Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Neutron detector under development to monitor spacecraft radiation

12.11.2003


It’s no secret that radiation is a great danger to astronauts. Most of the research to date concerns the effects of galactic cosmic rays, but what happens to those particles when they pass into a spacecraft?



A device currently being tested will reveal what kind of neutron energy spectrum astronauts are exposed to from neutrons inside a spacecraft, alerting the occupants when dangerous levels occur.

“When spacecraft travel through a variety of primary high-energy cosmic rays, large vehicles absorb those rays and convert them into neutrons,” said Dr. Richard Maurer, a researcher on the National Space Biomedical Research Institute’s (NSBRI) technology development team. “The spacecraft’s thick structure, in a sense, multiplies the primary particles so that there are more neutrons trapped inside a craft than the original number of cosmic rays that created them.”


The project’s goal is to develop a device that is lightweight and portable that could be transferred from the transport craft to a habitation facility or wherever it is needed. Currently, there is no compact, portable, real-time neutron detector instrument available for use inside a spacecraft or on planetary surfaces.

“These types of measurements would be crucial for exploration missions outside Earth’s orbit where there is no protection from Earth’s magnetic field,” Maurer said.

Primary radiation particles, ranging from infrared photons to galactic cosmic rays, have been measured for years, but neutrons have not been measured adequately particularly at high energy. Instruments used to measure radiation often miss the secondary neutrons, which astronauts are also exposed to. Maurer said the estimates of the radiation that astronauts receive from neutrons account for about one-third of the actual total dose.

“Since neutrons do not carry any electrical charge, they are both harder to detect and can penetrate more deeply into a space traveler’s body producing an increased risk of cancer, DNA damage and central nervous system damage,” said Maurer, principal staff member at The Johns Hopkins University Applied Physics Laboratory, Laurel, Md., and principal investigator on the project.

To make the measurements, the device converts some of the neutron’s energy into light or a charge by making it interact with a detector. This process does not capture every neutron or all the energy of the neutrons detected, so a response function must be established to calibrate the percentage of particles detected and their energies, which are determined by analyzing the amount of light output or charge in the detectors.

The device, consisting of several detector systems that measure both low- and high-energy neutrons, has been through ground-based testing and calibration using radioactive sources and accelerator facilities.

Besides ground-based and aircraft flight tests, Maurer’s real-time neutron spectrometer recently executed a successful scientific experiment on a balloon flight at an altitude of 85,000 feet. The small amount of atmosphere remaining at this altitude on Earth is similar to that on the surface of Mars, and the high energy neutron spectra should be the same. Approximately 750,000 neutrons were detected by two detector systems over a period of 22 hours, and the data are being analyzed.

“An interesting thing about neutrons is that they are not deterred by the typical heavy materials that shield astronauts from charged particles, but rather by things that contain hydrogen, like water,” Maurer said. “Future shielding against neutrons could include water, or possibly a room inside an outpost’s water supply.”

Damage from neutrons can also be a problem for nuclear workers exposed to neutrons, people living at high elevations, and pilots flying at high altitudes on long-haul schedules or on flights over the poles, where the Earth’s magnetic field is weak and cosmic rays can readily penetrate.

“When traveling outside of the Earth’s atmosphere and its magnetic field, radiation doses to humans increase,” Maurer explained. “Recent measurements from the Mars Odyssey mission show that the total radiation dose is about three times that on the more protected International Space Station.”



The NSBRI, funded by NASA, is a consortium of institutions studying the health risks related to long-duration space flight. The Institute’s research and education projects take place at more than 70 institutions across the United States.

Liesl Owens | NSBRI

More articles from Process Engineering:

nachricht Etching Microstructures with Lasers
25.10.2016 | Fraunhofer-Institut für Lasertechnik ILT

nachricht Applying electron beams to 3-D objects
23.09.2016 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>