Planetary Science Institute Lab Annual Report for 2017 prepared by Neil Pearson

Summary

In October of 2017 Neil Pearson was hired as the Lab Technician for the Planetary Science Institute (PSI), with the primary purpose to run and upkeep equipment that was purchased by PSI and its associated scientists. This report will cover activities between October, November and December of 2017.

The spectroscopy lab currently has three main instruments in house and a fourth that is with Dr. Eldar Noe Dobrea at NASA Ames. The three instruments currently at PSI are the Andor-McPherson Vacuum (VUV) , the Ocean Ultraviolet to Visible spectrometer, and the Analytical Spectral Devices (ASD) Fieldspec 3 visible to short wave spectrometer. Dr. Eldar Noe Dobrea has in his possession an Olympus Terra X-ray diffractomeer and X-ray fluoresence spectrometer. Additionaly, the lab contains and high vacuum chamber for measuring samples in space like conditions.

Efforts since October have focused on tuning and calibrating instruments, and preparing the laboratory for measuring samples for the Toolbox for Research and Exploration project headed by PSI’s Dr. Amanda Hendrix, and investigating reflectance standards for the vacuum-UV

Currently two abstracts were submitted to the 2018 Lunar and Planetary Science Conference that will use spectra taken at the PSI spectroscopy lab.

Laboratory Instruments

The Andor-McPherson VUV spectrometer is the most unique instrument at the PSI spectroscopy lab. This instrument combines a Andor Solis cooled silicon detector array with a McPherson Inc. Monochrometer and 300 line/mm grating. The VUV spectrometer measures reflectance of minerals samples in the VUV down to ~0.115μm and in its normal operating mode goes to 0.4μm with a spectral resolution of 8nm. This range can be extended to 0.6μm if desired and resolution can be increased to 2-3nm if the grating is switched to a 1200 line/mm grating. This spectrometer also a filter wheel that contains order sorting and band pass filters used for calibration.

The Ocean Optics UV-VIS spectrometer has a spectral range of 0.2μm-0.88μm and 2nm resolution throughout this range. It can be operated with or without a 600mil fiber optic cable. It is capable of taking spectra in the sample chamber through a sapphire glass window and is small and portable enough to be taken into the field if needed.

The Analytical Spectral Devices Fieldspec 3 (ASD) has a spectral range of 0.35μm to 2.5μm with a spectral resolution of 3nm in from 0.35 to 1.0μm and 10nm from 1.0μm to 2.5μm. This instrument also has a fiber optic cable that will take spectra through the sapphire window of the vacuum chamber. For field spectroscopy the ASD can use the fiber optic and or a hand held light and fiber optic holder that limits the spot size to ~1in in diameter. Additionally there is a back pack that carries the ASD in the field and the requisite equipment for it.

The Olympus Terra XRD/XRF uses a copper source and has a range of 5-55° 2Θ. The instrument can be brought into the field and minimal sample preparation is needed. Currently efforts to ensure the PSI laboratory is in compliance of Arizona radiation safety standards so the instrument can be brought to the PSI laboratory.

Additional support equipment in the lab includes: 1. A combination safe to secure potentially valuable samples 2. An analytical balance accurate to 0.1mg with a range up to 220g 3. A set of sieves ranging from 1mm to 10μm 4. A high vacuum chamber capable of reaching 10-6torr in pressure

Projects

Two primary projects have are currently the focus of the PSI laboratory, the Toolbox for Research and Exploration SSERVI (TREX) project, and a more informal project of looking at different materials for use as a reference in the VUV portion of the spectrum. The laboratory will start measuring small grained samples for the TREX project in late January to early February, and we have begun discussing how to transport samples prepared in an inert environment between laboratories for weathering studies. The VUV standards project has purchased several metals and ground them to different finishes and is ongoing. Both of these projects have involved tuning and calibrating laboratory equipment.

Papers

Two abstracts that will contain data taken by the PSI laboratory have been submitted to the 2018 LPSC.

Toolbox For Research and Exploration (TREX): The Fine-Particle Spectral Library. Melissa. D. Lane , J. P. Allain , K. S. Cahill , R. N. Clark , E. A. Cloutis , M. D. Dyar , J. Helbert , A. R.Hendrix 3 , G. Holsclaw 7 , M. Osterloo 7 , N. Pearson 3 , D. W. Savin 8 , and the TREX team. LPSC, 2018.

Toolbox for Research and Exploration (TREX): Investigations of Fine Grained Materials on Small Bodies. Deborah. L. Domingue, J.-P. Allain, M. Banks, R. Christoffersen, M. Cintala, R. Clark, E. Cloutis, A. Graps, A. R. Hendrix, H. Hsieh, M. D. Lane, S. Lederer , J.-Y. Li , E. Noe Dobre, T. Prettyman 1 , D. W. Savin 7 , N. Schorghofer 1 , K. Stockstill-Cahill 1 , F. Vilas 1 , and the TREX team. LPSC, 2018 The PSI Vacuum Chamber setup January 2018 with .