Sergey Kutsaev

Improved charge breeding efficiency of light ions with an electron cyclotron resonance ion source

The Californium Rare Isotope Breeder Upgrade is a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS). The facility utilizes a (252)Cf fission source coupled with an electron cyclotron resonance ion source to provide radioactive beam species for the ATLAS experimental program. The californium fission fragment distribution provides nuclei in the mid-mass range which are difficult to extract from production targets using the isotope separation on line technique and are not well populated by low-energy fission of uranium. To date the charge breeding program has focused on optimizing these mid-mass beams, achieving high charge breeding efficiencies of both gaseous and solid species including 14.7% for the radioactive species (143)Ba(27+). In an effort to better understand the charge breeding mechanism, we have recently focused on the low-mass species sodium and potassium which up to present have been difficult to charge breed efficiently. Unprecedented charge breeding efficiencies of 10.1% for (23)Na(7+) and 17.9% for (39)K(10+) were obtained injecting stable Na(+) and K(+) beams from a surface ionization source.

Design of RF power coupler for superconducting cavities

A new power coupler has been designed and is being prototyped by Argonne National Laboratory (ANL) for use with any of the ANL proposed superconducting (SC) half- or quarter-wave cavities for SARAF [1] and Project-X [2]. The 50 Ohm coaxial capacitive coupler is required to operate in the CW regime with up to 15 kW of forward power and under any condition for the reflected power. A key feature is a moveable copper plated stainless steel bellows which will permit up to 3 cm of axial stroke and adjustment of the external quality factor by roughly one order of magnitude in the range of 105 to 106. The mechanical and vacuum design includes two ceramic windows, one operating at room temperature and another at 70 Kelvin. The two window design allows the portion of the coupler assembled onto the SC cavity in the clean room to be compact and readily cleanable. Other design features include thermal intercepts to provide a large margin for RF heating and a mechanical guide assembly to operate cold and under vacuum with high reliability.

MIXI: Mobile Intelligent X-Ray Inspection System

A novel, low-dose Mobile Intelligent X-ray Inspection (MIXI) concept is being developed at RadiaBeam Technologies. The MIXI concept relies on a linac-based, adaptive, ramped energy source of short X-ray packets of pulses, a new type of fast X-ray detector, rapid processing of detector signals for intelligent control of the linac, and advanced radiography image processing. The key parameters for this system include: better than 3 mm line pair resolution; penetration greater than 320 mm of steel equivalent; scan speed with 100% image sampling rate of up to 15 km/h; and material discrimination over a range of thicknesses up to 200 mm of steel equivalent. Its minimal radiation dose, size and weight allow MIXI to be placed on a lightweight truck chassis.

High speed, low dose, intelligent X-ray cargo inspection

The security market requirements for high throughput rail cargo radiography inspection systems include better than 5 mm line pair imaging resolution, penetration beyond 400 mm steel equivalent, scan speeds of up to 60 km/h, material discrimination (four groups of Z) in 100 % of cargo at speeds reaching 45 km/h, low dose and small radiation exclusioi zone. In order to achieve these requirements, which cannot be met by conventional dual energy radiography systems, a team lead by RadiaBeam Technologies, LLC (RBT) has initiated a research into new radiography methods and imaging detector materials with the goal of developing an Adaptive Railroad Cargo Inspection System (ARCIS). The ARCIS technical concept relies on linac-based, adaptive, ramped energy source of packets of short X-ray pulses sampled by a new type of fast X-ray detectors with rapid hardware processing for intelligent linac control, and advanced radiography image processing and material discrimination analysis. The following ARCIS key enabling technologies overcome the limitations of the conventional dual energy interlaced cargo inspection systems: Multi-energy material discrimination in a single scan line provided by packets of short pulses from an X-ray source with end-point energy ramp up (> 1 MHz rate of energy switching); Real-time intelligent setting of packets maximum energy depend on X-ray attenuation in cargo; Fast Scintillation-Cherenkov detectors with reduced sensitivity to scatter radiation; Detector readout with Silicon Photomultiplier (SiPM) provides time-resolving of short X-ray pulses; Self-control adaptive dynamic adjustment of SiPM responsivity in detector channel for increased dynamic range.

Electron linac with deep energy control for Adaptive Rail Cargo Inspection System

A novel high speed Adaptive Railroad Cargo Inspection System (ARCIS) is being developed at RadiaBeam Technologies. The ARCIS concept relies on linac-based, adaptive, ramped energy source of short X-ray packets of pulses, a new type of fast X-ray detectors, rapid processing of detector signals for intelligent control of the linac, and advanced radiography image processing. The requirements for this system include better than 5 mm line pair resolution, penetration greater than 400 mm of steel equivalent, scan speeds up to 60 km/h, material discrimination within 100% of image and minimal average dose. To meet these requirements a new S-band travelling wave linac with deep energy control has been designed. This paper discusses the linac design approach and its principal components, as well as engineering and manufacturing aspects.

Heavy ion linear accelerator for radiation damage studies of materials

A new eXtreme MATerial (XMAT) research facility is being proposed at Argonne National Laboratory to enable rapid in situ mesoscale bulk analysis of ion radiation damage in advanced materials and nuclear fuels. This facility combines a new heavy-ion accelerator with the existing high-energy X-ray analysis capability of the Argonne Advanced Photon Source. The heavy-ion accelerator and target complex will enable experimenters to emulate the environment of a nuclear reactor making possible the study of fission fragment damage in materials. Material scientists will be able to use the measured material parameters to validate computer simulation codes and extrapolate the response of the material in a nuclear reactor environment. Utilizing a new heavy-ion accelerator will provide the appropriate energies and intensities to study these effects with beam intensities which allow experiments to run over hours or days instead of years. The XMAT facility will use a CW heavy-ion accelerator capable of providing beams of any stable isotope with adjustable energy up to 1.2 MeV/u for 238U50+ and 1.7 MeV for protons. This energy is crucial to the design since it well mimics fission fragments that provide the major portion of the damage in nuclear fuels. The energy also allows damage to be created far from the surface of the material allowing bulk radiation damage effects to be investigated. The XMAT ion linac includes an electron cyclotron resonance ion source, a normal-conducting radio-frequency quadrupole and four normal-conducting multi-gap quarter-wave resonators operating at 60.625 MHz. This paper presents the 3D multi-physics design and analysis of the accelerating structures and beam dynamics studies of the linac.

MEBCIS: Multi-energy betatron-based cargo inspection system

The security market requirements for state-of-the-art mobile and portal radiography inspection systems include high imaging resolution (better than 5 mm line pair), penetration beyond 300 mm steel equivalent, material discrimination (three groups of Z) at speeds up to 16 km/h with 100% image sampling, low dose and small radiation exclusion zone. New research into radiography methods and systems has been actively pursued in order to achieve these challenging requirements. Recently, a significant portion of the R&D effort has been devoted to re-examining betatron based X-ray inspection systems. The advantages of the betatron-based inspection systems over conventional linac-based designs include small focal spot (which improves resolution), low weight and form-factor, a simpler control system and relatively low cost. A novel, low-dose Multi-Energy Betatron-based Cargo Inspection System, MEBCIS, presented in this paper relies on an innovative technique of extracting two X-ray pulses with lower-and higher-energies within a single betatron acceleration cycle (in contrast to conventional dual-energy betatrons with one X-ray pulse produced during separate betatron acceleration cycles). In addition to the new betatron, new types of fast X-ray Scintillation-Cherenkov detectors, rapid processing of detector signals, an adaptive detector feedback algorithm for control of the betatron, and algorithms for intelligent material discrimination are parts of the overall MEBCIS system. The key advantage of the MEBCIS concept is that the material discrimination data is acquired in a single scan line rather than two. Thus, for the same betatron pulse rate, the scan rate can be twice as fast (better throughput) or can be done with a lower dose, even without adaptive dynamic pulse adjustment. Application of these techniques will maximize material discrimination, penetration, and contrast resolution while simultaneously reducing dose to the environment, resulting in a smaller exclusion zone. Its minimal size and weight will allow MEBCIS to be placed on a lightweight truck chassis.