EUV and Soft Xray Optics, Thin Films and Outer Space'

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EUV and Soft X-ray Optics, Thin Films and Outer
Space.

• Or what you can to do to help your local
  universe.
• David D. Allred, allred_at_byu.edu

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Preparing studying soft x-ray and EUV optical
elements

• Over the years we have participated in a number
  of space and planetary physics projects. These
  have allowed out students to have some amazing
  experiences. Projects include
• The Goldhelox project in the late 80s and early
  90s,
• Preparing the boron coating for the x-ray window
  on the chemical analysis snout of the Sojourner
  Rover. This was part of the 1997 Pathfinder
  Mission.
• The Image Mission (It sees some of the Van Allen
  radiation belts.) Launched March 25, 2000

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Sun in x ray and visible light
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Pathfinder Mission.

• Preparing the x-ray window on the chemical
  analysis snout of the Sojourner Rover.

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IMAGE Mission http//image.gsfc.nasa.gov/
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More projects

• Preparing a reflective surface for the neutral
  particle detector for the European Space agencies
  Mars Express. To be launched this year.
• Uranium and thorium oxide coatings for soft
  x-rays (150-400 eV) astronomy mirrors.
• Support for the Mars Society Desert Research
  Station near Hanksville. (A group of students and
  teachers in Utah are organizing to help.)
• I will focus on three of the projects (2,4 and
  6) in some detail.
• May mention
• 1. the tie in to the billion future of EUV
  optics in microelectronic device fabrication.
• 2. several opportunities for undergraduate
  students to do important research in our area

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Suns Magnetic Field
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Earths Magnetic Field
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Charged Particle in Magnetic Field
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EM Spectrum
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Divisions of EM Spectrum
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EUV Pictures
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EUV Movie of May 24, 2000 bright aurora and
plasmasphere tail
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EUV Movie of July 10, 2000
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Tail and Shoulder March 20,2001
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EUV Movie of June 24, 2000
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Mars Projects

• Preparing a reflective surface for the neutral
  particle detector for the European Space agencies
  Mars Express. To be launched this year.
• Support for the Mars Society Desert Research
  Station near Hanksville. (A group of students and
  teachers in Utah are organizing to help.)

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Start Surface for Neutral Particle Detector of
Mars Express Mission

• A near grazing incidence, antireflective coating
  for 121.6 nm- Spencer Olson, David Allred, Matt
  Squires, Douglas Markos, Cynthia Mills and R.
  Steven Turley- Brigham Young University, now at
  University of Michigan

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Planet Mars

• Third brightest object in the sky

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Fundamental Considerations

• Did Water Once Exist on Mars?

• Does Water Now Exist on Mars?

• Can Water Ever Exist on Mars?

Water is the most fundamental ingredients to
life. Therefore, if we, as humans, want to decide
whether life, our own or otherwise, can exist for
longer periods of time on Mars, we must
determine whether this basic necessity of life
can be found on Mars.
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Evidence
Existing evidence of water on Mars comes in the
form of visible riverbeds and river canyons.
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The question is then, if we can see that there is
a history of water on the surface of Mars, where
has all of this water gone? Several speculations
state that the water exists frozen beneath the
permafrost of the planets surface. Another
speculation is that water on Mars evaporated into
its atmosphere where it was then literally
blown away by the solar wind.
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Solar Wind
Solar wind is comprised of

• Neutral and Charged Particles Emitted From the
  Sun.

This stream of particles, or the solar wind, then

• Interacts With Atmospheres of Planets in Space.

Examples of this can be seen when a comets tail
is blown away from the direction of the sun.
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History of Mars Exploration
Mariner 4 - 1965
Mars Express - 2003
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Mars Express - 2003
In 2003, the European Space Association (ESA)
plans to launch a spacecraft to Mars that will
aid in determining the possibilities water.
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Energetic Neutral Particle Analyzer
One of several instruments on the ESA spacecraft,
the Energetic Neutral Particle Analyzer contains
a time-of-flight neutral particle detector (NPD).
The purpose of this instrument is to study the
effect of the solar wind on the atmosphere of
Mars. To do this, the NPD will measure the
momentum with which neutral particles in the
solar wind might bombard atmospheric particles,
thus showing how much the solar wind might erode
the atmosphere of Mars.
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Neutral Particle Detector (NPD)
When a particle enters into the NPD it reflects
off of a surface, labeled the Start Surface.
Upon impact on the Start Surface, an electron
(depicted as e-) is emitted from the surface and
attracted by an electric field to a detector
labeled the Start Detector, whereon a timer is
started. The neutral particle continues on after
reflection until it hits a detector labeled Stop
Detector, whereon the timer is stopped. The
speed of the particle is then calculated using
sixth grade physics speed distance / time.
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BYUs Participation
Energetic light, entering the orifice of the
instrument, may also reflect on the Start Surface
and create false stop signal in the Stop
Detector. In space, there is an abundant supply
of vacuum ultraviolet photons (especially 121.6
nm10.2 ev), which is energetic enough to cause
this effect. The XUV Research Group of BYU was
asked to provide a solution to this problem. The
remaining portion of this presentation will focus
on BYUs efforts in designing, this surface.
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Neutral Particle Detector (NPD)

• Criteria For NPD Start Surface

• UV Light Absorption

• Neutral Particle Reflectivity

• Electron Emissivity

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Absorption of Light withUltrathin Multilayers
A common method for controlling light is the use
of a thin film. A thin film is just what we
expect it to be it is a very thin layer of some
material. The principle for making an optic with
thin films lies in the fact that there can be
many interfaces where light can be reflected.
For the Start Surface, the superposition of these
many reflections must result in a minimum amount
of light leaving the surface. An example of a
thin film causing similar interference, with
which we are all familiar, is that of oil on a
puddle, on a rainy day.