The marμX – a Turn-key System for X-ray Crystallography
Take a state-of-the-art micro-beam sealed tube generator with a specially designed high-performance optics, add a mardtb "desktop beamline" and a mar345 image plate detector to it plus a cryo-cooler, put it into a shiny cabinet and you are getting a truly powerful yet very affordable complete X-ray data collection system - just perfect for macro-molecular crystallography, powder diffraction and related fields.
No water and electrical installations required - it will fit anywhere in your lab. And: do forget about those maintenance budgets you are used to see elsewhere!
- Generator: Xenocs GeniX3D Cu HF (High Flux) micro-beam X-ray generator operating at 30 Watts, producing a microfocus spot with a size of 40 by 40 microns at the source. The new GeniX3D Cu HF source has been introduced in mid 2010 and replaces the GeniX Cu VHF. The new source makes use of another type of tube and newly designed optizimed optics. Despite of running at the lower power of 30 W (50 kV / 0.6 mA) instead of 50 W used by the old system, the generator delivers a higher photon flux at the sample (see application note mar.AN28Oct10).
- Optics: State-of-the-art Xenocs multi-layer optic producing a spot size at the sample of < 190 by 190 microns FWHM (specs: see below). Other configurations, e.g. for a parallel beam or a Mo source, are available on request.
- Detector: mar345 image plate detector with 345 mm diameter or a SX-165 single chip CCD detector with 165 mm diameter.
- Goniostat: mardtb “desktop beamline” multi-purpose goniometer system, optionally with the “easymount” or the marcsc sample changer extensions.
- Cryo-cooler: Optional Oxford Cryosystems “Cryostream 700” or “Cobra” low temperature unit.
- Table/enclosure: A functional and stable table with plenty of space for all electronics and attachments. Optional table top radiation enclosure.
- Dependable: Every single component of the system is renowned for its reliability, the one for the mar345 detector and the mardtb goniostat being proverbial.
- Performance: Let’s face it: would you have believed that a generator running at 30 Watts can beat another one running at 5000 Watts?
- No electrical installations: The entire system can be used on standard single-phae 220/110 V wall sockets with a 16A fuse.
- No water installations: Cooling of the anode is accomplished by a built-in water/air heat exchanger operating as closed circuit.
- Low power consumption: The generator runs at 30 kV / 0.6 mA, i.e. 30 Watts, less than a bright light bulb!
- No filament replacement: The sealed-tube of the generator has a life-time of 2-3 years and does not require maintenance during its lifetime.
- Compact design: The footprint of the entire system is 1.7 x 1 m². Basically, it will fit anywhere in your lab.
- Low noise: Due to limited cooling requirements, the noise generated by the system is far inferior as the one from rotating anode generators
- Low price tag: Complete crystallography setups have never been more affordable!
- Low maintenance costs: No water, little power consumption, no replacement filaments, no routine maintenance – you won’t find an X-ray equipment that is cheaper to keep running…
The Genix micro-beam generator together with a Xenocs multi-layer optic is a true alternative to modern rotating anode generators (RAGs). While there still is a performance gap to small-focus RAGs, the key question is:
Does a micro-beam sealed-tube generator allow to evaluate the diffraction power of small crystals?
The answer clearly is: yes, it does. This is because the generator delivers a very small beam with such a high brilliance that even very small crystals sized < 50 microns will see enough X-ray photons. This is achieved by a highly optimized combination of source and optics parameters. Please read the application notes for further details!
In experiments that we have carried out very carefully, we could show that the marμX system produces data comparable to traditional high-power rotating anode systems. In a test using lysozyme crystals it was possible to collect data of good enough quality for sulfur-SAD-phasing using only 90 degrees of data. The experiments are described in detailed in the application note mar.AN260107 from Jan 26, 2007.
In a second application note mar.AN070207 from Feb 07, 2007, a direct comparison between the marμX system and a rotating anode generator using the same experimental conditions (same crystals, exposure times, detector, etc.) revealed that small crystals produce superior data with the marμX system while the results for larger crystals are virtually identical.
In a third application note mar.AN20Jun08 from Jun 20, 2008, we compared the performance of the Xenocs FOX2D 10_30P optics and the latest model of the FOX3D 14_39P optics, which features an optimized high precision ellipsoidal substrate and a state-of-the-art multilayer to achieve a beam with improved focusing properties and high flux density. With the FOX3D optics we observed more than a 2-fold increase in observed diffraction as compared to the FOX2D optics, in particular when looking at small crystals. This brandnew optics narrows the gap to modern rotating anode generators, again.
In a fourth application note mar.AN28Oct10 from Oct 28, 2010, we compared the performance of the Xenocs GeniX3D Cu HF source running at 30 W with the previous Genix Cu VHF source running at 50 W. The new source entirely replaces the VHF model. It features a new tube and newly designed optics. In the application note we describe data collections from small molecule crystals of various forms and sizes. The new source proves to deliver more usable X-ray photons at the sample in the order of magnitude of 1.5. This makes the choice of a small scale generator setup even more attractive.
|X-ray source:||GeniX3D Cu HF micro-beam 50 kV / 0.6 mA|
|Beam size at sample||175 x 175 μm|
|Beam divergence||6 x 6 mrad2|
|Total flux||> 4.3 x 108 photons/sec|
|Flux with 100 μm² at focal spot||> 9 x 107 photons/sec|
|Anode coupling||built-in water/air refrigerated chiller|
|Mirror protection||diaphragm vacuum pump with interlock to shutter|
|Detector:||mar345 image plate|
|Plate diameter||345 mm|
|Pixel size||100 or 150 micron (software selectable)|
|Cycle times||34-108 sec (depending on diameter and pixelsize)|
|Dynamic range||17 bits (1-131000)|
|Sensitivity||1.5 X-ray photons equivalent|
|Goniostat||mardtb multi-purpose goniometer with automatic X-ray beam alignment and continuous monitoring of the primary beam intensity|
|Optional accessories for mardtb||- built-in motorized goniometer head
- easymount: automated sample mounting system
- marcsc: cryogenic sample changer
|Cryo-cooler:||Oxford Cryosystems Cryostream 700 (or Cobra)
|LN2 auto-refill system||Capacitance based level control
|Experimental table:||- 1700 x 1000 x 800 mm (w:d:h), stainless steel
- magnetic table top and aluminum table frame
|Options:||Radiation enclosure with sliding doors
and shutter interlock system
Please, download the marμX product brochure for a summary of the product properties and specifications as well as product application notes that demonstrate the capabilities of the system.
- Product brochure (pdf: 709 KB)
- Drawing of table and enclosure (pdf: 109 KB)
- Application note mar.AN260107 (pdf: 990 KB)
"Sulfur-SAD-phasing of hen egg lysozyme with Cu-radiation obtained in-house with a GeniX micro-beam generator"
- Application note mar.AN070207 (pdf: 611 KB)
"Comparison of a conventional rotating anode generator with a Xenocs GeniX micro-beam generator"
- Application note mar.AN20Jun08 (pdf: 1.6 MB)
"Comparison of the Xenocs 2D and 3D optics on a marμX data collection system"
- Application note mar.AN28Oct10 (pdf: 1.9 MB)
"Comparison of the GeniX3D Cu HF beam delivery system with the GeniX Cu VHF system"