AN ANALYTICAL XRAY SERVICES LABORATORY
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Posted by: In: Uncategorized 21 Jun 2017 0 comments Tags: , ,

KS Analytical Systems and Texray Laboratory Services are deeply invested in the future of science and technology in the USA. We work with undergraduate, graduate and post-doc students regularly and encourage them as much as possible with support through Texray as well as technical information. Watching XRD and XRF users in higher education develop and test their ideas is always interesting, but these are not the students who are being lost from STEM fields. The battleground for the engineers, chemists, and physicists of tomorrow is happening at a much younger age so we’re always looking for opportunities to support teachers who are working to show their students that these fields are not just endless equations and tedious experiments.

With the whole country waking up to the need for more STEM graduates, there’s no shortage of organizations and competitions set up to give kids a chance to get their hands dirty with technology. We started out by sponsoring a local high school robotics team and, most recently, a high school team entered in the NASA Human Exploration Rover Challenge. The video below is from last year and I love how they describe their early failures and determination to improve. These are not your ordinary shop-class kids. Most had never used even basic hand tools. This competition put them completely outside their comfort zone.

The 2017 competition brought new challenges and more restrictive design constraint intended to push the teams further into the realm of custom components. The obvious answer for most of these vehicles had been common bicycle wheels and tires from the beginning. Their light weight and high strength make them very attractive, but taking the easy way out is not what being an engineer, let alone a NASA engineer, is all about. Using the equipment and capabilities at hand the Parish Episcopal team developed a wheel that took everyone by surprise (including myself). Multiple layers of cardboard were sandwiched together and coated in a polymer bed-liner material intended for pickup trucks. The toothed pattern of the cardboard layers created exceptional traction and the rubber coating made them extremely durable. The 2017 rover was not without its weaknesses, but these wheels were a subject of interest to everyone from the spectators to the organizers. Parish fielded two teams which finished 26th and 27th out of a 99 team field which included universities and high schools from all over the world.

The first video is from a TED talk given by two of the older students in the program from 2016. The second is from the 2017 competition and includes some race footage.

I spend a great deal of time meeting with XRD and XRF users throughout the year, but usually in the context of some problem or time-sensitive project. Luckily I’ve been able to attend the Denver X-ray Conference fairly consistently over the last few years. It’s a great time to catch up with other users who are as deeply invested in X-ray spectroscopy and crystallographic analysis as we are. The vendors always put on a great show in the exhibit hall and poster sessions.

The first three days of the week are filled with technical workshops focused on an array of topics. There are always some introductory classes for both XRD and XRF for new users to attend and then there will be additional topics which are usually more advanced. The educational opportunities alone are well worth the attendance fee. Each session is run by an expert in the field and questions, even from industrial users, are welcomed. The sessions are strictly non-sales oriented as well which lends the event a very egalitarian feeling. See the full program here.

Plenary sessions and more sales-oriented meetings occur later in the week and are a great way to get a feel for the cutting edge technology being released by the various vendors. The exhibit hall opens a few days into the conference so everyone has a few days to see all the different booths. We always spend a great deal of time at the Materials Data, Inc and Bruker-AXS booths in particular.

The conference moves between Westminster, CO just North of Denver, Chicago, IL and Big Sky, MT. I’ve never made the trek up to Big Sky, but I hear it’s beautiful. Some attendees only come when it’s up there.

I’d love to connect with as many of our readers as possible so contact us if you’ll be there and I’ll be sure to see you while I’m at DXC-Big Sky!

A great many factors affect the quality of data one can collect on any given instrument, but there are times when simply holding the aliquot is a major hurdle. We spend a great deal of time working out the best ways to hold odd samples and even create custom hardware to do so in some cases. Click here for some of our other posts related to the various sample holders we work with. Choosing the best sample holder for a given project is one thing, but there are also times when a completely different stage is required.

The most common stage is the simple, single sample stage. This relies on three pins to define the plane of diffraction. The sample holder is pressed against these pins by a spring loaded plunger beneath it.

Posted by: In: Uncategorized 01 Apr 2017 0 comments

The days of inconsistent coffee are over. The world’s leader in elemental and crystallographic analysis instrumentation is bringing the same cutting edge technology used in their research-grade laboratory instruments to the food service sector. The “Brewker” B8 percolation instrument has revolutionized the hot beverage industry by applying the same stringent repeatability techniques employed in their XRD and WDXRF machines to the humble coffee maker.

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Key features:

  • Six lab-grade thermocouples monitor water temperature throughout the brewing process to ensure optimal consistency from the top of the grounds to the bottom.
  • The internal water purification module produces high-grade distilled water from any tap source. Subsequent particulate filtration, UV sterilization and ion-exchange operations are performed simultaneously because honestly, if you wouldn’t put it in your HPLC, you shouldn’t put it in your coffee.
  • Hall effect flow rate sensing controls the filling rate to within 0.001 L/m. A variable speed pump with high frequency bypass system adjusts fluid pressure 200 times every second.
  • Primary water is heated by the integrated inductive furnace and platinum boiler for the highest purity possible.
  • The effects of ambient temperature fluctuations are mitigated by the in-situ microwave temperature stabilization system which maintains water temperature to within 0.02 degrees C from the boiler to your cup.
  • The “Grounds Control” system integrates a proprietary laser particle size and CCD based shape analyzer for ultimate control.
  • A fully automated Nitric acid flush cycle guarantees that residual contamination does not exceed 100ppt from cup-to-cup.

 

Optional:

  • For the highest quality coffee possible, “Brewker” exclusive Poly Crystalline Diamond (PCD) coated Pt coffee mugs are recommended.
  • Basic and premium coverage support contracts are available on an annual basis. Remote diagnostics are possible when the B8 is connected to your site LAN.
  • All temperature and flow rate tolerances may be reduced by 50% when the “Brewker” B8 is equipped with the optional line voltage conditioner and UPS module.
  • The “Starbucks” discrimination function extends the Grounds Control capabilities to include protection against inferior, consumer-grade coffees.
  • GC/Mass Spec and ICP quality assurance system analyzes aromatics and final composition.
  • For the ideal grind, there’s no better option than the new McCone Micronizing coffee grinder. The combined shearing and impact action of 50 individual elements offers unparalleled particle size and shape consistency.
  • Free NSF grant proposal consultation for all degree-granting academic institutions! The only thing that makes this coffee taste better is knowing that the American taxpayer funded it!

IQ/OQ/PQ documentation is available along with full 21 CFR Part 11 data logging and audit trail generation. Don’t let your break room be the weak link in your GMP protocol.

Contact our sales department for a quote today. You can’t put a price on the world’s most precise cup of coffee, but you’d better believe we’re going to try.

The dreaded “amorphous” hump created by x-rays scattering off plastic sample holders has plagued XRD users for decades. It’s a serious enough problem that we make a good volume of these holders from Aluminum which works very well for loose powders. The plastic scatters xrays at around 13 degrees 2Theta (Cu anode tube) which make a real mess of most geological patterns and isn’t fun to model out for Rietveld refinement. Zero background holders like our ZBH-32 work wonderfully in standard sample stages designed for a single sample at a time, but the large plate isn’t compatible with the autosampler.

I recently had a request for a hybrid holder which would allow for analysis of very small volumes of materials while retaining compatibility with the autosampler. This is almost identical to our standard powder holders, but with a well designed specifically for our small ZBH plate.

Key features include:

  • 6061-T6 Al material (anodized or as-machined)
  • Si(510) plate
  • Raised sample well minimizes the area of the sample holder in the plane of diffraction. (Original Siemens design)
  • Beveled well walls minimize the area of Al in the plane of diffraction
  • Other small modifications are made to improve reliability of these holders in the autosampler

One of the fundamental facts of lab-based X-ray production is that our x-ray tubes emit much more than the pure KA1 lines we rely on for material characterization and quantification. Most XRD users are familiar with techniques and hardware for the reduction or elimination of KB1, W LA1 and Bremsstrahlung, but take for granted the inseparable pair of KA1 and KA2 (referred to as the “doublet”). Luckily for us, these energies are present in strict proportion such that we can factor their paired presence into most XRD analysis to the point that one might barely notice their effect. However, the fact remains that we will see peak broadening at lower angles and completely independent additional peaks at higher angles due to this superfluous discrete emission.

Separating the doublet cannot be accomplished electronically or through absorption/attenuation such as might be effective for KB1 energies. It must be done in the primary-beam with an additional diffraction event. Primary-beam monochromators are generally classified by the number of diffraction events required for a photon to pass completely through the device. Single-bounce, 2-bounce and 4-bounce geometries are common with the latter providing the best energy resolution allbeit the lowest intensity (photon flux). My limited experience suggests that while the single-bounce models retain enough intensity to have some application in powder XRD, the others are relegated to HR-XRD applications such as XRR.

The alignment for any of this hardware is not for the faint of heart as it begins with coarse adjustments using fluorescent screens in the beam path. This was essential for us given how dramatically misaligned the monochromator had become after so many attempts to bring it back into operation. We actually needed our SDD system to verify that we were tuning for Cu KA1 energy rather than the KB1 emissions because some of the most basic aspects of the alignment had pushed way beyond their intended position.

Along the way we built ourselves a motorized remote adjustment tool which we’ll return to the user as small adjustments are required on a regular basis with this kind of monochromator to retain maximum intensity. It’s quite useful and even versatile enough to allow for the adjustment of multiple control knobs.

One final note regarding intensity. It’s easy to get excited about energy resolution like this, but bear in mind that we’re looking at ~20x reduction in intensity due to the inherent losses involved in the primary diffraction event. This data was collected at 10x the normal speed and at half the normal 2Theta step increment so it looks very good, but one would need a compelling reason to slow their data collection this much.

Another side effect of performing your energy discrimination in the primary beampath is that other issues such as fluorescence effects (incident x-rays exciting elements in the sample causing high background intensities) are harder to avoid than they would be with a diffracted-beam monochromator. The 4x reduction in intensity inherent in the diffracted-beam monochromatization makes it a poor choice to eliminate these effects when the incident intensities are already so low. We recommend energy-dispersive detectors such as our SDD-150 to eliminate extraneous energies without sacrificing net intensity. We’ve also worked with the Bruker LynxEye XE-T detector which has a very high energy resolution compared to other position sensitive detectors (PSD). Contact KS Analytical Systems for more information on these options.

FCT 0027 Xray decal visual croppedWe’ve been working with XRD machines for about 40 years now and to be quite honest, very little has changed. Most of the really exciting advancements have been software based, but there have certainly been changes to the hardware as well. We’ve introduced a few ourselves such as the KSA-SDD-150 detector. Automatic anti-scatter and divergence slits, additional axes and degrees of control have all increase the versatility of these instruments and opened them up to more advanced and unique experiments, but nothing has had an effect matching the new crop of Position Sensitive Detector (PSD). These have been around for decades, but didn’t really become popular until the a solid state version was introduced. There are still some trade-offs as mentioned in our KSA-SDD-150 post, but when you need speed, a PSD is the way to go.

Until recently, the only option for clients looking for this kind of speed was either a new XRD or a refurbished Bruker D8 system with a LynxEye or Vantec-1. While the D8 is a great machine and the LynxEye is a world class detector, the cost is usually too much for academic or small labs to bear. This has all been changing recently with the introduction of a truly aftermarket detector system from FCT ACTech. No other company that we’re aware of has worked so hard to make their hardware as turnkey as possible so the user isn’t left holding a box of parts and an instruction manual.

We can now offer detector upgrades for D5000 Theta/Theta and D5000 T2T systems with kits soon to be available for D500 systems as well. Software integration with DiffracPlus (standard software for Bruker XRD systems) is seamless and full integration with MDI Datascan is very close to completion. The future is very bright for users of these XRD systems.

Contact us for more information on these detectors


NovaculitesiliconKey features:

  • Data collection at 30x the speed of a standard point detector.
  • Dramatic increase in throughput
  • Plug-and-play retrofit
  • Maintenance free (no gas charge required)
  • Stand-alone operation for custom experiments
  • Excellent angular resolution

 

Technical Specifications:

  • Maximum count rate: 500Kcps / pixcel, 50Mcps global
  • Maximum scanning speed: 120 deg/min
  • Angular resolution: 0.06 deg at 200mm radius
  • Strip pitch: 120um
  • Number of channels: 96
  • Angular span: 3.3 degrees
  • Energy resolution: <10%
  • Energy range: 4.5KeV to 17KeV, efficiency at 30KeV is 10%
  • Compatible with all common XRD tube anodes including Cr, Fe, Co, Cu, Mo and W.

XRD sample holders are easily the most common items we’re asked to machine. Sometimes it’s because they’re no longer available, but usually, it’s to accommodate some special application. Sometimes it’s as simple as making them from Aluminum to allow for cleaning with acetone or other harsh solvents. Other times it has more to do with the clients preferred style of loading or sample volume. The end result is that there’s very little consistency so our process needs to be as versatile as possible. This video highlights the most recent process. It’s hard to see exactly what’s going on through the coolant, but this is a test run of a program to cut special holders for 25mm filter membrane holders for respirable silica measurements (or anything else one might want to deposit onto a 25mm filter). It’s cutting the bottom of one holder and the top of another (each on its own side of the fixture).  A full load of these produces 6 complete holders for every run.

Siemens goniometers are about as sturdy as they come. Large diameter gears and bearings spread out forces across a wide area resulting in smooth and stable performance as well as very high load handling due to the added leverage of this arrangement. For this reason, they’ll run for many years even after the grease inside has become hard and contaminated with dust. Most users don’t even know their goniometer is getting stiff until we check it during a PM. Catching this before the goniometer starts to hang up saves thousands of dollars and weeks of down time. Our goniometer rebuild service involves complete disassembly of the goniometer down to individual ball bearings for a thorough cleaning. We’ve tried to duplicate this procedure on-site with very limited success as the large components are best cleaned in a full size solvent bath and it’s special brackets are required to avoid concentricity issues during reassembly. All the critical electronics are replaced during reassembly along with fresh lubrication. The best case scenario is that we catch issue far enough in advance to get a matching replacement goniometer rebuilt and shipped out. There are too many variants to keep rebuilt units in stock all the time. This way we only need to come to the site once to swap the goniometer and perform the necessary zero alignment. The old goniometer goes back in the same crate and we’re done in a day or two. Waiting till a hard failure of the goniometer means a trip out to identify the problem and disassemble the system. The goniometer is shipped in for a rebuild which can easily take a few days to complete before being shipped back along with a second on-site visit. I’d estimate the extra cost to be right around $6k plus the cost of shipping and two weeks of downtime. We certainly don’t mind going this route, but if it were my money, I’d rather spend it on a comprehensive check of the machine rather than emergency services.

These pictures are from one of our first full rebuilds. This instrument was installed in a D5000-MATIC instrument at a cement plant. I’ve never seen so much dust inside a goniometer. Another particularly rough one was from a horizontal goniometer on a single-crystal system at a university. The students had a terrible habit of breaking Si(100) wafers and dropping them onto the goniometer face. Those little shards made their way into the bearings resulting in a rather perilous rebuild with shards of Si throughout it.

Posted by: In: Uncategorized 12 May 2016 0 comments

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Everyone wants to see their instrumentation perform at its peak, but all too often, the instrumentation is not the weak link in an analytical strategy. We see this in WDXRF and XRD, but recently had the opportunity to work with a client on their OES sample prep. This large steel mill has been using an automated Herzog sanding machine for many years. I’ve seen it in action and it’s a truly impressive tool. The engineers at Herzog have decades of experience building automated prep solutions and definitely worked hard on the design. However, speed was the key factor when this method was developed. There are few ways to prep a metal coupon faster than running it against a sanding belt. The sanding method had the added benefit of an extremely hard cutting medium (usually Al2O3) which meant that a single preparation procedure could be used for all steel grades and even worked when careless workers chose to water quench hot samples rather than allowing them to temper a bit by cooling in air (making them extremely hard). The downside of this method comes down to surface quality. Sanding will always leave a rough surface with linear troughs/grooves which create a variable surface area as well as shadowing. These effects are detrimental to light element sensitivity and as tolerances are tightened, the lab supervisors were forced to look to other methods.

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We began talking about this project over a year ago when the WDXRF user mentioned the lower detection limits that were soon to be implemented. I’d had some experience with sample preparation by milling, but usually more exotic alloys. There are certainly more than a few options available for automated milling, but their high cost and space requirements put them out of the running for this situation. My recommendation was to purchase a lower level CNC milling machine and automate as much of the process as possible to simplify operation and limit opportunities for error. I’m happy to say that the first tests earlier this month were a great success. The coupons come out with a very smooth surface in about the same amount of time it took to run through the sanding machine before.

IMG_20160428_120323There are still some things that bear consideration with milled samples. Not the least of which is contamination from the cutter. This client is unlikely to be bothered by Al2O3 from their sanding media, but small amounts of Tungsten Carbide steel (WC) rubbing into the surface could present an issue as cutters wear out. Luckily, the tools we’re using are indexable and not too expensive which allows users to change cutters frequently. It’s important to maintain a sharp edge and correct settings for this type of work in order to avoid “rubbing” through the material. This occurs when the tools is rotated too fast or fed too slowly. Material is pushed out of place rather than being cut. This causes contamination, premature tool wear and smearing of the surface. All of which have a detrimental effect on the analysis. I spent a solid day working out the initial conditions and there will still likely be many adjustments and changes before this becomes the primary production method.

 

All in all, this was a great project to work on. The improved detection limits will dramatically improve their analysis of light elements, the automated vise and mill will make it even easier and faster to prep material than before and we’ve done it all at a fraction of the cost expected. One thing I should note here is that this particular milling machine was chosen due to its exceptionally small size and low cost which were key requirements of this job. Given a less restrictive environment, I would have recommended a much different solution.