A negativeionbased neutral beam injection nbi system started its operation in 1998 with two injectors in the large helical device lhd, which is the worldlargest superconducting helical system, and the third injector was operational in 2001. Before considering the problem of long pulse neutral beam. During the last twenty five years various modifications and upgrades of the system were. The jet neutral beam injection nbi system is undergoing an upgrade of both beam power and pulse duration, which.
Neutral beam injection is recognized as one of the most effective means of plasma heating. Design study of a 120kev, 3 he neutral beam injector. The nb cell also hosts other systems like the vvpss boxes and lines, the remote handling systems for the hnbs, all the cooling pipes and cable trays for the hnbs, some diagnostics systems etc. Study of the power supply system for the acceleration grids.
It is operated at energy 50 kev, equivalent beam current for hydrogen up to i a, pulse duration of up to 4 s. The dnbi is capable of providing a beam of hydrogen atoms of 50 kv maximal energy, with an equivalent beam current of up to 1 a. It is funded by fusion for energy, iter international organization and italy. It is widely recognized that neutral beam injection nbi, i. Citeseerx steady state diagnostic neutral beam injector. Diagnostic neutral beam injector how is diagnostic neutral. The dose equivalent rates outside the engineering test facility neutral beam injector shield from the induced radioactivity have been calculated for the reactor operating at 1140 mw for 1, 30, and 365 days. How does an ion source works in a neutral beam injector. A neutral beam injector is essentially a particle accelerator. The positive ion based source with a hot cathode based arc chamber and a tetrode accelerator was employed for a neutral beam injector on the experimental advanced superconducting tokamak east.
Development of a core snubber for the neutral beam. The constraint that limits operating life when injecting he is its high sputtering rate. Neutral beam the system that makes the tokamak feel small. Pdf conceptual design of the demo neutral beam injectors. Physics design of the injector source for iter neutral beam. Damba, beam transmission monitoring of the tjii neutral beam injectors, european master of science in nuclear fusion physics and engineering erasmus mundus programme, 2014. Conceptual design of the beam source for the demo neutral. May 11, 2017 embodiments provided herein are directed to systems and methods for a negative ionbased neutral beam injector. High power neutral beam injector has been developed with particle energy of 25 kev, a current of 60 a, and several. The injector will be operated without cryopumps in a volume pumped configuration, and should provide 0.
In these devices, a beam of negative ions 40 a is accelerated up to 1mev by a set of grids having increasing potentials. If we want to develop the required power 10 mw per beam line, currents around 40 a are necessary. Conceptual design of the beam source for the demo neutral beam. Research, design, and development needed to realise a neutral. The iter domestic agencies of india and japan are also contributors and partners. By tangential injection in the torus, neutral beams also provide momentum to the plasma and current drive, one essential feature for long pulses of burning plasmas. According to the latest physics design of the china fusion engineering test reactor cfetr, two neutral beam injectors nbis, which deliver a total of 40 mw in not less than 3600 s with 1 mev d0. The hnbs and the diagnostic nb injector are to be located in the neutral beam cell nb cell, which is an 11 000 m 3 room in the iter tokamak building.
Preliminary design of diagnostic system for negative. In this plan, we designed the maximum beam energy 125ke v for hydrogen and. Optimization of the accelerators for the iter neutral beam injector project vanni antoni, piero agostinetti, marco cavenago1, hubert p. This paper discusses the scientific and technical requirements for a neutral beam injection system on the fast tokamak and describes a preliminary conceptual design of a suitable injector. Each neutral beam injector port 3 heating neutral beam injector hnb and one diagnostic neutral beam injector dnb is equipped with the internal duct liner. The beam power will deposit on the beam collimator due to the beam divergence and it will. Performance of upgraded jet neutral beam injectors sciencedirect. To provide a beam for active beam emission spectroscopy measurements in large fusion devices a dedicated neutral beam injector was developed. Translation find a translation for diagnostic neutral beam injector in other languages. Schematic of a neutral beam injection heating system see also figure 9. The dose rates at one day after shutdown are large even after one day of operation. The diagnostic neutral beam injector dnbi for the tcv tokamak, plasma physics institute, lausanne, was developed and commissioned by the binp team in 1999. Then, the beam is neutralized and injected into the iter vacuum vessel, heating the plasma by collision with plasma particles.
The lhd negativenbi system is arranged tangentially in which one injector has the opposite injection. Neutral beam injectornbifor the demo fusion reactor, is currently being. The peak neutral beam power density from a single injector is shown in fig. Optimization of the accelerators for the iter neutral beam.
A nonresonance photoneutralizer for negative ionbased neutral beam injectors. Neutral beam injection nbi is one method used to heat plasma inside a fusion device. Steady state diagnostic neutral beam injector core. The target values of east neutral beam injector nbi are beam energy 5080kev, injection beam total power 24 mw, beam pulse width 10100s. Its function is to deliver highenergy particles to the heart of the plasma. Neutral beam injector for active plasma spectroscopy. The facility will host the fullscale prototype of the reactors neutral beam injector, mitica, and a smaller prototype of its ion source, spider. Iter will be equipped with two heating neutral beam injectors with a provision of a third injector and a neutral beam line for diagnostic purposes. Neutral beam injection was developed in the late 70ties and is now the main heating method for most of the fusion experiments worldwide. The negative ionbased neutral beam injector comprises an ion source, an accelerator and a neutralizer to produce about a 5 mw neutral beam with energy of about 0. Neutral beam injection is a flexible and reliable technique, which has been the main heating system on a large variety of fusion devices. Us10375814b2 photon neutralizers for neutral beam injectors. The sputtering is partly controlled by using an extra grid to prevent ion flow from the neutralizer duct to the electron suppressor grid, but a tradeoff between beam current and operating life is still. Status of the start neutral beam injection project.
Highpower injection with negativeionbased neutral beam. Pdf neutral beam injector for active plasma spectroscopy. Schematic diagram of a neutral beam heating system negative ion neutral beam injection ninbi is shematically equal to pinbi. The waves penetrate the plasma and transfer their energy to the constituent particles. Design of a neutral beam injection system for storu. Negative ion based neutral beam injection iopscience. Conceptual design of the demo neutral beam injectors.
Design of a neutral beam injection system for storu presented by sam posen on june 7, 2009 at the cap congress in moncton division of plasma physics project supported by nserc and completed partially in fulfillment of the requirements of the engineering physics undergraduate program at queens university. Two neutral beam injectors nbi are foreseen to provide a substantial fraction of the heating power necessary to ignite thermonuclear fusion reactions in iter. Citeseerx document details isaac councill, lee giles, pradeep teregowda. Neutral beam injector dnb is equipped with the internal duct liner. The neutral beam injection system for lhd is scheduled to construct a 15 mw system by the end of fy 1998. The injector is also capable of providing beam modulation with. The development of the nbi system at unprecedented parameters 40 a of negative ion current accelerated up to 1 mv requires the realization of a full scale prototype, to be tested and optimized at the test facility under construction. New design of neutral beam injector for the heat load in. The peak power density in the jetsize case rises rapidly as the beam envelope size.
The trap is preferably formed by two smooth mirror surfaces facing each other with at least one of the mirrors being concave. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed. The main functions of the duct liner are to protect the vv wall from the highpower neutral beam, limit the beam. A conceptual design of the neutral beam injector nbi for the demo fusion reactor, is currently being developed by consorzio rfx in collaboration with other european research institutes. The injection of high energy neutral beams is one of the main tools to heat the plasma up to fusion conditions. The injector is also capable of providing beam modulation with frequency of up to 500 hz. Pdf long pulse neutral beam injection researchgate. Apr 02, 2017 i am not a total nbi expert, but i picked up a few things when writing about the polywell and lockheeds cfr. In iter, to heat the plasma, the contribution of 2 or 3 neutral beam injectors nbi is necessary.
The neutral beam injector of claim 9 wherein the photon trap comprises a confinement region adjacent a family of normals common to the first and second mirror surfaces. In the former, electromagnetic waves are directed by antennas at the surface of the plasma. Ep3221865a4 photon neutralizers for neutral beam injectors. The neutral beam injector of claim 9 wherein the photon trap is spherical, elliptical, cylindrical or toroidal in shape. Active steering system for the neutral beam injector for iter. Dose rates from the induced activity in the etf neutral beam. If that doesnt work, you will have to copy extreme injector v3. Requirements specification for the neutral beam injector on. New design of neutral beam injector for lhd kaneko, 0. Measurement of key parameters for east neutral beam injector.
The major modification to the nbi beamline has been the installation of an optical fiber coupled control and instrumentation system. Neutral beam injection relies on beams of highspeed, highenergy atoms that penetrate into the plasma, initiating collisions and transferring their energy. The main functions of the duct liner are to protect the vv wall from the highpower neutral beam, limit the beam dimensions, shield the field welded joints between the port components to allow their re. Depending on the location and operating time, cooling times from 30 days to. Introduction the jet nbi system consists of two neutral injector boxes nibs equipped each with up to 8 pinis 1. Iter is planning two onemillionvolt mv, 40a heating neutral beam injectors and is making a space reservation for a possible third as well as a smaller neutral beam line 100 kv, 60a for diagnostic. The nonresonance photoneutralizer utilizes a nonresonant photon accumulation, wherein the path of a photon becomes tangled and trapped in a certain space region, i. Neutral beam injection is an efficient heating mechanism and it has the current drive efficiency required in a reactor. Fast is being proposed as a european experiment in support to the operations on iter and to the design of demo. Preliminary design of diagnostic system for negative neutral. The influence of neutral beam optimization for demo on.
321 908 757 197 718 1436 558 586 1271 511 1088 779 832 1547 547 4 278 101 606 1022 1170 605 364 1367 124 928 1100 139 520 1319 618 1250 125 442 951 847 332 358 1191 625 961