Re: A better electron microscope

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