TIMA

Introduction

The TESCAN Integrated Mineral Analyzer (TIMA) is a new SEM-based automated mineralogy solution for the mining and minerals processing industries. TIMA measures mineral abundance, size by size liberation, mineral association, grain size and PGM search automatically on multiple samples of grain mounts, thin sections or polished sections. Applications include ore characterization, process optimization, remediation and the search for precious metals and rare earths. Tescan’s unique technology is based on a completely integrated EDX system which performs full spectrum imaging at very fast scan speeds. Image analysis in TIMA is performed simultaneously with SEM backscatter electron images and a suite of x-ray images. The level of hardware integration of SEM and EDX allows unprecedented acquisition speeds for fully automated data collection, resulting in fast, accurate and reliable results.

TIMA SEM

The TESCAN TIMA is based either on a MIRA field emission scanning electron microscope, or a VEGA thermal emission scanning electron microscope equipped with either tungsten or LaB6 emitter featuring an ultra-fast YAG scintillator BSE detector, and a fast, computer controlled stage with a specially designed seven sample holder that includes a reference sample for automatic system calibration of both BSE and EDX detectors.

TIMA EDX

TIMA can be equipped with up to four silicon drift EDX detectors in analytical geometry to cover a maximum solid angle of x-ray collection for high throughput analysis. Total EDX input count-rates up to 1280kcps are possible. Collection of EDX data is synchronized with the scanning system and BSE signal acquisition using integrated hardware. This allows for scanning with one microsecond pixel dwell times while collecting all x-rays in perfect registration with the electron beam position.

Data Acquisition

The BSE and EDX detectors are automatically calibrated before starting an analysis. During the acquisition of data, real time thresholding of 16-bit BSE signal is applied and variable dwell EDX acquisition is enabled. The real acquisition time at each pixel is modulated by the BSE and EDX signal strength. This significantly accelerates the data acquisition process.

TIMA Software Capabilities

TIMA software is developed for BSE and EDS data collection, processing and analysis. It runs on the latest 64-bit edition of Windows allowing maximum computation performance. The software is released in two editions extendable by several software modules for each application:

• TIMA Online Acquisition Software – hardware control, automatic data acquisition and analysis
• TIMA Offline Analysis Software (option) – acquired data viewing and reanalyzing

TIMA Online Acquisition Software

• Automatic SEM and EDS data acquisition
• Automatic beam current optimization
• Automatic BSE signal calibration
• 16 bit BSE image processing
• Sample position and size definition
• Acquisition job settings

TIMA Offline Analysis

• Additional license for offline analysis
• Reanalysis of acquired data

General Software Features

Customizable mineral classification profiles

Export of tables to TXT, CSV or HTML

Export of images to BMP or PNG

Spectrum review, comparison with standard, MSA or PNG export

Panoramic sample preview

Modal Analysis Module

Mineral classification

Mineral mass evaluation

Element distribution maps

Point spectrum review and MSA export

Field review

Liberation Analysis Module (option)

Automatic particle detection

Automatic phase recognition and classification

Mineral association evaluation

Mineral liberation and locking classification

Element distribution maps

Particle and grain size distribution

Mineral mass evaluation

Particle texture mapping

Phase/grain spectrum review

Particle review

Electron Optics

VEGA – thermal emission gun
Improved column construction for higher stability and longer filament lifetime (up to 2500 hours)
Resolution:

SE 3.0 nm at 30kV
BSE 4.0 nm at 30kV

Accelerating voltage: 200V – 30kV
Beam current: 1pA to 2μA
Unique four lens Wide Field OpticsTM electron column


MIRA – Schottky field emission gun
Resolution:

SE 1.2 nm at 30kV
BSE 2.0 nm at 30kV

Accelerating voltage: 200V – 30kV
Beam current: 1pA to 200nA
Unique three lens Wide Field OpticsTM electron column

Chamber and Stage

Chamber LM
Chamber internal diameter: 230 mm
X × Y = 80 × 60 mm (without holder)
Z = 47 mm
Rotation: 360° continuous
Chamber suspension: pneumatic or optional active vibration isolation
Sample holder for 7 resin blocks (ø30mm) + position for BSE / EDX calibration standard

Detectors

• BSE – premium YAG scintillator BSE detector (manual or motorized retractable)
• SE – Everhart-Thornley
• Absorbed current meter
• Touch alarm
• IR chamber view camera

Other SEM Options upon Request

Low vacuum SEM mode

WDS (option – 1x WDS + 3x EDX detector)

EDS Detectors

Up to 4 x Silicon drift detector (SDD), Peltier cooled (no liquid nitrogen required)

Elevation angle: 35°

Detector area: 30 mm2 (or 10 mm2)

Maximum pulse load: 320 kcps (each EDS)

Energy resolution:

10 mm2 ≤ 129 eV (Mn Kα)
10 mm2 ≤145 eV (Mn Kα) at 1200 kcps (Au)
30 mm2 ≤ 132 eV (Mn Kα)
30 mm2 ≤155 eV (Mn Kα) at 1200 kcps (Au)