Electron Dump Research Articles

Recent H- ion source research and development at the Oak Ridge National Laboratory* *This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). This research was supported by the DOE Office ofScience, Basic Energy Science, Scientific User Facilities. The US government retains and thepublisher, by accepting the article for publication, acknowledges that

The U.S. Spallation Neutron Source (SNS) is a state-of-the-art neutron scattering facility delivering the world's most intense pulsed neutron beams to a wide array of instruments which are used to conduct investigations in many fields of science and engineering. Neutrons are produced from spallation of liquid Hg by bombardment of short (∼1 μs), intense (∼35 A) pulses of protons delivered at 60 Hz by a storage ring which is fed by a high-intensity, ∼1 GeV H- LINAC. This facility has operated almost continuously since 2006, with ion source performance increasing over those years, and currently providing 50–60 mA of H- ions with a duty-factor of 6% for maintenance-free runs of several months with near 100% availability. Ion source research and development at ORNL has played a key role in enabling and supporting this success: this report provides an update on some of the ongoing ion source research and development efforts which have been undertaken since the previous Negative Ion Beams and Sources (NIBS) conference in 2020. These include significant improvements to H- beam current by extraction from a larger source outlet aperture and improvements to the electron dumping system which should eliminate the gradual loss of electrode voltage over the course of a run which has occasionally impacted SNS operations. Improvement and simplification of the plasma ignition system for the external antenna ion source, a long-standing problem, was also realized. Lastly, RF coupling efficiency was measured for both the SNS internal and external antenna ion sources.

Radiation shielding and CuCr1Zr/Pb/PE and Fe/Pb/PE beam dump design for 220-MeV electron linear accelerator

This paper addresses the radiation issues, in particular the photon and neutron shielding, associated with the radiation shielding room and beam dump design for the 220-MeV electron linear accelerator. The energy deposition of a 220 MeV electron dump was investigated to determine the radius and length of the core of the dump with different materials. The angle of the primary shield relative to the beam direction was studied to design the perpendicular and lateral shield wall for the linear accelerator shielding room. In addition, the labyrinth design had been considered in this case. FLUKA Monte Carlo code has been computed to perform attenuation studies of photon and neutron radiation which were produced by the electromagnetic shower and photon interactions of materials. The prompt radiation fields which are photons and neutrons distributions in this design were observed. Two types of beam dump have been investigated. The first one is composed of CuCr1Zr, lead, and polyethylene. Another one is similar, but the first layer material was changed from CuCr1Zr to iron. The simulation results revealed that the beam dump and radiation shielding wall exhibit excellent performance in attenuating both photon and neutron radiation. The capability of beam dumps to absorb electron energy is well-designed. The dose distributions around the shielding room are below the design criteria, which can be applied to use for the 220-MeV electron linear accelerator.

Decision Tree Models for Predicting the Effect of Electronic Waste on Human Health

Informal processing of electronic waste has become one of the commonest sources of employment in developing countries which has contracted a great impact on human health due to the improper disposal of the heavy metals found in these waste materials. Several research works have been conducted to predict e-waste generation and management. Unfortunately, there is no study to predict the disease associated with the activities of informal e-waste products and their disposal. This study predicts the categorized disease of a person working and/or living at an electronic waste dump site based on their activities and their lifestyle using decision tree algorithms. The categorized diseases are skin, respiratory and reproductive diseases. The work compared the performance of C4.5 algorithm which used the Chi-squared test for tree pruning to handle overfitting with the Classification and Regression Tree (CART) algorithm which used tree depth control to handle overfitting. The C4.5 algorithm proved to be more effective than the CART algorithm. The study recommends that whenever two or more algorithms can be used to handle the same problem in principle, they should all be used and their results be compared.

Selenite bioreduction with concomitant green synthesis of selenium nanoparticles by a selenite resistant EPS and siderophore producing terrestrial bacterium.

Environmental bacterial isolates play a very important role in bioremediation of metals and toxic metalloids. A bacterial strain with high selenite (SeO32-) tolerance and reducing capability was isolated from electronic waste dump site in Banaras Hindu University, Varanasi, India. Based on 16S rRNA sequencing and BLAST search, this bacterial isolate was identified as Bacillus paramycoides and designated as strain MF-14. It tolerated Sodium selenite up to 110 mM when grown aerobically in LB broth and reduced selenite into elemental selenium (Se0) significantly within 24h with concomitant biosynthesis of selenium nanoparticles as clearly revealed by brick red precipitate and specific surface plasmon resonance peak at 210nm using UV-Visible spectrophotometer. Scanning electron microscopy (SEM) analysis of this bacterial strain exposed to 1mM and 5 mM selenite also demonstrated morphological alterations as cell enlargement due to accumulation and bioprecipitation of elemental selenium (Se0). The FTIR analysis clearly demonstrated that functional groups present on the surface of biogenic selenium nanoparticles (SeNPs) play a significant role in the stabilization and capping of SeNPs. Furthermore, these SeNPs were characterized using spectroscopic analysis involving Dynamic light scattering, zeta potential, XPS, FTIR, XRD and Raman spectroscopy which clearly revealed particle size 10-700nm, amorphous nature, stability as well as it's oxidation state. The biochemical studies have demonstrated that membrane bound reductase enzyme may be responsible for significant reduction of selenite into elemental selenium. Therefore, we may employ Bacillus paramycoides strain MF-14 successfully for bioremediation of selenite contaminated environmental sites with concomitant green synthesis of SeNPs.

Physicochemical characteristics of soil and water in electronic waste dump site, Alaba Lagos, Nigeria

Determination of physicochemical characteristics of soil and water adjoining dumpsites is important to ascertain the fitness of drinkable water and their public health implications. Following the paucity of information on this area of study, physicochemical characteristics of water and soil in electronic waste dump site, Alaba, Lagos, Nigeria. Six samples from the dumpsite made up of three soil and water respectively were collected and extracted using USEPA methods. One soil and water sample far from the dumpsite served as control. Physicochemical parameters of water and soil samples were determined using standard methods. Results show that pH of the water samples ranged from 4.81 to 7.30. SW1 had highest pH (slightly alkaline) while SW3 had lowest pH and was acidic. The electrical conductivity of SW1, SW2 and SW3 ranged from 61 µS to 1421 µS respectively. Water temperature was between 29.53 and 29.57oC. Total dissolved solid of the water ranged from 32.33 to 722 mg/L. Sulphate ranged from 238 mg/L to 314 mg/L. Phosphate ranged from 41.92 to 60 mg/L. Dissolved oxygen ranged from 0.93 to 2.4 mg/L. Similarly, soil pH ranged from 6.57 to 7.44. Soil temperature ranged from 28.43 to 30.7. Soil organic carbon ranged from 13.75% to 20.25% while the soil organic matter ranged from 17.88% to 26.32%. Soil particle distribution ranged from 58.56 – 87.52% sand, 3.22 – 13.79% clay and 8.84 – 27.65% slit. Some physicochemical characteristics of soil and water in sampled location did not follow the WHO standard. This study has informed the state of water available for consumption as well as the state of soil contamination. Proper care is required to checkmate this location to avoid future contaminations.

Optimization of Transmission X-ray Target for Intense Pulsed Electron Beam Accelerators

X-ray sources based on pulsed electron accelerators stimulate the development of bremsstrahlung converter designs. The numerical optimization of transmission-type X-ray targets for maximum X-ray output by pulsed electron beams was carried out in the present work. The targets featured a combination of a heavy element (tungsten or molybdenum) X-ray conversion layer and a titanium membrane that served as the vacuum window, thermal shielding for converter heat, and an electron dump. The energy spectrum of the electron beam generated via explosive emission was analyzed via the space-charge effect, and was utilized for the source sampling algorithm for electron transportation simulation with a Monte Carlo method for X-ray emission analysis. It was revealed that the transmission photon intensity of a mono-material target is primarily affected by the thickness of the target, and there exists an optimal target thickness within which the photon fluence is restricted by insufficient electron stopping; when exceeded, the extra thickness of the X-ray converter target imposes absorption and attenuates the generated X-ray. Analysis on dual-layer targets proved that this optimized converter target thickness, combined with a proper titanium window, produces the highest X-ray photon emissions.

Beam Formation Studies on the CERN IS03b H Source

An H- ion source is being operated at the new 160 MeV linear injector (Linac4) of the CERN accelerator complex. The source’s plasma is of the Radio Frequency Inductively Coupled Plasma type (RF-ICP), without magnetic cusp and runs with Cs-loss compensation [1]. Vertical downward oriented filter- and electron dump-dipolar magnetic fields expand over the plasma chamber, beam-formation, beam-extraction and electron dump regions and generate horizontal asymmetry and beam angular deflection partially compensated by mechanical alignment of the front-end. The H- beam is generated via volume and caesiated plasma surface modes, the latter inducing a radial asymmetry characterized by an increased current density close to the plasma electrode surface [2]. Asymmetries affecting the meniscus shape, or its current density have to be simulated via 3D Particle In Cell Monte Carlo (PIC-MC) solvers, such as the Orsay Negative Ion eXtraction code (ONIX) [3]. Validation of these simulations require dedicated measurements. This contribution describes experimental methods newly implemented at CERN’s ion source test stand and initial results for Optical and Beam Emission Spectroscopy (OES, BES), emittance and beam profile measurements. In a later stage, the gathered data sets can be compared to source plasma parameters and extracted beam parameters from PIC-MC simulations, once coupled to the Ion Beam Simulation (IBSimu) [4] beam transport code. The experimental parameter space includes RF-power, density of neutrals, position of the RF coil and extraction field. Beams of H-, D- and protons were produced; examples of measured data are presented in this contribution.

Key issues for the filament-arc ion source of EAST neutral beam injector toward high-power and long-pulse operation

Neutral beam injection is an effective plasma heating and current drive method for magnetic confinement devices. For supporting the high-confinement plasma operation of the fully superconducting tokamak EAST, a high-power and long-pulse neutral beam is foreseen to be injected into EAST. To achieve such a mission, the most important task is to develop a qualified ion source which can launch a positive ion beam for pulse length up to 100 s with the beam power larger than 2 MW. During the research and development on the EAST positive ion source, several key issues have been studied, including the heat load on electrode grids, the backstreaming electrons deposition, and the gas discharge efficiency. The capability of heat removal of the electrode grids has been demonstrated via a series of simulations and experiments. However, the backstreaming electrons deposition was extremely dense on the electron dump of the ion source, leading to its serious melting damage. According to the simulation of the trajectories of backstreaming electrons, the central magnets on the electron dump were removed as a preliminary solution. The melting damage was successfully avoided without the central magnets and the modified ion source has been operated without malfunction until now. But the total deposition of backstreaming electrons on the electron dump was increased and the magnetic confinement of primary electrons was reduced. Consequently, the arc efficiency was lower and the fraction of the neutral atoms with half beam energy was higher for the modified ion source.

Effect of Selected Electronic Waste Dump Sites on Quality of Surrounding Water Bodies in Abuja, Nigeria

Due to inappropriate management of vast amount of waste produced by various human activities, urban surface and ground water resources have been under danger of pollution. It is noted that solid waste management is a universal issue and that it is a growing source of worry in developed and developing countries due to the increase in urbanization, changes in consumer pattern, and industrialization which all directly transform to an increase in solid waste generation. The sampling points used of the research are Electronic Waste (e waste) dump sites of Guzape, Karmo and Kubuwa areas of Abuja with terrains of flowing surface water bodies/ pond water. The sample sites were chosen to investigate the impact of e-waste on the water quality of surrounding water bodies in the environment. Parameters measured from collected water samples are pH, Temperature, Conductivity, Turbidity, Dissolved Oxygen, Total Dissolved Solids, Total Suspended Solids, Calcium, Magnesium, Ammonia Nitrogen, Nitrate Nitrogen, Nitrite Nitrogen, Phosphate, Biochemical Oxygen Demand, Chemical Oxygen Demand, Bicarbonate, Manganese, Copper, Zinc, Lead, Cadmium and Chromium. Results showed heavy metal values for Cadmium and Manganese in the water samples were above the maximum permitted level as compared with standards for drinking water, it is inferred that the impact of E waste in the environment contributed to the presence of heavy metals in the water samples. Copper, Zinc, and Chromium were also detected in all water samples collect except for a sample with the absence of Chromium in the water sample.Key words: Disposal sites, Electronic waste, Water quality

Simulations of hybrid direct current radiofrequency (dc/rf) capacitively coupled plasmas

Effects of applying a high negative direct current (dc) voltage in argon capacitive coupled plasmas on the flux of secondary electrons (SEs) to a radiofrequency (rf) biased electrode and plasma uniformity were investigated using particle-in-cell Monte Carlo collision simulation and results were compared with experimental results. High energy SEs originating at electrodes with high negative dc voltage due to ion-impact as well as electron-impact were accelerated out of the sheath through the sheath voltage drop. These SEs gain energy equal to the applied dc voltage and either travel to the wafer electrode where they are lost (dumped) or are trapped between electrodes depending on the voltage on bottom electrode. Trapping and dumping of ballistic electrons depends on the magnitudes of the voltages (dc and rf) applied to each electrode. High energy SEs alter the electron energy distribution function at the wafer, high energy electron flux to the wafer and the plasma density profile. With the application of negative dc voltage, wafer receives high energy electron flux with energies up to applied dc voltage. For the range of conditions examined in this paper, the plasma density increases with the application of the negative dc voltage due to ionization by trapping of high energy SEs. The electrons that originate at the negative dc electrode minimize the impact of enhanced radial electric fields at the rf electrode edge allowing dc/rf plasmas to be center peaked even at low (13.56 MHz) rf frequencies.

H[formula omitted] extraction systems for CERN’s Linac4 H[formula omitted] ion source

Linac4 is a 160MeV linear H− accelerator at CERN. It is an essential part of the beam luminosity upgrade of the Large Hadron Collider (LHC) and will be the primary injector into the chain of circular accelerators. It aims at increasing the beam brightness by a factor of 2, when compared to the currently used 50MeV linear proton accelerator, Linac2.Linac4’s ion source is a cesiated RF-plasma H− ion source. Several beam extraction systems were designed for H− beams of 45keV energy, 50 mA intensity and an electron to H− ratio smaller than 5. The goal was to extract a beam with an rms-emittance of 0.25πmmmrad.One of the main challenges in designing an H− extraction system is dumping of the co-extracted electrons. Separating the electrons from the negative ions as early as possible reduces space-charge induced emittance-growth. However, a strong magnetic field close to the extraction might cause unnecessary strong deflection in a region of low beam energy. For this purpose a novel magnetic configuration was designed using a magnetic shield between the magnetic fields of the source and the electron dump, which conserves the filter field strength to keep the electron to H− ratio low and effectively dumps the co-extracted electrons. Magnetic configuration and beam trajectories were calculated using the TOSCA Opera 3D code and IBSimu, respectively. Three extraction systems will be discussed in terms of electron dumping efficiency, emittance and transport through the extraction system and LEBT to the RFQ and compared to the simulations.An improved emittance conservation through the extraction system and LEBT is predicted and further design improvements are proposed. Measurements show that the novel electron dump successfully traps the co-extracted electrons.

Review of particle-in-cell modeling for the extraction region of large negative hydrogen ion sources for fusion.

Particle-in-cell (PIC) codes are used since the early 1960s for calculating self-consistently the motion of charged particles in plasmas, taking into account external electric and magnetic fields as well as the fields created by the particles itself. Due to the used very small time steps (in the order of the inverse plasma frequency) and mesh size, the computational requirements can be very high and they drastically increase with increasing plasma density and size of the calculation domain. Thus, usually small computational domains and/or reduced dimensionality are used. In the last years, the available central processing unit (CPU) power strongly increased. Together with a massive parallelization of the codes, it is now possible to describe in 3D the extraction of charged particles from a plasma, using calculation domains with an edge length of several centimeters, consisting of one extraction aperture, the plasma in direct vicinity of the aperture, and a part of the extraction system. Large negative hydrogen or deuterium ion sources are essential parts of the neutral beam injection (NBI) system in future fusion devices like the international fusion experiment ITER and the demonstration reactor (DEMO). For ITER NBI RF driven sources with a source area of 0.9 × 1.9 m2 and 1280 extraction apertures will be used. The extraction of negative ions is accompanied by the co-extraction of electrons which are deflected onto an electron dump. Typically, the maximum negative extracted ion current is limited by the amount and the temporal instability of the co-extracted electrons, especially for operation in deuterium. Different PIC codes are available for the extraction region of large driven negative ion sources for fusion. Additionally, some effort is ongoing in developing codes that describe in a simplified manner (coarser mesh or reduced dimensionality) the plasma of the whole ion source. The presentation first gives a brief overview of the current status of the ion source development for ITER NBI and of the PIC method. Different PIC codes for the extraction region are introduced as well as the coupling to codes describing the whole source (PIC codes or fluid codes). Presented and discussed are different physical and numerical aspects of applying PIC codes to negative hydrogen ion sources for fusion as well as selected code results. The main focus of future calculations will be the meniscus formation and identifying measures for reducing the co-extracted electrons, in particular for deuterium operation. The recent results of the 3D PIC code ONIX (calculation domain: one extraction aperture and its vicinity) for the ITER prototype source (1/8 size of the ITER NBI source) are presented.

Assessment of PCBs and exposure risk to infants in breast milk of primiparae and multiparae mothers in an electronic waste hot spot and non-hot spot areas in Ghana

The aim of the study was to assess the levels of PCBs in the breast milk of some Ghanaian women at suspected hotspot and relatively non-hotspot areas and to find out if the levels of these PCBs pose any risk to the breastfed infants. A total of 128 individual human breast milk were sampled from both primiparae and multiparae mothers. The levels of PCBs in the milk samples were compared. Some of these mothers (105 individuals) work or reside in and around Agbogbloshie (hot-spot), the largest electric and electronic waste dump and recycling site in Accra, Ghana. Others (23 donor mothers) also reside in and around Kwabenya (non-hotspot) which is a mainly residential area without any industrial activities. Samples were analyzed using GC–MS/MS. The total mean levels and range of Σ7PCBs were 3.64ng/glipidwt and ˂LOD–29.20ng/glipidwt, respectively. Mean concentrations from Agbogbloshie (hot-spot area) and Kwabenya (non-hotspot areas) were 4.43ng/glipidwt and 0.03ng/glipidwt, respectively. PCB-28 contributed the highest of 29.5% of the total PCBs in the milk samples, and PCB-101 contributed the lowest of 1.74%. The estimated daily intake of PCBs and total PCBs concentrations in this work were found to be lower as compared to similar studies across the world. The estimated hazard quotient using Health Canada's guidelines threshold limit of 1μg/kgbw/day showed no potential health risk to babies. However, considering minimum tolerable value of 0.03μg/kgbw/day defined by the Agency for Toxic Substances and Disease Registry (ATSDR), the values of some mothers were found to be at the threshold limit. This may indicate a potential health risk to their babies. Mothers with values at the threshold levels of the minimum tolerable limits are those who work or reside in and around the Agbogbloshie e-waste site.

Control Topologies for 3-Phase SEIG used in Small Hydro Power Plant Feeding Isolated Domestic Load in Remote Mountainous Region

Objectives: This paper is to highlight the various control topologies used in 3-phase Self-Excited Induction Generator (SEIG) used in pico-hydro power generation system feeding isolated load. Methods/Statistical Analysis: The various topologies of these controllers which are also known as Electronic Load Controllers (ELC) include conventional as well as STATCOM based controllers using various power electronics devices for power system parameters regulations and power quality control. The Self-excited induction generators are most suitable for pico and micro hydro power generation systems feeding isolated load due to their advantages over conventional synchronous generators. Findings: In isolated mode of operation of self-excited induction generators, a suitable control is necessary to maintain the voltage & frequency of the generated output within permissible limits under varying loading conditions. This is achieved by using an Electronic Load Controller (ELC) and dump load in the system. The main aim of the control strategy is to control the voltage output of SEIG and to maintain the desired frequency of the generated output. These electronic load controllers regulate the dump load in the system so that total load seen by SEIG remains constant under varying consumer load conditions and thus maintaining the frequency of the system. From the analysis of various types of these controllers, it is found that simplest of the electronic load controller is conventional diode rectifier based ELC. However, it suffers with the problems of harmonics in the circuit. Modern ELCs use voltage source converters along with different transformer configurations for better power quality control and better voltage and frequency regulations under different operating conditions. Improvements: Fast computational capabilities of DSP are also used to control the STATCOM switches and chopper circuit in ELC for better and fast control. The use of different transformer configurations such as star-delta and zigzag type provide neutral path for 3-phase, 4-wire system apart from eliminating the 3rd harmonics in the system.

Soil concentrations of polybrominated diphenyl ethers and trace metals from an electronic waste dump site in the Greater Accra Region, Ghana: Implications for human exposure

Unregulated electronic waste (e-waste) recycling operations have become a significant environmental issue as well as human health risk in developing countries across the world. The present study evaluated the extent of pollution in Agbogbloshie e-waste recycling site in Accra, Ghana. The concentrations of polybrominated diphenyl ethers (PBDEs) and some selected trace metals were determined using gas chromatography electron impact ionization mass spectrometry and flame atomic absorption spectrophotometry, respectively. The concentrations of ∑ PBDEs ranged from 15.6 to 96.8ngg−1 dry weight, with an overall mean of 54.8ngg−1dw. BDE-28 was the dominant congener followed by BDE-209 and BDE-47. The order of mean concentrations of the abundant trace metals was Fe>Cu>Pb≫Mn, with a mean range of .531–289mgkg−1. Geoaccumulation index suggested that the surface soils deteriorated from moderate to high metal pollution, particularly for Cu, Pb and Fe. Of the trace metals analysed, Fe exhibited the highest concentration ranging from 3.97 to 918mgkg−1. Correlation and principal component analyses suggested possible interactions between PBDEs and the trace metals analysed, while source assessment suggested that PBDEs and trace metals were mostly derived from inputs from the e-waste recycling activities. Average daily dose (ADD) was estimated using concentrations corresponding to 5th percentile, median and 95th percentile. Hazard quotients of 380 and 862 were obtained for adults and children respectively, for Cu and Pb which is a cause for concern especially for local children.

Analysis of Energy Deposition on Ion Source Components of EAST Neutral Beam Injector

Neutral beam injection is one of the main auxiliary heating methods in controllable nuclear fusion experiments. During the operation of the EAST neutral beam injector, a large amount of energy is deposited on the ion source components, especially the electron dump (ED). In this paper, the energy deposited on the ion source components was analyzed in arc discharge mode and beam extraction mode indirectly by calculating the energy taken away by the cooling water. The results show that the ED has a large heat load: the average power density is almost 4.5 MW/m2 when the beam power is 3.3 MW. This research may lay the foundation for increasing the heat transfer capacity and guide the optimization of the ion source components in future work.

Electric and Electronic waste Dump sides causing Cadmium Contamination in Drinking water

Water occupies a very large area of the Earth's surface and also found underground. Most of the water on Earth's surface is found in Sea and Ocean and is saline. The availability of fresh water varies from place to place. Contamination of ground water occurs when pollutants are released to the ground water and make their way down. Metal including lead (Pb), Cadmium (Cd), Copper (Cu) and Mercury (Hg) can significant damage to environment and human health. Cadmium is one of the most trace metals in human food and water in the Whole World. This study was applied for the determination of Cadmium in 08 samples of groundwater and tap water from some districts of western U.P. viz Amroha, Meerut, Muzaffarnagar and Bijnaur. The researchers respective of their work determined the heavy metal concentration with the help of Atomic Absorption spectroscopy. Samples acidified to 1% with nitric acid and the stored in Double capped bottles. The aim of this study is to review the research work on concentration of heavy metal in ground water.

A Compact Mode Conversion Configuration in Relativistic Magnetron With a TE<sub>10</sub> Output Mode

A compact mode conversion configuration in A6 relativistic magnetron is proposed, and the magnetron operating in the π-mode can radiate axially with TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> mode through a rectangular waveguide which is designed to match the anode. This design, on the one hand, makes both the diameter and the axial length of the magnetron minimized, so that the volume of the coils of the applied magnetic field and the distance between the electron dump and the anode block can be reduced. On the other hand, it provides a much purer radiated mode in the output waveguide as a result of the limit to the dimension of the output waveguide for a certain frequency. In 3-D particle-in-cell simulation, the power conversion efficiency can reach 25.3%, corresponding to an output power of 436.0 MW and a resonant frequency of 2.52 GHz, at an applied voltage of 355 kV and an applied magnetic field of 0.4 T.

Design and R&D for manufacturing the beamline components of MITICA and ITER HNBs

The design of the beamline components of MITICA, the full prototype of the ITER heating neutral beam injectors, is almost finalised and technical specifications for the procurement are under preparation. These components are the gas neutraliser, the electrostatic residual ion dump, and the calorimeter. Electron dump panels are foreseen each side of the upstream end of the neutraliser to protect the cryo-panels from electrons, created by stripping and other processes, that exit the 1MeV accelerator. As the design of the components must fulfil requirements on the beam physics, insight on physical processes is required to identify performance trade-offs and constraints. The spatial gas distribution was simulated to verify the pumping requirements with electron dump panels and local conditions for breakdown voltage. Electrostatic analyses were carried out for the insulating elements of the RID to verify the limits of the electric field intensity. Different criteria were approached to investigate the fracture behaviour of ceramics considering the manufacturing implications and extrapolating the conditions for proof testing. Severe heating conditions will be applied steadily, as the maximum pulse duration is 1h, and cyclically so requiring to fulfil fatigue and ratcheting verifications. High heat fluxes, up to 13MW/m2 on the calorimeter, with enhanced heat transfer in subcooled boiling conditions will occur in the actively cooled CuCr1Zr panel elements provided with twisted tapes as turbulence promoters. Special R&D activities were undertaken to support the design: manufacturing of thick twisted tapes leading to an increased cooling performance while maintaining flow rate requirements, bending of swirl tubes, verification for permanent deformations due to stress relaxation after heating of swirl tubes, double side deep drilling of 2m long CuCr1Zr plates.

Geometry Design of an Electron Dump with Simple Geo

The goal of this study is to design a geometry of an electron dump with Simple Geo code which is a freeware product and provides the ability of designing complex geometric systems easily. Also, Simple Geo can output the designed geometry in many different formats. Desired design of the electron dump is to stop the 40 – 42 MeV electron beams. To reach this aim, requested geometric design with the possible material was done with Simple Geo and a FLUKA output format file created to run the simulations in FLUKA code.