Path: ...!3.eu.feeder.erje.net!feeder.erje.net!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!.POSTED!not-for-mail From: John R Walliker Newsgroups: sci.electronics.design Subject: Re: A better electron microscope Date: Sun, 11 Aug 2024 15:50:03 +0100 Organization: A noiseless patient Spider Lines: 51 Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Injection-Date: Sun, 11 Aug 2024 16:50:06 +0200 (CEST) Injection-Info: dont-email.me; posting-host="005dd2e7e7698cd71e36db27c7bb13f9"; logging-data="2296707"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX1/1B+syALaI2Lbcv6cnuRPvcN5zK9atZag=" User-Agent: Mozilla Thunderbird Cancel-Lock: sha1:u8Zqo2ATew0ehAxDwu1EQwFGN4k= Content-Language: en-GB In-Reply-To: Bytes: 3304 On 07/08/2024 08:29, Bill Sloman wrote: > On 7/08/2024 3:02 pm, Jan Panteltje wrote: >> Scientists revolutionize microscopy by reimagining the logic of imaging >>   https://www.sciencedaily.com/releases/2024/08/240801142229.htm >> >> New method significantly reduces the time and damaging radiation used >> to image fragile specimens >> Date: >>    August 2, 2024 >> Source: >>   Trinity College Dublin >> Summary: >>   Scientists have devised an innovative imaging method using >> state-of-the-art microscopes >>   that significantly reduces the time and radiation required. >>   Their work represents a significant breakthrough that will benefit >> several disciplines, >>   from materials science to medicine, as the method promises to >> deliver improved >>   imaging for sensitive materials such as biological tissues that are >> especially >>   vulnerable to damage. >> >> And chips? > > The paper claims "Giving microscopists the ability to 'blank' or > 'shutter' the electron beam on and off in a matter of nanoseconds in > response to real-time events has never been done before." > > It isn't true. The stroboscopic electron microscopes that Cambridge > Instruments sold from about 1983 as electron beam testers could deliver > a half-nanosecond wide pulse of electrons. > > The electron beam microfabrictors we'd been selling for year could turn > the beam on and off in less than 10nsec - I worked on the beam-blankers > for both. > > Scanning transmission microscopes do use higher voltage electrons, but > that just means that the electrodes that blank the beam have to be > longer. With a half nanosecond wide pulse, you couldn't make the plates > too long for 2kV electrons because the transit time got longer than the > blanking period and I had to invent a solution to get around that, but > "a matter of nanoseconds" give you more wiggle-room. > A bigger problem for biological tissues is that they have to be dried before they can be put in a vacuum chamber and this process can distort them. They also usually need to be stained with a heavy element such as uranium for TEM and coated with gold or other conductive materials for SEM. John