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

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, [email protected]
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:
1. The Goldhelox project in the late 80’s and early 90’s,
2. 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.
3. The Image Mission: (It sees some of the Van Allen radiation belts.)
Launched March 25, 2000
Sun in x ray and visible light
http://solar.physics.montana.edu/Y
POP/FilmFestival/index.html
Pathfinder Mission.
• Preparing the x-ray window on the chemical
analysis snout of the Sojourner Rover.
IMAGE Mission http://image.gsfc.nasa.gov/
More projects
4.
Preparing a reflective surface for the neutral particle
detector for the European Space agencies Mars
Express. To be launched this year.
5. Uranium and thorium oxide coatings for soft x-rays
(150-400 eV) astronomy mirrors.
6. 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
Sun’s Magnetic Field
Earth’s Magnetic Field
Charged Particle in Magnetic Field
EM Spectrum
Divisions of EM Spectrum
EUV Pictures
EUV Movie of May 24, 2000
bright aurora and plasmasphere tail
EUV Movie of July 10, 2000
Tail and Shoulder: March 20,2001
EUV Movie of June 24, 2000
Mars Projects
4. Preparing a reflective surface for the
neutral particle detector for the European
Space agencies Mars Express. To be
launched this year.
5.
6. Support for the Mars Society Desert
Research Station near Hanksville. (A
group of students and teachers in Utah
are organizing to help.)
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
Planet Mars
• Third brightest object in the sky
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.
Evidence:
Riverbeds
Existing evidence of water on Mars
comes in the form of visible riverbeds
and river canyons.
River canyons
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.
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 comet’s tail is blown
away from the direction of the sun.
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.
Energetic Neutral Particle
Analyzer
One of several instruments on the
ESA spacecraft, the Energetic Neutral
Particle Analyzer contains a time-offlight 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.
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.
BYU’s 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
nm=10.2 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 BYU’s efforts in
designing, this surface.
Absorption of Light with
Ultrathin 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.