Title: Implementation and application of the peak scaling method for temperature measurement in the laser heated diamond anvil cell

Abstract

In this work, a new design for a double-sided high-pressure diamond anvil cell laser heating set-up is described. The prototype is deployed at beamline 12.2.2 of the Advanced Light Source at Lawrence Berkeley National Lab. Our compact design features shortened mechanical lever arms, which results in more stable imaging optics, and thus more user friendly and more reliable temperature measurements based on pyrometry. A modification of the peak scaling method was implemented for pyrometry, including an iterative method to determine the absolute peak temperature, thus allowing for quasi-real time temperature mapping of the actual hotspot within a laser-heated diamond anvil cell without any assumptions on shape, size, and symmetry of the hotspot and without any assumptions to the relationship between fitted temperature and peak temperature. This is important since we show that the relationship between peak temperature and temperature obtained by fitting the Planck function against the thermal emission spectrum averaged over the entire hotspot is not constant but depends on variable fitting parameters (in particular, the size and position of the fitting window). The accuracy of the method is confirmed through measuring melting points of metal wires at ambient pressure. Having absolute temperature maps in real time allows formore » more differentiated analyses of laser heating experiments. Finally, we present such an example of the pressure variations within a heated hotspot of AgI at a loaded base pressure of 3.8 GPa.« less

Authors:

Kunz, Martin  ^[1];

• Search DOE PAGES for author "Kunz, Martin"
• Search DOE PAGES for ORCID "0000-0001-9769-9900"

Yan, Jinyuan ^[2]; Cornell, Earl  ^[1];

• Search DOE PAGES for author "Cornell, Earl"
• Search DOE PAGES for ORCID "0000-0002-3503-5575"

Domning, Edward E. ^[1]; Yen, C. Ethan ^[3]; Doran, Andrew  ^[1];

• Search DOE PAGES for author "Doran, Andrew"
• Search DOE PAGES for ORCID "0000-0001-5158-4569"

Beavers, Christine M.  ^[2];

• Search DOE PAGES for author "Beavers, Christine M."
• Search DOE PAGES for ORCID "0000-0001-8653-5513"

Treger, Aaron ^[1]; Williams, Quentin ^[4]; MacDowell, Alastair A. ^[1]

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+ Show Author Affiliations

1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS)
2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS); Univ. of California, Santa Cruz, CA (United States). Earth and Planetary Sciences Department
3. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS); Berkeley High School, CA (United States); Univ. of California, Berkeley, CA (United States)
4. Univ. of California, Santa Cruz, CA (United States). Earth and Planetary Sciences Department

Publication Date:

Fri Aug 10 00:00:00 EDT 2018

Research Org.:

Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1482539

Alternate Identifier(s):

OSTI ID: 1463934

Grant/Contract Number:  

AC02-05CH11231; AC03-76SF00098

Resource Type:

Accepted Manuscript

Journal Name:

Review of Scientific Instruments

Additional Journal Information:

Journal Volume: 89; Journal Issue: 8; Journal ID: ISSN 0034-6748

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

42 ENGINEERING; 47 OTHER INSTRUMENTATION