Uranium-241 Isotope Created And Examined Via Multinucleon Transfer Reactions And Mass Spectrometry

April 15, 2023 by Maya Posch 11 Comments

A recent paper (PDF) in Physical Review Letters by T. Niwase and colleagues covers a fascinating new way to both create and effectively examine isotopes by employing a cyclotron and a mass spectrograph. In the paper, they describe the process of multinucleon transfer (MNT) and analysis at the recently commissioned KEK Isotope Separation System (KISS), located at the RIKEN Nishina Center in Japan.

Sketch of the KISS experimental setup. The blue- and yellow-colored areas are filled with Ar and He gases, respectively. Differential pumping systems are located after the doughnut-shaped gas cell as well as before and after the GCCB. (Credit: Niwase et al., 2023) — Sketch of the KISS experimental setup. The blue- and
yellow-colored areas are filled with Ar and He gases, respectively. Differential pumping systems are located after the doughnut-shaped gas cell as well as before and after the GCCB. (Credit: Niwase et al., 2023)

The basic process which involves the RIKEN Ring Cyclotron, which was loaded for this particular experiment with Uranium-238 isotope. Over the course of four days, ²³⁸U particles impinged on a ¹⁹⁸Pt target, after which the resulting projectile-like fragments (PLF) were led through the separation system (see sketch). This prepared the thus created ions to be injected into the multi-reflection time-of-flight mass spectrograph (MRTOF MS), which is a newly installed and highly refined mass spectrograph which was also recently installed at the facility.

Using this method, the researchers were able to establish that during the MNT process in the cyclotron, the transfer of nucleons from the collisions had resulted in the production of ²⁴¹U as well as ²⁴²U. Although the former had not previously been produced in an experimental setting, the mass of ²⁴²U had not been accurately determined. During this experiment, the two uranium as well as neptunium and other isotopes were led through the MRTOF MS instrument, allowing for the accurate measurement of the characteristics of each isotope.

The relevance of producing new artificial isotopes of uranium lies not so much in the production of these, but rather in how producing these atoms allows us to experimentally confirm theoretical predictions and extrapolations from previous data. This may one day lead us to amazing discoveries such as the famously predicted island of stability, with superheavy, stable elements with as of yet unknown properties.

Even if such astounding discoveries are not in the future for theoretical particle physics, merely having another great tool like MNT to ease the burden of experimental verification would seem to be more than worth it.

Building An Electron Microscope For Research

April 14, 2023 by Bryan Cockfield 10 Comments

There are a lot of situations where a research group may turn to an electron microscope to get information about whatever system they might be studying. Assessing the structure of a virus or protein, analyzing the morphology of a new nanoparticle, or examining the layout of a semiconductor all might require the use of one of these devices. But if your research involves the electron microscope itself, you might be a little more reluctant to tear down these expensive devices to take a look behind the curtain as the costs to do this for more than a few could quickly get out of hand. That’s why this research group has created their own electron detector.

Specifically, the electron detector is designed for use in a scanning electron microscope, which is typically used for inspecting the surface of a sample and retrieving a high-resolution, 3D image of it compared to transmission microscopes which can probe internal structures. The detector is built on a four-layer PCB which includes the photodiode sensing array, a series of amplifiers, and a power supply. All of the circuit diagrams and schematics are available for inspection as well thanks to the design being licensed under the open Creative Commons license. For any research team looking to build this, a bill of materials is also included, as is a set of build instructions.

While this is only one piece of the puzzle surrounding the setup and operation of an electron microscope, its arguably the most important, and also greatly lowers the barrier of entry for anyone looking to analyze electron microscope design themselves. With an open standard, anyone is free to modify or augment this design as they see fit which is a marked improvement over the closed and expensive proprietary microscopes out there. And, if low-cost microscopes are your thing be sure to check out this fluorescence microscope we featured that uses readily-available parts to dramatically lower the cost compared to commercial offerings.

Self-Cleaning Tech Could Help Solar Panels Keep Efficiency Up

April 14, 2023 by Zoe Skyforest 58 Comments

Solar panels are a special kind of magic — turning light into useful electrical energy. However, they don’t work nearly as well when they’re covered in dust, dirt, and grime. Conventional solutions involve spraying panels down with pure water, which is expensive and wasteful, or dry scrubbing, which can cause efficiency loss through scratching the panels. However, innovative new methods may offer useful solutions in this area, as shared by EETimes.

Researchers at MIT have explored the use of electrostatic methods to remove dust from solar panels. By creating a sufficiently strong electrostatic field, dust particles can be compelled to leap off of solar panels. The cleaning method requires no water and is entirely non-contact. It uses a motor system to pass a charged electrode past the surface of the panels, with the opposite charge applied to the panels themselves. This repels the dust from the panels and onto the moving electrode.

Other methods include the use of special “self-cleaning” glass manufactured with a laser etching technique. The method, referred to as Direct Laser Interference Patterning, or DLIP, creates microscopic features on the order of 300 nm to 30 um on the surface of the glass. The pattern creates a so-called “functional surface” from which dirt simply slides off. The laser-etched pattern has no negative impact on transparency.

If these ideas prove practical, expect them to take off quickly. Commercially viable technologies spread fast in the renewable space, as we’ve seen with the rapid uptake of floating solar farms in recent years.

The Challenges Of Producing Graphene In Quantity

April 12, 2023 by Maya Posch 26 Comments

We’ve all heard the incredible claims made about graphene and its many promising applications, but so far the wonder-material has been held back by the difficulty of producing it in large quantities. Although small-scale production was demonstrated many years ago using basic Scotch tape, producing grams or even kilograms of it in a scalable industrial process seemed like a pipedream — until recently. As [Tech Ingredients] demonstrates in a new video, the technique of flash Joule heating of carbon may enable industrial graphene production.

The production of this flash graphene (FG) was first demonstrated by Duy X. Luong and colleagues in a 2020 paper in Nature, which describes a fairly straightforward process. In the [Tech Ingredients] demonstration it becomes obvious how easy graphene manufacturing is using this method, requiring nothing more than carbon black as ingredient, along with a capacitor bank, vacuum chamber and a number of reasonably affordable items.

Perhaps best of all is that no refinement or other complicated processes are required to separate the produced graphene from the left-over carbon black and other non-graphene products. Using multiple of these carbon black-filled tubes in parallel, producing graphene could conceivably be scaled up to industrial levels. This would make producing a few kilograms of graphene significantly easier than coating hard drive platters with the substance.

Continue reading “The Challenges Of Producing Graphene In Quantity” →

Busting Wireless ESD Wrist Straps With LTT And ElectroBOOM

April 10, 2023 by Maya Posch 28 Comments

Nobody likes getting zapped from an electrostatic discharge, no matter whether you’re a fragile ASIC or a bag-of-mostly-salty-water humanoid. To prevent this, ESD wrist straps and similar are essential tools, as they prevent the build-up of a charge on your humanoid’s skin, essentially like a very large electrolyte-filled capacitor. Yet you can buy wireless ESD straps everywhere that are supposed to somehow dissipate this charge into the ether, even though this would seem to undermine the laws of physics that make capacitors work.

In a practical experimentation and assorted hijinks video collaboration by [Linus] from Linus Tech Tips and [Mehdi Sadaghdar] from ElectroBOOM put these wireless ESD straps to the test, featuring [Mehdi]’s DIY Van de Graaff generator to charge [Linus] up. What is excellently demonstrated in this video is how effective a real ESD strap is, and how the ‘wireless’ version is just a scam that does absolutely nothing to dissipate the charge, being just a waste of a 1 MOhm resistor and what could have been a real ESD strap.

Also covered in the video are what the reason for the resistor in an ESD strap is, and why metal bracelet type ESD straps are not appropriate, for very good reasons.

Continue reading “Busting Wireless ESD Wrist Straps With LTT And ElectroBOOM” →

Holograms: The Future Of Speedy Nanoscale 3D Printing?

April 9, 2023 by Dave Rowntree 7 Comments

3D printing by painting with light beams on a vat of liquid plastic was once the stuff of science fiction, but now is very much science-fact. More than that, it’s consumer-level technology that we’re almost at the point of being blasé about. Scientists and engineers the world over have been quietly beavering away in their labs on the new hotness, nanoscale 3D printing with varying success. Recently IEESpectrum reports some promising work using holographic imaging to generate nanoscale structures at record speed.

Current stereolithography printers make use of UV laser scanned over the bottom of a vat of UV-sensitive liquid photopolymer resin, which is chemically tweaked to make it sensitive to the UV frequency photons. This is all fine, but as we know, this method is slow and can be of limited resolution, and has been largely superseded by LCD technology. Recent research has focussed on two-photon lithography, which uses a resin that is largely transparent to the wavelength of light concerned, but critically, can be polymerized with enough energy density (i.e. the method requires multiple photons to be simultaneously absorbed.) This is achieved by using pulsed-mode lasers to focus to a very tight point, giving the required huge energy density. This tight focus, plus the ability to pass the beam through the vat of liquid allows much tighter image resolution. But it is slow, painfully slow.

Continue reading “Holograms: The Future Of Speedy Nanoscale 3D Printing?” →

The Sounds Emitted By Plants Are Real But They Are Still Not Talking

April 7, 2023 by Maya Posch 13 Comments

A recent paper published by researchers at the university of Tel Aviv in Cell on the sounds they captured from ‘stressed’ plants had parts of the internet abuzz with what this meant, with some suggesting that this was an early April Fools prank. The fun part here is the news item is not that plants make noise, but rather that this was the first time (apparently) that the noise made by plants was captured by microphones placed at some distance from a variety of plants.

This research is based on previous studies dating back decades, such as Tyree and Sperry who reported (PDF) in 1989 on the vulnerability of the plant xylem (water transporting tissue) to cavitation and embolism. Since the xylem’s function is to carry water and dissolved nutrients to the upper parts of the plant, having air bubbles form would be a negative thing for the plant’s survival. When and how cavitation occurs in the xylem is relevant as it directly impacts how well plants grow. Continue reading “The Sounds Emitted By Plants Are Real But They Are Still Not Talking” →