Let there be light! Fiat lux!

Researchers advocate for use of UV light in Covid-19 disinfection

According to an article in Electro Optics Magazine, researchers have advocated for the use of ultraviolet light as a 'particularly efficient, easily deployable, and economically affordable' means to limit the spread of coronavirus.

Based on a paper in ACS Publications "Back to Normal: An Old Physics Route to Reduce SARS-CoV-2 Transmission in Indoor Spaces" authored by a group of international scientists. The study suggests that small indoor spaces such as toilets, elevators, and office pantries, which are used only intermittently but involve a high turnover of people, could be protected through exposure to a high intensity of UVC radiation while not in use. The same approach could be used in public transportation, with periodic irradiation cycles after a certain number of stops or time of continuous use. A similar concept could be applied to motion-inactivated UVC illumination that would serve as a protective barrier in passageways and corridors.

fluorescent lamps, microcavity plasmas, and LED

The study gives information on the currently available UVC sources, such as fluorescent lamps, microcavity plasmas, and LEDs, emphasising that, by irradiating this type of light inside the ventilation systems of buildings and in shared indoor spaces while not in use, it is possible to quickly and efficiently deactivate airborne and surface-deposited Sars-Cov-2 viruses. (text from Electro Optics magazine)

Related posts:

Seven Materials

We measured seven materials in the deep UV with a McPherson VUV Spectrophotometer. Click the image to better see. The spectrophotometer operates under vacuum or purge to prevent O2 and H2O absorbance. It also has independent control over detector angle and sample angle of incidence. Use the McPherson VUV to measure coatings theta 2-theta, diffraction grating efficiency, off-angle scatter with ease in the 120~350 nm range.

VUVAS 2000 VUVAS 2000

We measured ~2 mm thick calcium fluoride, strontium fluoride, barium fluoride, sapphire, and several different grades of fused silica in the 120~220 nanometer wavelength range with a deep UV spectrophotometer

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Thermal Scans for Entry

New sensor compatibility expands the range of wavelengths where McPherson spectrometers detect mid- and long-wave infrared light; increasing utility for spectroscopy and imaging applications in chemistry, biology, aerospace and defense. Infrared spectrometers provide spectroscopic capability to interrogate the feature-rich region of long-wave infrared. They are delivered with diffraction gratings selected for your application (up to 20 microns long-wave infrared (LWIR). Gold, silver and other optical coatings enhance performance in the IR. They also now provide ample, accessible space and a mechanically robust platform for mounting infrared arrays. Pictured here, a bolometer array IR digital camera mounted on a one meter focal length McPherson spectrometer. This array can sort fifty infrared bands simultaneously when properly mounted on the spectrometer. More sensitive applications use infrared cameras with thermoelectric or cryogenic cooling - they easily fit too.

imaging cameras could play critical role in keeping people safe One meter focal length, optically fast, f/7 spectrometer / spectrograph

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How UV light may protect us from the coronavirus

I've been asked, and also wondered ... Does the broadband UV radiation in natural sunlight sterilize or even 'kill' Covid-19? After all, it is strong enough to cause skin damaging sunburn and sometimes results in cancers. According to the World Health Organization (WHO) the answer is a definitive "No".

From WHO : "Exposing yourself to the sun or to temperatures higher than 25C degrees DOES NOT prevent the coronavirus disease (COVID-19) . . . You can catch COVID-19, no matter how sunny or hot the weather is.

To protect yourself, make sure you clean your hands frequently and thoroughly and avoid touching your eyes, mouth, and nose.

More from WHO

world health graphic about UV disinfection

The title of this post come from an article in Yahoo news and I believe originated in the LA Times. The closing paragraphs of the article lead with “Can I disinfect my stuff with UV from sunlight?”. Check it out if you want to hear more about it. General queries about this subject on LinkedIn didn't produce results.

You might ask, "How does ultraviolet light kill cells?.

#uv #uvc #ultraviolet #worldhealthorganization #who #coronavirus #covid19

What is VUV?

Vacuum Ultra Violet Spectroscopy

Why do we need a high vacuum for VUV system?

Wavelengths below 200 nanometers are known by many names. Because of the very strong absorption of air (especially oxygen and water vapor) and therefore the need to evacuate the experimental environment, this spectral range is called Vacuum Ultra Violet (VUV). Vacuum Ultra Violet (VUV) is blocked by most atmospheric gases and may propagate through partially transparent gases such as nitrogen or argon. The VUV region is bounded by the ultraviolet (UV) spectral region (from 200 nm and longer wavelengths) and the high energy side of the soft x-ray (sxr) region (below approximately 1 nanometer).

The Vacuum Ultra Violet region may be divided further:

  • Deep Ultra Violet (DUV): 200~120 nm
  • Extreme Ultra Violet (EUV or XUV): 50~10 nm
  • Soft X-Rays (SXR or XUV): 15~0.2 nm

These sub-divisions are physically meaningful too. The Deep UV is a region also accessible by dry gas purgeing rather than vacuum. It also ends at around Lyman-alpha and corresponds to the last possible transmittance of radiation through any window materials (fluoride glasses). The EUV and SXR are also notable for poor reflectivity of materials requiring optical designs have large deviation angles (grazing incidence angles).

comparison of wavelength, energy and frequency

VUV analysis requires ellimination of absorbing molecules from the optical path, e.g. High Vacuum (10E-5 Torr) or lower

Units in the Vacuum UV?
The energy E, the frequency n, and the wavelength λ of a photon are related by: E = hν = hc/Lambda
Electron Volt conversion: E (eV) = 1240/Lambda (nm)

Vacuum and vacuum units
The quality of vacuum is determined by the number of particles remaining in a system and average distance gas molecules travel before collisions with each other. Increasing this distance improves the quality of the vacuum.
Pressure is often measured in Torr or mBarr units.

Vacuum range

  • Atmospheric pressure is 750 Torr
  • Low vacuum 1 to 10-3 Torr
  • High vacuum (HV) 10-4 to 10-7 Torr
  • Ultrahigh vacuum (UHV) 10-9 Torr or lower

Vacuum Ultraviolet Spectroscopy Workstation

These spectroscopy workstations from McPherson are ideal for experiments in the vacuum and deep ultraviolet, potentially advancing quantum information science and engineering. Spectroscopy was central to the development of quantum mechanics, including discovery of blackbody radiation and Einstein’s photoelectric effect.

There are two experimental kits available, diagnostic and analytical. The diagnostic system equips the spectrometer with a sensitive CCD detector. Use it to measure spectral emission of laser interaction, high harmonic generation, plasma formation, luminescence, fluorescence and so on. The analytical system comes with a tunable deep UV light source, rather than the CCD detector, and is ready to explore one of the earliest predictions of quantum physics, Einstein’s photoelectric effect. The configuration is also good for measuring transmission, photocathode response, and reflection.

Key features of these workstations include a versatile and easy to use spectrometer, filters, open concept high-vacuum sample chamber with built-in optical breadboard, and easy to use vacuum pumping system. Systems may also have a deep UV light source and/or sensitive CCD detector. Students and experienced experimentalists will have more time to consider setups and interpret results when using these systems. In addition to optical characterization, perform basic physics experiments that explore the field of quantum behaviors useful for very practical technologies like quantum cryptography. More science means more engagement while also learning the fundamentals of laboratory setups.

laser interaction, high harmonic generation, plasma formation, luminescence, fluorescence

The McPherson spectroscopy workstations allow users to assemble a complete system and design interesting experiments. Very complex systems can be constructed by blending diagnostic and analytical system components or by adding parts of your own design. System flanges are compatible with a range of commercial and readily available parts. These systems may be optionally mounted on tables and shipped turnkey, ready for your experiments

Some 2020 events

Cancelled | Visit McPHERSON at booth #2715 at CLEO in San Jose (May 2020). CLEO is an international meeting to learn about innovative advances, research and new technologies from the laser science industry. With six days of technical sessions, special symposia, tutorials, short courses, professional advancement courses, business programming, workshops, exhibits and special events, CLEO highlights the latest research, applications and market-ready technologies in all areas of lasers and photonics. Cancelled

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