then uses those properties in a radiative transfer model to calculate surface radiation. The National Renewable Energy Laboratory (NREL), University of Wisconsin, and NOAA have collaborated to adapt GSIP to create a 4-km GHI and DNI product every 30 minutes. In this paper we present a short outline of the method, a comprehensive validation using high-quality ground-based solar data as well as results of ongoing improvements in the modeling. 28th European Photovoltaic Solar Energy Conference and Exhibition; 4029-4032

In this paper we present the design and prototype measurement of small gap (5mm to 10 mm aperture) dipole and quadrupole for the future high energy ERL (Energy Recovery Linac). The small gap magnets have the potential of largely reducing the cost of the future electron-ion collider project, eRHIC, which requires a 10GeV to 30 GeV ERL with up to 6 energy recovery passes (3.8 km each pass). We also studied the sensitivity of the energy recovery pass and the alignment error in this small magnets structure and countermeasure methods. Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan