Tech_Specs_Geotek_XRF-II_1.pdf

Technical Specifications for Geotek XRF sensor

1. Overview This document specifies the technical, performance, and integration requirements for acquiring a micro‑XRF sensor for installation on the GMEG Science Center’s Geotek MSCL‑XZ‑II Joint Hyperspectral Analyzer Work Station (JHAWS). The system must provide non‑destructive, rapid, and spatially precise geochemical analyses of soft‑sediment and hard‑rock core materials while maintaining full compatibility with the existing JHAWS platform. Requirements outlined here define the minimum acceptable capabilities for X‑ray source performance, detector characteristics, sample‑cell atmosphere, precision stage movement, software functionality, and infrastructure needs to ensure seamless integration, reliable operation, and high‑quality geochemical mapping across split‑core surfaces.

2. General requirements

• Allow non-destructive rapid geochemical analysis of soft sediment and hard-rock drill core samples

• Be compatible with the pre-existing GMEG Science Center's Geotek MSCL-XZ-II

Joint Hyperspectral Analyzer Work Station (JHAWS) core logging system

• Integrate XRF sensor with precision stage movements to allow geochemical element mapping across split core surfaces at X-Y spatial resolutions better than 1 cm spot-sizes

• Element detection range: Al to U

3. X‑Ray Source & Optics

• X‑ray source voltage range: 4 kV to 50 kV

• 15 W sealed Rh or Mo target X‑ray tube

• Source–sample–detector geometry to maximize signal-to-noise ratios (SNR)

• Changeable X-ray filter assembly to improve detection of key elements (e.g., Ti filter to enhance the Mn K-alpha line)

• Easy‑to‑replace X-ray transparent window

• Large‑area SDD detector to maximize SNR

• Spectral resolution: ≥133 eV at Mn Kα

4. Measurement cell & atmosphere

• Helium‑flushed measurement cell

• Ability to quantify low‑energy elements accurately (Na, Mg, Si, Al, etc.)

• He attachment compatible with GMEG Science Center's JHAWS instrument

5. Precision stage movement

• Down‑core collimation: at least 0.5 mm

• Cross‑core collimation: at least 5 mm

6. Infrastructure requirements

• No chiller required

• Standard laboratory power compatible with existing JHAWS system (US 110V)

7. Software & data processing

• Full control of X‑ray settings and filter positions

• Spectral analysis and fitting

• Can generate maps of downcore element concentrations from core sample surfaces

• Fundamental parameters calibration

• Exportable XRF spectra

• Integrates with pre-existing Geotek software that controls JHAWS

8. Delivery and training

• Compatible with JHAWS/MSCL‑XZ hyperspectral core logging system

• Fully on‑site upgrade/installation by Geotek technicians into JHAWS system at

Moffett Field, Ca

• No requirement to send JHAWS instrument back to manufacturer

• Installation visit also includes training of USGS personnel on instrument & software

10. Performance Requirements

• The XRF system must deliver stable, repeatable measurements across the full elemental detection range (Al–U) with minimal drift over extended scanning periods.

• System must maintain spectral resolution of ≥133 eV at Mn Kα under normal laboratory operating conditions.

• Precision stage movement must support down‑core spatial resolutions of at least 0.5 mm and cross‑core resolutions of at least 5 mm without loss of alignment.

• Measurement cell must sustain consistent helium atmosphere sufficient for accurate low‑energy element quantification.

• Software must support automated scan sequencing, user‑defined scan modes, and integration with JHAWS data workflows.

• X‑ray tube and detector must maintain performance within manufacturer tolerances for continuous operation typical of long core‑logging sessions.

11. Minimum Acceptable Specifications

• Elemental Range: Al to U

• X‑ray Source: 4–50 kV, 15 W sealed Rh or Mo tube

• Detector: Large‑area SDD detector with ≥133 eV resolution at Mn Kα

• Collimation: ≥0.5 mm down‑core; ≥5 mm cross‑core

• Atmosphere: Helium‑flushed measurement cell for low‑energy element detection

• Software: Full control of X‑ray settings, filter selection, spectral fitting, and elemental mapping

• Integration: Full mechanical and software compatibility with existing Geotek

MSCL‑XZ‑II (JHAWS) system

• Power & Cooling: Standard laboratory power; no external chiller required

• Installation: On‑site integration by qualified Geotek technicians