MC-ICPMS_Requirements.pdf

Large Geometry Multiple Collector Inductively Coupled Mass Spectrometer -Requirements

The following represent a minimum list of requirements for the large dispersion high-resolution multiple collector inductively coupled mass spectrometer:

• Mass Analyzer:

o Double focusing large (minimum of 750 mm) radius magnet mass analyzer with aptly sized ESA o High precision 24-bit laminated magnet, magnet slave and multi-Hall probe Control unit o Zoom/Variable dispersion ion optics

• Transfer Optics:

o Extraction Lens system o Transfer Lens system with adjustable slit mechanism o Selectable X,Y alpha slit mechanism

• Source Collision Cell:

o Dual path optics for operating the instrument in either high energy mode (Standard MC- ICP-MS mode) or low energy mode (Collision/Reaction cell mode)

• Collector System:

o 16 state-of-the-art Faraday cup detectors each with independently adjustable slit resolution and associated precision preamplifiers o Five state-of-the-art ion-counting electron multipliers o Ion counting deflection optics o Single deceleration filter for improved abundance sensitivity

• Plasma Source:

o Argon plasma torch system with active matching network o 27MHz 2.0kW RF supply o Peltier cooled spray chamber system o Peristaltic pump

• Vacuum System:

o 3 x Edwards 300l/s turbo pumps and controllers o 2 x Edwards 80l/s turbo pumps and controllers o E2M80, RV5 and RV3 Edwards rotary pumps o 1 x 40l/s and 5 x 160l/s Gamma ion pumps and 2 x ion pump supplies o Associated vacuum gauges o 2 x UHV Gate valves

• Electronics:

o Programmable voltage and magnet supplies o 16 Channel Faraday Preamplifier unit o 16 Channel programmable DVM o Programmable System Control unit o Ion counting voltage and preamp/discriminator supplies o Gas Panel providing 5 x mass flow-controlled gas supplies

• Computer System:

o Intel i5 PC, 8GB RAM, 500GB hard drive, DVD +/- RW drive, 23” TFT flat screen monitor, Monochrome Laser printer, Windows operating system & MS Office, Software-PC based multitasking suite

• Accessories:

o Autosampler—CETAC ASX-112FR o Desolvation System—CETAC Aridus 3 Desolvation System, Fitted with 1 x 100 μl glass nebulizer o Switchable preamplifiers—Inclusion of a switchable preamp within the 16-channel preamplifier bin capable of switching between 2 on-board resistors of either 1010, 1011 or 1012 ohm resistors o Dry Pump Upgrade—Edwards nXDS10i for turbo backing and Edwards iXL120 plasma interface; Chillers for turbo and plasma interface pumps

• Performance requirements include:

o Mass stability better than ±25 ppm/hr using 238U peak o High resolution of >30,000 edge resolving power (5, 95%) at >1% transmission while maintaining peak flats.

o Peak flat parallelism <1 in 104 over ±250 ppm for both “low” resolution (1000-2000RP) and “high” resolution (3000-5000RP) o Abundance sensitivity at low resolution measured at mass 237 with respect to mass 238 with an uranium ion beam of at least 4x10-11 amps:

without filter <1 ppm with filter <100 ppb o UHV standards as to permit the instrument to operate in the low 10-9 mbar range even when the source is at atmospheric pressure.

o Isotope ratio performance (All errors below are 1-sigma (1σ): internal precision = 1RSE;

external precision = 1RSD for Sr and Nd, external precision = 1SD for Mg):

Magnesium: 26Mg/24Mg internal ≤ 0.002% (20 ppm), external ≤ 0.004% (40 ppm), Sample/standard bracketing.

Strontium: 87Sr/86Sr internal ≤ 0.001% (10 ppm), external ≤ 0.0020% (20 ppm), Internal normalization to 86Sr/88Sr = 0.1194.

Neodymium: 142Nd/144Nd internal ≤ 0.001% (10 ppm), external ≤ 0.002% (20 ppm); 143Nd/144Nd internal ≤ 0.001% (10 ppm), external ≤ 0.0015% (15 ppm);

145Nd/144Nd internal ≤ 0.001% (10 ppm), external ≤ 0.001% (10 ppm), Internal normalization to 146Nd/144Nd = 0.7219.

• Ability to communicate and couple with femtosecond laser ablation systems