A versatile, novel, multifunctional hybrid structural composite of a high-hydrogen epoxy matrix (UN-10) coupled with boron and carbon fibers (IM-7) has been developed. Prototype laminates of 18×18 in. (≈46×46 cm), with the nominal areal density of 0.35 g/cm2, were fabricated in this effort. The hydrogen atoms in the epoxy will provide shielding strength against high-energy protons, electrons, and heavy ionic species, while the boron fibers that have a high neutron cross-section will help shield against neutrons and reduce the buildup of high-energy photons from secondary reactions. The carbon fibers will provide improved mechanical strength.

Fortifying Computer Chips for Space Travel

TBMG-2318810/16/2015

Space is cold, dark, and lonely. Deadly, too, if any one of a million things goes wrong on your spaceship. It’s certainly no place for a computer chip to fail, which can happen due to the abundance of radiation bombarding a craft. Worse, ever-shrinking components on microprocessors make computers more prone to damage from high-energy radiation like protons from the sun or cosmic rays from beyond our galaxy. It’s a good thing, then, that engineers know how to make a spaceship’s microprocessors more robust. To start, they hit them with high-energy ions from particle accelerators here on Earth. It’s a radiation- testing process that finds a chip’s weak spots, highlighting when, where, and how engineers need to make the microprocessor tougher.

Nanocomposites for Radiation Shielding

TBMG-22543

8/1/2015

Currently, lead and lead-based materials are used to fabricate shields not only for X-rays, but also for other types of radiation. With the growing environmental concern about the toxicity of lead, and the high costs associated with transporting heavy lead-based shields in spacecraft, alternatives are needed for fabricating X-ray shields that are less toxic and lighter.

Validation of an “Intelligent Mouthguard” Single Event Head Impact Dosimeter

2014-22-000111/10/2014

Dating to Colonel John Paul Stapp MD in 1975, scientists have desired to measure live human head impacts with accuracy and precision. But no instrument exists to accurately and precisely quantify single head impact events. Our goal is to develop a practical single event head impact dosimeter known as “Intelligent Mouthguard” and quantify its performance on the benchtop, in vitro and in vivo. In the Intelligent Mouthguard hardware, limited gyroscope bandwidth requires an algorithm-based correction as a function of impact duration. After we apply gyroscope correction algorithm, Intelligent Mouthguard results at time of CG linear acceleration peak correlate to the Reference Hybrid III within our tested range of pulse durations and impact acceleration profiles in American football and Boxing in vitro tests: American football, IMG=1.00REF-1.1g, R2=0.99; maximum time of peak XYZ component imprecision 3.6g and 370rad/s2; maximum time of peak azimuth and elevation imprecision 4.8° and 2.9°; maximum average XYZ component temporal imprecision 3.3g and 390rad/s2. Boxing, IMG=1.00REF-0.9g, R2=0.99, R2=0.98; maximum time of peak XYZ component imprecision 3.9g and 390rad/s2, maximum time of peak azimuth and elevation imprecision 2.9° and 2.1°; average XYZ component temporal imprecision 4.0g and 440rad/s2. In vivo Intelligent Mouthguard true positive head impacts from American football players and amateur boxers have temporal characteristics (first harmonic frequency from 35Hz to 79Hz) within our tested benchtop (first harmonic frequency <180Hz) and in vitro (first harmonic frequency <100Hz) ranges. Our conclusions apply only to situations where the rigid body assumption is valid, sensor-skull coupling is maintained and the ranges of tested parameters and harmonics fall within the boundaries of harmonics validated in vitro. For these situations, Intelligent Mouthguard qualifies as a single event dosimeter in American football and Boxing.

Bartsch, Adam, Samorezov, Sergey, Benzel, Edward, Miele, Vincent, Brett, Daniel

Determining Radiation Shielding Capability of the Earth’s Atmosphere from FAA Radiation Data

TBMG-20571

9/1/2014

The FAA, using its CARI-6 program, provides galactic cosmic radiation dosage rates for any location on the Earth from ground up to 60,000 ft (≈18,300 m). One way to protect astronauts from galactic cosmic radiation (GCR) on a Mars mission is to use material shielding. However, current radiation shielding code does not model shields thicker than about 100 to 200 gm/cm2, and it has been shown that this shield thickness is insufficient to provide protection for a trip to Mars. There is effort underway to extend the code to thicker shields, but there is a lack of experimental data to use to verify the code. The atmosphere represents a very thick and effective radiation shield, and that atmospheric radiation data might be used as a source of verification data.