NASA Technical Reports Server (NTRS) 20110003018: Wide-Range Neutron Detector for Space Nuclear Applications

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by  NASA Technical Reports Server (NTRS)

Physical Sciences
Cryogenic Caging for Science Instrumentation
NASA’s Jet Propulsion Laboratory, Pasadena, California
A method has been developed for In the example of a sensitive x–y seis- and their progeny, caging instrumenta-
caging science instrumentation to pro- mometer, the volume is filled with CO2 tion and avionics for penetrator mis-
tect from pyro-shock and EDL (entry, (at an elevated pressure), or other com- sions, and caging of electronics to sur-
descent, and landing) acceleration dam- patible liquid. Then the liquid is frozen vive launch shock.
age. Caging can be achieved by immers- and maintained at a temperature below This work was done by Konstantin Pena-
ing the instrument (or its critical parts) –80 °C for the duration of the flight. The nen and Talso C. Chui of Caltech for NASA’s
in a liquid and solidifying the liquid by solid is then allowed to sublime through Jet Propulsion Laboratory. Further informa-
cooling. After the launch shock and/or a valved port. Other uses include caging tion is contained in a TSP (see page 1).NPO-
after the payload has landed, the solid is of drag-free elements of LISA (laser in- 46930
heated up and evaporated. terferometer space antenna) spacecraft
Wide-Range Neutron Detector for Space Nuclear Applications
John H. Glenn Research Center, Cleveland, Ohio
A digital, wide-range, neutron detec- connected cabling, all of which are range of neutron fluxes ensures its de-
tion (WRND) system in a compact, VME adapted for the space environment from velopment is not necessarily linked with
form factor monitors neutron activity proven, terrestrial-based technology. any particular reactor type, and in no
within the core of a nuclear reactor WRND delivers logarithmic output sig- way limits future nuclear power imple-
across the reactor’s entire operating nals to a host system, proportional to mentation options, while still providing
range, from 1.0 n/cm2/s up to 1010 neutron flux and rate across the entire NASA with the needed functionality.
n/cm2/s. This allows for a reduction in operating range of the reactor. The elec- This work was done by John F. Merk of Au-
the complexity of space-based nuclear tronics module hardware and firmware rora Flight Sciences and Alberto Busto of
instrumentation systems, as a single in- are the basis of the innovation. Black River Technology for Glenn Research
strument can be used instead of requir- WRND is broadly compatible with Center.
ing different instrumentation for each many potential future applications (nu- Inquiries concerning rights for the commer-
of the operation ranges of the reactor clear power, nuclear propulsion, etc.). cial use of this invention should be addressed
(start-up, ramp-up, and nominal power). Nothing in the initial design assumes a to NASA Glenn Research Center, Innovative
This instrument consists of one or particular type of reactor, or whether it Partnerships Office, Attn: Steve Fedor, Mail
more fission chamber detectors, an inte- will be vehicle- or land-based. This inno- Stop 4–8, 21000 Brookpark Road, Cleve-
grated electronics module, and inter- vation’s ability to function over a wide land, Ohio 44135. LEW-18469-1
In Situ Guided Wave Structural Health Monitoring System
John H. Glenn Research Center, Cleveland, Ohio
Aircraft engine rotating equipment spect surface and subsurface cracks. applied to the surface of large curva-
operates at high temperatures and The sol-gel bismuth titanate-based sur- tures. It has minimal effect on airflow or
stresses. Noninvasive inspection of mi- face acoustic wave (SAW) sensor can rotating equipment imbalance, and pro-
crocracks in those components poses a generate efficient SAWs for crack in- vides good sensitivity.
challenge for nondestructive evalua- spection. The sensor is very thin (sub- This work was done by George Zhao of In-
tion. A low-cost, low-profile, high-tem- millimeter) and can generate surface telligent Automation, Inc. and Bernhard R.
perature ultrasonic guided wave sensor waves up to 540 °C. Finite element Tittmann of The Pennsylvania State Univer-
was developed that detects cracks in analysis of the SAW transducer design sity for Glenn Research Center.
situ. The transducer design provides was performed to predict the sensor be- Inquiries concerning rights for the commer-
nondestructive evaluation of structures havior, and experimental studies con- cial use of this invention should be addressed
and materials. firmed the results. to NASA Glenn Research Center, Innovative
A key feature of the sensor is that it The sensor can be implemented on Partnerships Office, Attn: Steve Fedor, Mail
withstands high temperatures and ex- structures of various shapes. With a Stop 4–8, 21000 Brookpark Road, Cleve-
cites strong surface wave energy to in- spray-coating process, the sensor can be land, Ohio 44135. Refer to LEW-18447-1.
NASA Tech Briefs, January 2011 27