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At least 19 records

Modified eddy current probe having a faraday shield

A modified eddy current (MEC) probe includes a probe body having a bore formed therein. A printed circuit board (PCB) assembly includes a circuit board defining a plane, has a plurality of electronic components mounted thereon, and is configured for mounting within the bore of the probe body. A coil board assembly is electrically connected to the PCB assembly, defines a plane, and includes a first coil board layer, a second coil board layer bonded to the first coil board layer, a transmitter coil formed on an outside surface of the first coil board layer, a Faraday shield formed on an outside surface of the second coil board layer, and a sensor coil formed on one of an inside surface of the first coil board layer and the second coil board layer, such that the sensor coil is positioned between the first coil board layer and the second coil board layer. The plane of the coil board assembly is arranged orthogonally to the plane of the circuit board.

47 OTHER INSTRUMENTATION↗

Modified eddy current probe for low conductivity surfaces

A modified eddy current (MEC) probe includes a probe body having a bore formed therein. A printed circuit board (PCB) assembly includes a circuit board defining a plane, has a plurality of electronic components mounted thereon, and is configured for mounting within the bore of the probe body. A coil board assembly is electrically connected to the PCB assembly and comprises a coil board defining a plane, a transmitter coil formed on a first side of the coil board, and a sensor coil formed on second side of the coil board. The plane of the coil board is arranged orthogonally to the plane of the circuit board.

42 ENGINEERING↗

Peripheral end face attachment of exposed copper layers of a first printed circuit board to the surface of a second printed circuit board by surface mount assembly

A printed circuit board (PCB) structure and mounting assembly for joining two PCBs. A first PCB has a top and bottom surface faces and a peripheral end face separating the top and bottom surface. The first PCB has one or more conductive wire ends exposed at a surface of the peripheral end face; the exposed conductive wire ends forming multiple separate electrical contacts across the thickness and length of the PEF surface. A second PCB has a top surface face and one or more conductive pads exposed at the top surface at locations corresponding to locations of the multiple electrical contacts. A surface mount solder material is disposed on one or more exposed conductive pads for electrically connecting with corresponding the multiple electrical contacts. The disposed solder material stably joins the PEF surface of the first PCB to the top surface of the second PCB in a relative perpendicular orientation.

Takken, Todd E.↗

Peripheral end face attachment of exposed copper layers of a first printed circuit board to the surface of a second printed circuit board by surface mount assembly

A printed circuit board (PCB) structure and mounting assembly for joining two PCBs. A first PCB has a top and bottom surface faces and a peripheral end face separating the top and bottom surface. The first PCB has one or more conductive wire ends exposed at a surface of the peripheral end face; the exposed conductive wire ends forming multiple separate electrical contacts across the thickness and length of the PEF surface. A second PCB has a top surface face and one or more conductive pads exposed at the top surface at locations corresponding to locations of the multiple electrical contacts. A surface mount solder material is disposed on one or more exposed conductive pads for electrically connecting with corresponding the multiple electrical contacts. The disposed solder material stably joins the PEF surface of the first PCB to the top surface of the second PCB in a relative perpendicular orientation.

Takken, Todd E.↗

X-ray Inspection Model Validation with Physical Dosimetry

A non-functional printed circuit board assembly was developed using ULTIboard and a simple computational transport model was created for use with the Monte Carlo software MCNP. EBT 3 film radiography was used to compare with Monte Carlo simulation to validate the board representation. The computational transport model was then revised to include connection pins, solder balls, highly attenuating internal structures, and copper trace distribution. Results from the revised model were compared to the EBT 3 films to observe improvements to dose profiles. It was found that this method was useful in verifying the placement of components, as the dose profiles were observed to follow the same trends. The experiment was then repeated using XRQA 2 films to achieve the same level of contrast with 1% the dose of EBT 3 films. It was found that high contrast may be achieved using these films to identify major issues with the model geometry, at a cost of dose profile accuracy. A second validation method was applied to the model using 37 CaF 2 thermoluminescent dosimeters (TLDs). TLD measurements were compared with the simplified and complex transport models to identify the features that have the greatest impact on simulation accuracy. The TLD calibration to CaF 2 was found to be accurate within 5.6%, while calibration to dose in Si was found to be accurate within 4.7%. Finally, it was observed that the accurate representation of solder balls and proper modeling of highly attenuating internal structures had the greatest impact on simulation accuracy.

61 RADIATION PROTECTION AND DOSIMETRY↗

Optimized Viewing Techniques to Minimize Radiation Damage From X-ray Imaging Systems

X-ray inspection of ball grid arrays (BGAs) is typically performed at one or more viewing angles to examine adhesion sites for errors such as voids, joint cracking, or head-in-pillow. During this inspection process, the cir cuit board assembly is subject to ionizing radiation exposure, which can cause trapped charge within oxide layers of semiconductor devices. Some x-ray machines allow for programmable inspection routines, which could be used to optimize radiation exposure to semiconductor components. Using Monte Carlo methods, x-ray inspection of a BGA was simulated to determine a range of acceptable viewing angles. Dose rates to circuit board components were estimated at each inspection angle to determine the view resulting in optimized radiation exposure. Results showed that for each BGA, the maximum unobstructed viewing times without exceeding a 5 Gy dose limit to a single part ranged from 82 to 94 minutes. Using a radiation cost function method, optimized viewing across all components was found. Here, it was observed that for a consistent dose limit applied to silicon-based components, performing inspection with BGAs facing the x-ray source was optimal. A third method was applied, assigning individual dose limits based on empirical data from the NASA Goddard Space Flight Center radiation database. This method showed that optimized viewing maximizes the distance between the radiation source and highly sensitive components. It was also observed that cumulative effects from viewing two BGAs will influence viewing angles, causing the optimal view of one BGA to exist nearly 180° from the other.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Microbead Encapsulation for Protection of Electronic Components

Here, this study investigates the application of microbeads as an innovative encapsulation technique to protect electronic components from harsh mechanical strain. Traditional encapsulation methods using hard epoxy provide substantial mechanical support but create thermal expansion mismatch issues, potentially leading to electronic component failure. We explore the use of finely powdered microbeads to achieve protective structures combining stiffness and energy absorption. The research focuses on key variables, including microbead size, microbead roughness, compaction of microbeads, and circuit board mounting in the encapsulation, all of which influence the encapsulation’s effectiveness. Experimental setups and testing protocols were developed to assess the performance of various microbead materials under different impact conditions. Results demonstrate that microbead encapsulation significantly reduces strain on circuit boards, minimizing the risk of damage during mechanical shocks. However, challenges remain, such as optimizing microbead characteristics and modeling their behavior within large-scale circuit board assemblies. Despite these challenges, the findings suggest that microbead encapsulation offers a promising alternative to conventional methods, enhancing the durability and reliability of electronic components in high-stress environments.

42 ENGINEERING↗

Device and method to manipulate ions in multi level system

An apparatus includes multiple levels of ion transport channels, with successive levels coupled by elevator channels. Efficient three dimensional packing provides long path lengths in practical volumes for ion mobility separation with high resolving power. Disclosed elevator configurations provide efficient routing of ion transport channels across levels with low ion loss, enabling ion mobility separation over 100 levels or more. Elevator configurations include (i) opposed traveling waves meeting at an elevator entrance, (ii) external elevator with a wrap-around electrode bank, (iii) external elevator with electrode banks on parallel extension plates, or (iv) elevator operating in surfing mode, in various combinations. Manufacture is aided by printed wiring boards, with interchangeable boards. Assembly with motherboard, spacer block(s), and alignment pins provides efficient distribution of electrode excitations and accurate reproducible positioning.

Ibrahim, Yehia M.↗

Device and method to manipulate ions in multi-level system

An apparatus includes multiple levels of ion transport channels, with successive levels coupled by elevator channels. Efficient three dimensional packing provides long path lengths in practical volumes for ion mobility separation with high resolving power. Disclosed elevator configurations provide efficient routing of ion transport channels across levels with low ion loss, enabling ion mobility separation over 100 levels or more. Elevator configurations include (i) opposed traveling waves meeting at an elevator entrance, (ii) external elevator with a wrap-around electrode bank, (iii) external elevator with electrode banks on parallel extension plates, or (iv) elevator operating in surfing mode, in various combinations. Manufacture is aided by printed wiring boards, with interchangeable boards. Assembly with motherboard, spacer block(s), and alignment pins provides efficient distribution of electrode excitations and accurate reproducible positioning.

Ibrahim, Yehia M.↗

Laser Based Ultrasound for Verification of Circuit Card Assemblies

This IR is a follow-up conference Paper to the IR approved abstract; PNNL-SA-194096. --- Verification that equipment is authentic and not changed; even at the circuit card assembly (CCA) level will likely be an important component of future arms control treaties. This effort was an initial evaluation of the potential for laser-based ultrasound (LBU) as an inspection tool for Unique Identification (UID) of Circuit Card Assembly (CCA) boards and CCA components. The LBU system used a laser pulse for ultrasound generation and an Optical Microphone for ultrasound detection to image subsurface structures without physical contact and in a dry state. This paper described the selected CCA surrogate, CCA components that were examined, the LBU system, LBU images of the CCA components, and the initial development of UID algorithms. Receiver operating characteristics (ROC) curves indicated good performance for two algorithms as a potential means for UID of CCA boards and CCA components.

Laser Ultrasound, Equipment Verification, Arms Con↗

Optimizing Adhesion: Evaluating B-Stage Epoxy for Bonding [Poster]

The application of increased pressure during the curing process of B-stage epoxy has been hypothesized to enhance the adhesive properties and bond strength in printed wiring board (PWB) assembly. This study aimed to investigate the correlation between pressure application and the performance of B-stage epoxy.

42 ENGINEERING↗

Evacuated Spheres for Closed-Cell Vacuum Insulation

Insulation materials with a thermal resistance per inch higher than 6h∙ft 2 ∙°F/Btu∙in or R6/in (42m∙K/W) are needed for building envelope retrofits in which solutions with slim profiles are required because of minimal available space or because real estate has a premium cost. These insulation materials will also be of benefit to prefabricated construction given that slim designs either reduce shipping costs or increase the floor space provided to the customer. Vacuum insulation panels (VIPs) are the current state-of-the-art insulation material with a resistance of about R35/in (243m∙K/W); however, their use in buildings is hindered by the fact that damages to their protective film decrease their performance to ≤R8/in (56m∙K/W). Given the lack of robust, highly-insulating materials, we are exploring methods to develop evacuated spheres that can act as a closed-cell vacuum insulation. The evacuated spheres could be assembled into boards that could attain ~R14/in (97m∙K/W). Advantages that evacuated spheres will offer over VIPs are that they will likely be more suitable for construction because punctures will only cause localized damage, and that the boards could be cut into customized shapes. We are currently investigating two processes to evacuate spheres to produce polymeric vacuum insulation spheres (PVISs) and coated and evacuated insulation spheres (CEISs). PVISs involve the extrusion of economical polymers, blowing agents, and gas barriers. CEISs use naturally-occurring or synthesized hollow particles with porous shells that are evacuated and coated with a gas impermeable thin film. Both manufacturing processes aim for very large throughputs to ensure cost-effectiveness and adoption by the construction industry. This paper discusses the manufacturing techniques that we are exploring and our progress to date.

Hun, Diana E.↗

Solder assembly of pins to the peripheral end face of a printed circuit board

A printed circuit board (PCB) and PCB assembly. The PCB is formed of a laminate substrate of at least two layers of a non-conductive material forming at least one peripheral end face (PEF) surface separating top and bottom PCB surfaces. Embedded conductive wiring at one or more multiple layers carry energy to or from PCB surface mounted devices. The conductive wiring provides multiple conductive wire ends exposed at multiple locations along the PEF. A conductive contact structure is formed at the PEF surface to connect with one or more of the exposed conductive wire ends. One or more conductive pins are attached to the conductive contact at the PEF and are configured to mount the PCB on, and in a vertical and perpendicular orientation or a coplanar orientation relative to, a surface of a second PCB surface. The conductive pins provide one or more of: an electrical, thermal and/or mechanical contact.

Takken, Todd E.↗

System and methods for deploying payloads

Embodiments of the present invention include systems for launching primary or secondary payloads or actuating other launch vehicle or payload or instrumentation devices. The system includes an adapter assembly and at least one sequencer mounted to the adapter assembly. The sequencer includes: controller boards, each of the controller boards having a controller for controlling deployment of the payloads and data files; output ports coupled to the controller boards and configured to transmit signals from the controller boards to dispensers therethrough, deployment mechanisms containing the payloads, the adapter assembly having channels for accommodating the dispensers; and a detector coupled to the controller boards and adapted to detect an external signal and, in response to the external signal, to send an initiation signal to the controller boards. The system also includes at least one power supply coupled to the sequencer and adapted to provide an electrical power to the sequencer.

42 ENGINEERING↗

Sensor assemblies and methods for emulating interaction of entities within water systems

Sensor assemblies are provided for use in modeling water systems. These sensor assemblies can be used as sensor fish. These assemblies can include a circuit board supporting processing circuitry components on either or both opposing component support surfaces of the circuit board and a housing above the circuit board and the components, with the housing being circular about the circuit board in at least one cross section, and wherein the supporting surfaces of the circuit board are substantially parallel with the plane of the housing in the one cross section. Methods for emulating interaction of entities within water systems are provided. The methods can include introducing a sensor assembly into a water system. The sensor assembly can include: a circuit board supporting processing circuitry components on either or both of opposing component support surfaces of the circuit board; a housing about the circuit board and the components, the housing being circular about the circuit board in at least one cross section; and wherein the support surfaces of the circuit board are substantially parallel with the plane of the housing in the one cross section.

Deng, Z. Daniel↗

The CLAS12 Silicon Vertex Tracker

Silicon Vertex Tracker (SVT) has been designed for the CLAS12 spectrometer using single-sided microstrip sensors fabricated by Hamamatsu Photonics. The sensors have a graded angle design to minimize dead areas and a readout pitch of 156 um, with intermediate strips. Each double-sided SVT module hosts three daisy-chained sensors on each side with a full strip length of 33 cm. There are 512 channels per module, read out by four Fermilab Silicon Strip Readout (FSSR2) chips, featuring data-driven architecture, mounted on a rigid–flex hybrid board. The modules are assembled in a barrel configuration using a unique cantilevered geometry to minimize the amount of material in the tracking volume. This paper is focused on the design, qualification of the performance, and experience in operating and commissioning the tracker during the first year of the data taking.

47 OTHER INSTRUMENTATION↗

Characterization of a silicon photo-multiplier array with summing board as a photo-multiplier tube replacement in organic scintillator assemblies

In this work, we report on the energy, timing, and pulse-shape discrimination performance of cylindrical 5.08 cm diameter x 5.08 cm thick and 7.62 cm diameter x 7.62 cm thick trans-stilbene crystals read out with the passively summed output of three different commercial silicon photo-multiplier arrays. Our results indicate that using the summed output of an 8 x 8 array of SiPMs provides performance competitive with photo-multiplier tubes for many neutron imaging and correlated particle measurements. For a 5.08 cm diameter x 5.08 cm thick crystal read out with SensL’s ArrayJ-60035_64P-PCB, which had the best overall properties, we measure the energy resolution as 17.8 ± 0.8% at 341 keVee (σ/E), the timing resolution in the 180–400 keVee range as 236 ± 61 ps (σ), and the pulse-shape discrimination figure-of-merit as 2.21 ± 0.03 in the 230–260 keVee energy range. For a 7.62 cm diameter x 7.62 cm thick crystal read out with SensL’s ArrayJ-60035_64P-PCB, we measure the energy resolution as 21.9 ± 2.3% at 341 keVee, the timing resolution in the 180–400 keVee range as 518 ± 42 ps, and the pulse-shape discrimination figure-of-merit as 1.49 ± 0.01 in the 230–260 keVee energy range. Our findings enable many scintillator-based instruments to enjoy the size, robustness, and power benefits of silicon photo-multiplier arrays as replacement for the photo-multiplier tubes that are predominantly used today.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Single channel PICOSEC Micromegas detector with improved time resolution

This paper presents design guidelines and the experimental verification of a single-channel PICOSEC Micromegas (MM) detector with an improved time resolution. The design encompasses the detector board, vessel, auxiliary mechanical parts, and electrical connectivity for high voltage (HV) and signals, focusing on improving the stability, reducing noise, and ensuring signal integrity to optimize timing performance. A notable feature is the simple and fast reassembly procedure, facilitating quick replacement of the detector internal components that allows for an efficient measurement strategy involving different detector components. The paper also examines the influence of parasitic capacitance and inductance on the output signal integrity. To validate the design, a prototype assembly and three interchangeable detector boards with varying readout pad diameters were manufactured. Detectors were initially tested in the laboratory. Finally, the timing performance of the detectors with different pad sizes was verified using 150 GeV muons. Notably, a record time resolution for a PICOSEC Micromegas detector technology with a CsI photocathode of 12.5 ± 0.8 ps was achieved for a detector with 10 mm diameter readout pad size.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗