Microprobe Instrument Specification

for

UCB

Department of Geology

August 1994

Table of Contents

A. General Requirements
B. Inclusion of Vendor's Technical Proposal into this Specification
C. Preliminary Testing by Vendor Prior to Shipping
D. Installation and Acceptance Testing
E. On Site Training
F. Documentation
G. Technical Specifications and Requirements

1. Electron gun
2. Electron column
3. Wavelength spectrometers
4. Secondary and backscattered electron digital imaging system
5. Light-optical image system
6. Automatic vacuum control system
7. Specimen chamber with specimen exchange system
8. Sample stage/motor system
9. Instrument control and data interface

H. Quantitative acceptance tests to be performed by UCB
I. Additional Equipment Options
J. Miscellaneous

 

A. General Requirements

The vendor shall furnish all facilities, labor, and materials to provide goods and services in accordance with the terms and conditions described in this specification for both the hardware and software. The Vendor shall maintain an inventory of spare and repair parts and such tools and instruments as necessary to properly and efficiently maintain the equipment for the life of the microprobe itself. Spare parts and consumables must be obtainable within a maximum of 20 working days after a purchase order number is received by the Vendor. The specifications listed in this document are the minimum requirements for the Department of Geology and Geophysics microprobe.

Please provide a detailed competitive price quotation for each major component, device or feature. Please quote each price and the system total on a duty free basis (however please include California sales tax @8.25 % and inland transportation costs) as we will be applying for a customs duty exemption. The prices quoted should reflect any educational discounts that can be applied to a non-profit educational organization purchase.

Please include in the quotation any additional equipment or software and pricing that will be required to efficiently operate all instrument features specified in this document if they are not standard equipment or not explicitly stated in the specifications.

A catalog and current price list of all spare parts and assemblies shall be provided by the Vendor with the instrument.

B. Inclusion of Vendor's Technical Proposal into this Specification

The Vendor's technical proposal entitled, [ ] dated [ ], is incorporated by reference and made a part of this contract. In the event of any inconsistency between the provisions of this contract and the Vendor's technical proposal, the contract provisions in this document take precedence.

C. Preliminary Testing by Vendor Prior to Shipping

Documentation of performance in accordance with following preliminary specifications shall be provided by the Vendor before shipping the instrument. The seller shall provide the necessary personnel, equipment and facilities to conduct these same acceptance tests and the other specifications described in section G. below entitled "Technical Specifications" on the installed instrument, unless this document specifically states that UCB (University of California at Berkeley) shall provide the items required.

Preliminary Performance Specifications to be Received by UCB Prior to Instrument Shipping :

- Electron gun specifications 1a
- Electron column specifications 2b, 2c, 2j
- Wavelength spectrometer specifications 3a, 3c, 3g, 3i
- Secondary and backscattered specifications 4a, 4c
- Light optical specifications 5d, 5e
- Vacuum specifications 6a, 6b, 6c
- Specimen chamber specifications 7b, 7c
- Stage specifications 8b, 8c, 8d

D. Installation and Acceptance Testing

Acceptance of the instrument shall be based upon completion of installation and after testing of instrument hardware performance on site at UCB, McCone hall, Berkeley, CA by personnel selected by UCB.

The instrument shall meet ALL specifications described in this specification and the Vendors included proposal (with appropriate calculated scale factors at UCB's normal operating condition of 15 KeV). The instrument shall meet the specifications before acceptance and again 1 year after acceptance.

The acceptance tests shall be performed on samples provided by the Department of Geology at UCB, including thin sections, polished mounts of minerals and oxides and metal elements and alloys. Final payment will be made after all acceptance tests have been completed and the instrument meets all specifications in this document.

Although the instrument will be bought without the Vendor's standard computer system, it will still be necessary for the Vendor to install the standard computer system for the running of acceptance tests, to be conducted on site by UCB and supply all necessary documentation for interfacing to the instrument microprocessor(s). After running the acceptance tests and the instrument is accepted, the Vendor will remove the Vendor's standard computer system and software at no additional cost to UCB.

The Vendor shall provide all parts, materials, labor, and transportation required to perform preventive and remedial maintenance on the instrument during the installation and acceptance testing period. The maintenance services shall also be performed in accordance with the terms, conditions, and statement of work set forth herein. The Vendor's warranty shall not begin until the instrument has passed all acceptance tests and meets all technical specifications described in this document. Any consumables (filaments, light bulbs, etc.) required to run the instrument during the acceptance testing shall be supplied by the Vendor at no extra cost to UCB.

Preventive maintenance shall include, but not be limited to, cleaning, adjusting, lubricating, inspecting, and testing procedures to keep the equipment in good operating condition, preclude equipment failures to the greatest extent possible, and extend useful equipment life. It includes running of all diagnostics, and repair and replacement of all defective parts.

Remedial Maintenance shall include replacement of parts that do not meet the specifications or requirements described in this document. This includes all transportation, labor and parts required for the parts replacement or upgrade.

All parts, materials, and components, including expendable items, shall be replaced when necessary during the installation and acceptance testing period at no additional cost to the University. Replaced parts shall become the property of the Vendor.

The work to be performed shall be in accordance with the original equipment Vendor's specifications and recommendations. All services are to be performed by competent personnel, experienced and highly qualified to provide required services in accordance with the best commercial practices, without unnecessary delays or interference with University functions.

E. On Site Training

Training for one designated personnel for the instrument in the operation of all hardware and software shall be provided at destination. Training shall be approximately two weeks in length, and be conducted during regular business hours Monday through Friday.

F. Documentation

Documentation manuals shall be provided for the instrument, that clearly and completely describe hardware and software operation, troubleshooting, and maintenance of all components of the microprobe. All manuals for Vendor supplied third-party items shall be provided.

General interconnect and wiring schematics in English and spectrometer, sample stage and sample holder(s) mechanical drawings with dimensions and tolerances shall be provided by the Vendor. Detailed instrument schematics shall be available from the vendor in the event that UCB might make future modifications.

G. Technical Specifications and Requirements

The Department of Geology at the University of California requires a state-of-the-art, fully automated electron microprobe to conduct its research programs. This microprobe shall be able to both qualitatively and quantitatively analyze and image all elements from Be to U and must meet the following additional requirements :

1. Electron gun :

a) current stability 0.05 % or less per hour (+/- 0.025 %) and 0.3 % or less per 12 hours (+/- 0.15 %) and 0.5 % or less in 24 hours (+/- 0.25 %) as measured at 15 KeV and 30 nA while repeatedly inserting the faraday cup once per minute

b) gun to be automatically biased as accelerating voltage is changed

c) current range from at least 1 nanoamps to 1000 nanoamps with 6 % or less (+/- 3 %) absolute accuracy

d) typical operating life of the tungsten filaments shall average 1000 hours or better at normal filament current, emission and saturation conditions (0.5 micron beam diameter and 50 nA beam current at 15 KeV)

2. Electron column :

a) accelerating voltages from 1 KeV to as much as 30 KeV in at least 1 KeV steps

b) absolute accuracy of accelerating voltage at 15 KeV must be less than 0.6 % (+/- 0.3%) from the nominal accelerating voltage or within 50 volts of 15 KeV as determined using the Duane-Hunt limit test or other equipment supplied by UCB or LBL (this may require transportation, approx. 1/2 mile, of HV gun supply to LBL for calibration testing overnight)

c) high voltage instability must be no more than +/- 0.005 % per hour (+/- 50 ppm) as determined by equipment supplied by UCB or LBL (see 2b)

d) beam diameter shall be less than 0.5 microns at 15 KeV and 50 nA defined as 99 % of primary electrons as measured across an synthetic interface and measured using a signal from the SE detector

e) stray beam measured using a 100u W or Mo aperture target in a Ti target block to produce a W or Mo and Ti k-ratios (both EDS and WDS) less than 0.0001 using a 100 nA beam and at operating voltages from 5 KeV to 30 KeV

f) beam diameter shall be adjustable from focus to 100 microns and shall focus/defocus in a symmetrical manner when the objective lens current is varied

g) beam current shall not change more than 0.5 % (+/- 0.25 %) and the SE image shall not vibrate or shift more than +/- 1 micron while the spectrometers are driven over their full range when a point of interest is viewed under SE at 10,000X.

h) beam focus and position shall not visibly move during condenser lens adjustment as viewed at 300-400X on a fluorescent sample

i) final apertures must be externally selectable and have external X-Y adjustments

j) the beam monitoring aperture current variation shall be less than 0.2 % (+/- 0.1 %) when measured on both a carbon sample and on a Fe sample at both 10 KeV and 25 KeV

k) the carbon contamination rate shall be less than 0.16% C/minute on a polished Cu sample for 30 minutes at 20 KeV and 100 nA with a 10 micron focused beam without the use of a cold finger or gas jet anti-contamination device; and the carbon contamination rate shall be less than 0.01% C/minute on a polished Cu sample for 30 minutes at 20 KeV and 100 nA with a 10 micron focused beam with the use of a cold finger or gas jet anti-contamination device

l) absolute accuracy of all magnification readouts or displays at 5, 10, 15, 20, 25 and 30 KeV must be less than 5 % (+/- 2.5 %) at 100x, 500x, 1000x, 5000x, 10,000x, 20,000x and 40,000x using NBS/NIST standard 484a or other appropriate magnification standards

m) there shall be no window, or written documentation must be provided demonstrating the superior performance of the microprobe with a window between the spectrometer housings and the column vacuum chambers; if column windows are required, the vendor shall provide two spare windows for each spectrometer

n) the instrument shall be provided with a manual aperture turret or wheel to control the x-ray intensity input from the probe to an EDS detector system. In addition, an external beam control option is to be provided by the Vendor, for use by the third party EDS digital beam control hardware. All mechanical flanges and/or adapters required for installation of the third party EDS hardware is to be provided by the Vendor.

The Vendor shall provide detailed mechanical drawings showing the EDS mounting system, aperture and port configuration for possible collimating apertures to be manufactured and installed by UCB.

 

3. Wavelength spectrometers :

a) five (5) vertical mounted (optical encoding preferred but not required) wavelength dispersive X-ray spectrometers using xenon sealed (XePC) or P-10 flow (GFPC) at 1.0 atmospheres regulated detectors with (externally adjustable detector slits from 300 - 3000 microns, if they are standard equipment, and) scattered electron filter magnets for the flow proportional detectors. The following spectrometer configuration is desired :

- #1 PET/TAP GFPC w/ 20 - 30mg/cm2 (0.2 - 0.3m) polypropylene window

- #2 PET/LiF XePC or 3 atm P-10 GFPC w/ 1.0m Be window

- #3 TAP/PET (or ADP instead of PET if required for Al ka analysis) GFPC w/ 20 - 30mg/cm2 (0.2 - 0.3m) polypropylene window

- #4 PET/LiF XePC or 3 atm P-10 GFPC w/ 1.0m Be window

- #5 TAP/PET/W/Si LDE (60A 2d)/empty GFPC w/ 20 - 30mg/cm2 (0.2 - 0.3m) polypropylene window (4 crystal spectrometer)

- the manufacturer shall supply an additional 4 blank crystal mounting backs of standard configuration, suitable for use by UCB to mount experimental LDE analyzers

b) high speed (DC servo motors preferred but not required) for low vibration motion (limit to limit travel in 30 seconds or less, although 20 seconds or less is preferred)

c) allow simultaneous use of all 5 WDS spectrometers, EDS, reflected and transmitted light optics

d) crystals must flip in any spectrometer position using both computer and manual control

e) reproducibility of spectrometer repeatability shall meet the following criteria using the LiF, PET and TAP crystals measuring Fe and Ca on LiF, Si and Ca on PET, and Mg and Si on TAP using 15 KeV and 30 nA beam current :

- with no detector slits or wide open slits, first determine the peak location and the location at one-half the maximum (either side) for each pair of elements on each crystal

- count for a period of time sufficient to achieve 0.5 % relative standard deviation.

- detune the spectrometer, position the spectrometer to the peak of element 1, position to the location at one-half maximum for element 1, position to the peak of element 2, position to the location at one-half maximum of element 2. Repeat 10 times from different starting points on the spectrometer. The peak intensities shall vary by less than 0.6 % (+/- 0.3 %) with 99 % confidence levels from the previous set and the one-half the maximum intensities shall vary by less than 1.2 % (+/- 0.6 %) at 99 % confidence levels without a backlash or re-peak procedure

- execute a crystal change (returning to the original crystal) on each spectrometer and immediately repeat the test in the paragraph above, Verify that the intensities measured vary less than 2 % (+/- 1 %) with 99 % confidence levels from the previous set without a backlash or re-peak procedure

f) agreement of simultaneous k-ratios between all WDS spectrometers on the same sample relative to the same standard must be better than 1 % (+/- 0.5 %) for major elements concentrations when a counting period sufficient to achieve 0.5 % relative standard deviation is used. This test shall be performed using LiF, PET and TAP crystals measuring Fe and Ca on LiF, Si and Ca on PET, and Mg and Si on TAP using suitable mineral standards

g) analyzing crystals must diffract symmetrically (documentation must be provided of count rates and P/B for at least two elements on each analyzing crystal in both mounting orientations). To be considered symmetrically diffracting, the count rates and P/B of each crystal in it's two orientations must be different by less than 6 % (+/- 3 %)

h) spectrometer resolution must be such that a measurement of the V Ka line on a Ti sample yields an apparent k ratio of less than or equal to 0.005 when operating with a 20 KeV, 15 nA beam under conditions at which measurements of Ti Ka yield the Vendor's and UCB's peak intensity and P/B ratio as specified in the table below :

i) each analyzing crystal count rate and P/B specification (as measured on pure metals unless otherwise noted) must meet or exceed 80% of the Vendor's specifications and the average of all crystals on each spectrometer must meet or exceed 100 % of the Vendor's specifications and as specified below :

* 60.0 - 70.0 2d space

j) verify that the instrument is aligned so that all crystals peak at an identical stage Z position +/- 1 um by scanning the Z axis over a +/- 20 um range while counting x-ray signals

k) the background linearity as determined by measuring the off-peak background intensities for Ga and As on a GaAs sample and a Ge sample shall produce statistically identical results

 

4. Secondary and backscattered electron digital imaging system :

a) secondary image resolution of 70 angstroms at 20 KeV or better using a tungsten filament on a sample of Au particles on carbon.

b) backscattered electron spatial resolution of 150 angstroms (0.015 um) or better at 25 KeV shall be performed using a sample of Au particles on carbon using a tungsten filament

c) backscattered electron atomic number resolution must be at least 0.1 Z at Z=29 or better (must easily contrast a/b brass sample)

d) slow, fast, TV, and photographic scan rates provided for secondary electron and backscattered electron image display

e) SE and BSE image distortion as determined by viewing a ball bearing at 200X must be less than 3 % (+/- 1.5 %) on the CRT

f) dedicated color monitor for imaging BSE or SE signals (14" minimum)

 

5. Light-optical image system :

a) normal incidence (90 degrees) high magnification (300-400x), reflected and transmitted (both plane and polarized light sources for transmitted light viewing, allowing observation of the sample both during positioning and WDS/EDS analysis and/or SE/BSE/x-ray imaging. Low power light optics is preferred but not required.

b) high resolution color television camera and monitor (14" minimum) as primary device for image observation; microscope eyepiece attachment as optional, secondary observation device

c) optical resolution of 0.7 microns and flat field of view. In addition, as a particle is brought in and out of focus, it' s image shall concentrically collapse and expand without noticeable X or Y motion

d) optical depth of field of less than +/- 1 um at 300 - 400 X

e) the image shift in transmitted light must be less than 1 um as the polarizers are rotated

 

6. Automatic vacuum control system :

a) separate roughing and backing belt driven (NOT direct drive) mechanical rotary pumps (Welch 1397 preferred) both at least 500 l/m pumping speed and a maximum base pressure of 10 microns or less. The Vendor must provide hose connections and in-line anti-vibration dampeners with standard ISO connections (NW25 or equivalent).

If the vendor does not wish to supply the belt driven pumps as an option, the quote should clearly indicate the corresponding price reduction and UCB will supply the specified pumps with the specified ISO connections.

b) water-cooled oil diffusion pump with a provision for trapping of oil vapors using a baffle or trap device, and capable of operating the column and gun at a pressure of 5 x 10-6 Torr (5 x 10-7 preferred) or better after 30 minute pump down with hot diffusion pump

c) protection against power, water supply , compressed air or vacuum failure

d) electron gun and sample airlock chambers isolatable for filament and sample change

 

7. Specimen chamber with specimen exchange system :

a) using airlock and automated vacuum system, allowing exchange without venting entire spectrometer chamber

b) a minimum of 2 complete sample holders shall be provided and accommodate a variety of sample shapes and sizes for :

- at least 5 (6 preferred) 25mm diameter round thin/thick sections simultaneously

- at least 1 (2 preferred) standard petrographic rectangular thin plus 2 25mm round thin/thick (15mm) sections simultaneously

- the vendor shall also include an additional blank sample holder to allow for non-standard size samples

c) both sample holder systems must allow observation by electron and light (reflected and transmitted) optical systems without equipment change

d) sample exchange by way of airlock shall take no longer than 3 minutes.

 

8. Sample stage/motor system :

a) high speed motors (optical encoder position verification preferred). The stage must remain within 0.1 degrees level (+/- 0.05 degrees) relative to all spectrometer take off angles at all times. This shall be verified by measuring k-ratios for each spectrometer tuned to the same element (see item 3f). For this reason, there shall be NO stage tilt option in the sample stage assembly

b) minimum of 15 mm/sec speed (18 mm/sec preferred) and less than or equal to +/-1 micron reproducibility (+/- 0.5 micron preferred) for X, Y, and Z axis positioning as determined by driving from a point of interest to stage limits and back to the point of interest at 10,000X in SE image mode

c) after the above test, the stage and beam position shift shall be less than +/- 1 micron after 30 minutes as viewed in SE at 10,000X

d) trackball or joystick for manual stage adjustment of X and Y axes simultaneously at all times

e) the sample stage shall be supplied with either or both an LN2 cold trap finger and/or an air jet system to provide anti-contamination for the samples

f) an automatic focus device or system for sample stage focusing of the optical image shall be supplied

 

9. Instrument control and data interface :

a) all automation, acquisition and control functions of the Vendor's instrument (motor automation, PHA/counting, column/beam control, etc.) shall be specified and documented in English

b) complete documentation of interfaces and communication protocols to main instrument microprocessor(s) and/or hardware systems and subsystems shall be provided in English to allow UCB the option to interface directly to the probe hardware in the future. A non-disclosure agreement can be negotiated with UCB if required by the Vendor.

 

H. Quantitative acceptance tests to be performed by UCB :

The following analytical tests shall be performed for evaluation of the quantitative analysis and automation system at UCB :

- replicate analysis (10 seconds counts on-peak and off-peak will be made on standards for Mg (MgO), Al (Al2O3), Si (SiO2) and Fe (synthetic fayalite). This will be followed by 20 analyses of a mineral standard selected by UCB with the stage programmed to move to various points over the sample. The standard analyses will be repeated. The operating conditions will be 15 KeV and 5 - 50 nA in a fully automated mode. Automatic control of the beam current and beam focus shall be possible for both standards and unknowns during the automation.

- the raw intensities and backgrounds will be printed out along with the integrated beam current. Quantitative analyses for all elements in oxide weight percent of both the standards and unknowns will be printed out along with the averages, standard deviations, standard errors, P/B, k-ratios, ZAF correction factors and for the standards the variance from the value entered in the standard database for each element

- the mole percents, formula based on oxygen (if applicable to the sample), results in elemental weight percent (including O), detection limits at several different confidence levels and level of homogeneity will be calculated and displayed

- this procedure shall be repeated using additional elements (2 per spectrometer) and additional standards. The standards and unknown analyses will be automated and repeated at least 10 times for an overnight run without operator intervention

 

I. Additional Equipment Options :

In addition to the standard equipment necessary to meet the above specifications, the quotation should also include the following instrument options, unless they are already included as standard equipment :

1. A water recirculator for instrument cooling

2. An extra tungsten filament "wehnelt" assembly for quick change of the filament

3. A 1 year full coverage warranty (parts and labor) on the entire instrument to begin after the acceptance of the instrument by UCB, followed by 2 years of full coverage warranty (parts and labor) on the spectrometer and stage hardware and motors (and optical encoders if supplied)

 

J. Miscellaneous :

If this Purchase Order, including those documents forming a part hereof by reference or incorporation, provides for or requires the submission of any work to UCB for approval, any such approval given by UCB prior to final acceptance shall not relieve the seller of its responsibility for complying with the specifications and other provisions of this Purchase Order. Any such approval shall not be construed as an assumption by UCB of the responsibility that such work complies with or

Back To EPMA Home Page

Back To Department of Earth and Planetary Science Home Page

The Department of Earth and Planetary Science
Room 301, McCone Hall
The University of California
Berkeley, CA 94720-4767

Copyright 1998, The Regents of the University of California