Single Beamline Research Articles

X-ray multi-scale microfabrication system and x-ray imaging evaluation system all in one beamline

We have completed a system that can achieve both deep x-ray lithography and submicron x-ray lithography with a single beamline by introducing the combination of x-ray plane and cylindrical mirrors. This x-ray lithography system can provide a large-scale microfabrication processing with 210 × 300 mm2 (A4 size). To exploit multiscale lithography, the beamline has a beam transport vacuum duct with a two-stage stacked structure and a 5-axis stage. This two-stage stacked structure allows us to fabricate both micron scale structures with high aspect ratios and submicron scale structures using the same beamline. In addition, x-ray imaging and computer tomography (CT) system are connected to the x-ray lithography system for nondestructive inspection and evaluation of the fabricated microstructures. The x-ray imaging system constructed this study has a relatively low energy range of x-ray energy in the beamline, which is in the range of 2–15 keV or less. Therefore, relatively good absorption contrast can be obtained for plastic materials, biomaterials, and the like. Since nondestructive imaging of the processed shape by x-ray lithography is possible, it is a very useful system in processing and evaluation can be performed simultaneously. This system also enables us to obtain the live images with keeping the creature alive in liquid using an indirect x-ray imaging system which converts x-ray images to visible light images through the fluorescent plate.

Combining Laue diffraction with Bragg coherent diffraction imaging at 34-ID-C.

Measurement modalities in Bragg coherent diffraction imaging (BCDI) rely on finding a signal from a single nanoscale crystal object which satisfies the Bragg condition among a large number of arbitrarily oriented nanocrystals. However, even when the signal from a single Bragg reflection with (hkl) Miller indices is found, the crystallographic axes on the retrieved three-dimensional (3D) image of the crystal remain unknown, and thus localizing in reciprocal space other Bragg reflections becomes time-consuming or requires good knowledge of the orientation of the crystal. Here, the commissioning of a movable double-bounce Si (111) monochromator at the 34-ID-C endstation of the Advanced Photon Source is reported, which aims at delivering multi-reflection BCDI as a standard tool in a single beamline instrument. The new instrument enables, through rapidswitching from monochromatic to broadband (pink) beam, the use of Lauediffraction to determine crystal orientation. With a proper orientation matrixdetermined for the lattice, one can measure coherent diffraction patterns near multiple Bragg peaks, thus providing sufficient information to image the full strain tensor in 3D. The design, concept of operation, the developed procedures for indexing Laue patterns, and automated measuring of Bragg coherent diffraction data from multiple reflections of the same nanocrystal arediscussed.

Size measurement of Daphnia pulex using low-coherence Gabor digital holography

We measured the size of Daphnia pulex (D. pulex), which is an indicator organism used for examining toxicity, under freely-swimming and stress-free conditions, made possible by the post-focusing ability of digital holography (DH). This environmental measurement is a new application of DH. This implementation, which is a key point of this research, should be applicable to real on-site use in non-sterile and unstable mechanical situations. Through trial and error, we arrived at the simplest interferometer configuration using a single beam line that can withstand vibrations, a low-coherence light source for reducing coherent noise, and single-shot image capturing. Automatic size measurement based on DH with image processing was performed. The originality of this research is the quantitative size measurement and performance estimation achieved by comparing the results with those from conventional manual eye measurement using ordinary optical microscope observation and image processing software. The estimation also allowed us to determine the proper parameters in the image processing for DH measurement.

What Conditions Make Proton Beam Therapy Financially Viable in Western Canada?

BackgroundProton beam therapy (PBT) is available in many western and Asian countries, but there is no clinical, gantry-based PBT facility in Canada.MethodsA cost analysis was conducted from the Alberta Ministry of Health perspective with a 15-year horizon. Estimated costs were: PBT unit, facility development as part of an ongoing capital project, electricity, maintenance contract, and staffing. Revenues were: savings from stopping USA referrals, avoiding the costs of standard radiation therapy (RT) for Albertans receiving PBT instead, and cost-recovery charges for out-of-province patients.ResultsThe Ministry of Health funded 15 Albertans for PBT in the USA in the 2014/15 fiscal year (mean CAD$ 237,348/patient). A single-vault, compact PBT unit operating 10 hours/day could treat 250 patients annually. A 100 Albertans, with accepted indications, such as the curative-intent treatment of chordomas, ocular melanomas, and selected pediatric cancers, would likely benefit annually from PBT’s improved conformality and/or reduced integral dose compared to RT. The estimated capital cost was $40 million for a single beamline built within an ongoing capital project. Operating costs were $4.8 million/year at capacity. With 50% capacity reserved for non-Albertans at a cost recovery of $45,000/patient, a Western Canadian PBT facility would achieve net positive cash flow by year eight of clinical operations, assuming Alberta-to-USA referrals reach 21 patients/year by 2024 and increase at 3%/year thereafter. Sensitivity analysis indicates the lifetime net savings is robust to the assumptions made.ConclusionThis business case, based on Canadian costing data and estimates, demonstrates the potential for a financially viable PBT facility in Western Canada.

Beam dynamics validation of the Halbach Technology FFAG Cell for Cornell-BNL Energy Recovery Linac

The Cornell-BNL Electron Test Accelerator (CBETA), a 150 MeV energy recovery linac (ERL) now in construction at Cornell, employs a fixed-field alternating gradient optics return loop: a single beam line comprised of FFAG cells, which accepts four recirculated energies. CBETA FFAG cell uses Halbach permanent magnet technology, its design studies have covered an extended period of time supported by extensive particle dynamics simulations using computed 3-D field map models. This approach is discussed, and illustrated here, based on the final stage in these beam dynamics studies, namely the validation of a ultimate, optimized design of the Halbach cell.

Application of a three-lens slit spatial filter in high power lasers

Combined with partial parameters in National Ignition Facility, the conceptual design of off-axial four-pass main laser optical system with a three-lens slit spatial filter has been discussed. Since the three-lens slit spatial filter can decline the focal intensity by about 3 orders of magnitudes than that in NIF system, the cutoff frequency in main amplifier cavity can be reduced from 51 × DL to 39 × DL for better beam quality. The main laser system for single beam line can be shortened from 174.7 m to 155.7 m and the spatial filter in high vacuum becomes 60 m instead of the original 83.5 m. Additionally, the pinhole closure could be avoided since the declining of focal intensity in slit spatial filter and the absence of pinhole aperture in the other (pinhole) spatial filter, which provides new ideas for the future high-power lasers.

The SPECIES beamline at the MAX IV Laboratory: afacility for soft X-ray RIXS and APXPS.

SPECIES is an undulator-based soft X-ray beamline that replaced the old I511 beamline at the MAX II storage ring. SPECIES is aimed at high-resolution ambient-pressure X-ray photoelectron spectroscopy (APXPS), near-edge X-ray absorption fine-structure (NEXAFS), X-ray emission spectroscopy (XES) and resonant inelastic X-ray scattering (RIXS) experiments. The beamline has two branches that use a common elliptically polarizing undulator and monochromator. The beam is switched between the two branches by changing the focusing optics after the monochromator. Both branches have separate exit slits, refocusing optics and dedicated permanent endstations. This allows very fast switching between two types of experiments and offers a unique combination of the surface-sensitive XPS and bulk-sensitive RIXS techniques both in UHV and at elevated ambient-pressure conditions on a single beamline. Another unique property of the beamline is that it reaches energies down to approximately 27 eV, which is not obtainable on other current APXPS beamlines. This allows, for instance, valence band studies under ambient-pressure conditions. In this article the main properties and performance of the beamline are presented, together with selected showcase experiments performed on the new setup.

HiPER laser architecture principles

The HiPER project [1] is in a preliminary phase and a risk assessment is being conducted for a generic HiPER beamline concept – this is based on an anticipated requirement for a single beamline (or focal spot unit) drawn from the best available knowledge we have to date of the fusion physics requirement. For the moment the general architecture is to first order independent of the specific beamline implementation (i.e compression phase or ignition phase) as the fundamental requirements are very similar. In this paper we are describing the laser beamline as a bundle of unit beams (or beamlets) and we are explaining that optical zooming is quite possible especially in the case of shock ignition.

Demonstration of high-energy 2ω (5265 nm) operation on the National Ignition Facility Laser System

A single beamline of the National Ignition Facility (NIF) has been operated at a wavelength of 526.5 nm (2 omega) by frequency converting the fundamental 1053 nm (1 omega) wavelength with an 18.2 mm thick type-I potassium dihydrogen phosphate (KDP) second-harmonic generator (SHG) crystal. Second-harmonic energies of up to 17.9 kJ were measured at the final optics focal plane with a conversion efficiency of 82%. For a similarly configured 192-beam NIF, this scales to a total 2 omega energy of 3.4 MJ full NIF equivalent (FNE).

The TIL commissioning and performance

The TIL serves for both technological platforms for SG-III construction and physical experiments to study and understand target physics toward ignition and plasma burning [2]. The TIL has been designed to produce 10kJ blue light. Its eight-beam are stacked 4 high by 2 wide, The clear optical aperture is 30cm×30cm The cavity and booster amplifiers have 9 and 6 glass slabs respectively, with thickness of 3.8cm. The cavity is a four-pass amplification stage with the seed pulse injected through its cavity spatial filter, while the booster a single pass amplification stage. The commissioning experiments have successfully been conducted to test the output and control abilities of the system. A single beam line of TIL produced 3-ns pulse of 1645 Joule blue light at the target, which demonstrated that the TIL can deliver ten-thousand-joule blue light to the target. Beam qualities have been investigated jointly with the laser chain simulations using the SG-99 code. The wavefront distortions of the beams will be improved by deformable mirrors.

CLS ID-10 chicane configuration: From “Simple Sharing” to extended performance with high-speed polarization switching

The chicane scheme adopted for the elliptically polarized undulators (EPU) in the ID10 section at the Canadian Light Source (CLS) not only permits independent operation of two beamlines, but also allows to redirect beams from two EPUs into a single beamline with a performance similar to a “dedicated” configuration. Fast switching at kHz rates will be achieved by piezo shutters located after exit slits which will block the light of alternate polarization.

The LIL facility quadruplet commissioning

Following LIL single beamline commissioning in 2003, where performance in terms of power and energy required for LMJ was demonstrated, we spent year 2004 to qualify the quadruplet (or quad) performance at 1ω/3ω. Over that year, the first quad high power and high energy laser experiments took place on LIL facility. A careful set of test campaigns were conducted to safely ramp up laser performance. The main goal was to measure quad-specific features such as beam synchronization and focal spot (size, smoothing contrast ratio or irradiation nonuniformity σ rms ) versus the LMJ requirements. LIL Quad beam waist was recorded for various pulse durations, smoothing techniques and for a wide range of laser intensities up to LMJ-nominal ones. Now, LIL quad has been commissioned to the center of the target chamber and the first plasma experiments are made.

High energy negative-ion based neutral beam injection system for JT-60U

Abstract On the basis of recent progress in the research and development of a high current and high energy negative-ion source, the construction of a 500 keV negative-ion based neutral beam injection (NBI) system for JT-60U has begun to demonstrate a mega-amp level NB current drive at high plasma density and to study high energy beam heating in reactor-grade plasmas. The specification of the NBI system is as follows: a beam energy of 500 keV, an injection power of 10 MW, a beam duration time of 10 s, beam species of deuterium or hydrogen. The neutral beam of 10 MW is injected in a tangential codirection with a single beamline that has two negative ion sources. The construction of the negative-ion based NBI system will be completed in 1996, and NB current drive and plasma core heating experiments will start immediately in JT-60U.

Long pulse neutral beam system for the Tokamak Physics Experiment

Abstract The Tokamak Physics Experiment (TPX) is planned as a long-pulse or steady-state machine to serve as a successor to the Tokamak Fusion Test Reactor (TFTR). The neutral beam component of the heating and current drive systems will be provided by a TFTR beamline modified to allow operation for pulse lengths of 1000 s. This paper presents a brief overview of the conceptual design which has been carried out to determine the changes to the beamline and power supply components that will be required to extend the pulse length from its present limitation of 1 s at full power. The modified system, like the present one, will be capable of injecting about 8 MW of power as neutral deuterium. The initial operation will be with a single beamline oriented co-directional to the plasma current, but the TPX system design is capable of accommodating an additional co-directional beamline and a counter-directional beamline.

Effect of time-dependent development process on the limit of proximity exposure compensation in electron beam lithography

In our earlier papers, it was pointed out that the limit of proximity exposure compensation (PEC) in electron beam lithography using the dose correction technique is achieved if the dose correction factors are derived from the electron energy dissipation distribution (EED) at a depth in the resist where it has maximum lateral spread. The energy threshold criterion for the development process was used (this implicitly assumes a time-independent development process), to show that under such limiting PEC the resist edge slope of isolated and closely spaced line patterns becomes nearly equal to the edge slope of a single beam line. In this paper we show the effect of a time-dependent development process on the resist edge slope and pattern dimensional accuracy, when PEC is at its limits. The two developers 1:3 MIBK:IPA and MIBK are considered. A two-step development process which combines the advantages of the two developers is shown to provide much better control over the resist edge slope, pattern dimensional accuracy and process flexibility. Finally, the results of different time-dependent development processes are compared with the results when the energy threshold criterion is used for the development process.

Induction linac drivers for heavy ion fusion

The Heavy Ion Fusion Accelerator Research (HIFAR) program of the U.S. Dept. of Energy has for several years concentrated on developing linear induction accelerators as Inertial Fusion (IF) drivers. This accelerator technology is suitable for the IF application because it is readily capable of accelerating short, intense pulses of charged particles with good electrical efficiency. The principal technical difficulty is in injecting and transporting the intense pulses while maintaining the necessary beam quality. The approach used has been to design a system of multiple beams so that not all of the charge has to be confined in a single beam line. The beams are finally brought together in a common focus at the target. This paper will briefly present the status and future plans of the program, and will also briefly review systems study results for HIF.

On dose correction in electron beam lithography

Ideal proximity exposure compensation is shown to occur when the dose correction factors are obtained by considering the electron energy dissipation distribution at the lowest plane in the resist. In such an ideal situation, the simulation of resist profiles in line patterns shows that the resist edge slope becomes nearly equal to what can be obtained with a single beam line.

Vacuum pumping of multimegawatt neutral beam injection lines

Neutral beam injection lines employed for heating large tokamak and mirror plasmas have a unique gas pumping requirement, which is to maintain a high pressure (∼10−3 Torr) in the gas cell neutralizer and a low pressure (∼10−6 Torr) downstream after the neutralizer. Large hydrogen gas inputs (a few tens of Torr l/s) needed for operating an ion source and also the packing of multiple ion sources in a single beamline indeed make the beamline pumping a technological challenge, requiring a pumping speed greater than 106 l/s. We have witnessed, as beamlines get bigger, that beamline pumping techniques have shifted from conventional to gettering, and then to cryocondensation pumping. Cryopumping techniques are now employed in almost every beamline for high speed pumping; cryopanel design varies widely since the panels are an integral part of a beamline. A brief review is given of the beamline pumping technology, covering such topics as gas loading characteristics, vacuum components, cryopumping techniques, gettering techniques, and reactor relevant implications.

Vulcan - A versatile high-power glass laser for multiuser experiments

This paper reports the design and characterization of the newly upgraded Nd:glass laser facility at the Rutherford Laboratory. Emphasis is placed on the unusual aspects consequent on its role as a multiuser facility, where reliability and flexibility are of paramount importance. The basic facility configuration is of two high-power laser systems in parallel-a six-beam laser for implosion experiments and a separate high-power single beamline for either X-ray backlighting diagnostics of implosion experiments or use in a separate single-beam target area. Additional flexibility is provided by remotely controlled changeover mirrors enabling groups of amplifiers to be used in different combinations for various energies and shot repetition rates. Either a mode-locked or a Q -switched oscillator can be selected to provide a range of pulse durations from 50 ps to many nanoseconds. Harmonic generation is used routinely to give a choice of wavelengths for different experiments. The six-beam system is normally run at the second harmonic, although the fundamental wavelength is also available, while the single-beam target area can use fundamental, second, or third harmonics.

Laser beam brightness improvement with high power spatial filtering

Combined with partial parameters in National Ignition Facility, the conceptual design of off-axial four-pass main laser optical system with a three-lens slit spatial filter has been discussed. Since the three-lens slit spatial filter can decline the focal intensity by about 3 orders of magnitudes than that in NIF system, the cutoff frequency in main amplifier cavity can be reduced from 51 × DL to 39 × DL for better beam quality. The main laser system for single beam line can be shortened from 174.7 m to 155.7 m and the spatial filter in high vacuum becomes 60 m instead of the original 83.5 m. Additionally, the pinhole closure could be avoided since the declining of focal intensity in slit spatial filter and the absence of pinhole aperture in the other (pinhole) spatial filter, which provides new ideas for the future high-power lasers.