XRF spectrometers based on monolithic arrays of silicon drift detectors: elemental mapping analyses and advanced detector structures

We present a novel X-ray Fluorescence (XRF) spectrometer based on a ring-shaped monolithic array of silicon drift detectors (SDDs) with a hole laser-cut in the center and we show some examples of its application in elemental mapping analyzes. The X-ray excitation beam, focused by a polycapillary X-ray lens in a small and intense spot, reaches the sample going through the central hole of the detector chip. This geometry allows the collection of a large fraction of the fluorescence emitted by the sample and the reduction of the distance between the sample and the detector and, therefore of air absorption. These features, together with the high detection rate of the SDDs shorten the scanning time in elemental mapping. Some application examples of the new spectrometer in different research fields, from archaeometry to biology, are shown. Moreover, the paper introduces a new topology of the multi-element detector based on four SDDs monolithically integrated in a Silicon chip and surrounding a hole cut in its center. The structure of the four SDDs has been specifically designed to obtain very high energy-resolution and peak-to-background ratio. The first experimental results obtained with this detector are presented. It will equip a future version of the XRF spectrometer.

[1]  S. Buzzetti,et al.  High-speed FPGA-based pulse-height analyzer for high resolution X-ray spectroscopy , 2005, IEEE Transactions on Nuclear Science.

[2]  G. Pappalardo,et al.  A new portable XRF spectrometer with beam stability control , 2005 .

[3]  D. S. Walsh,et al.  An annular Si drift detector µPIXE system using AXSIA analysis , 2004 .

[4]  H. Soltau,et al.  A new XRF spectrometer based on a ring-shaped multi-element Silicon Drift Detector and on X-ray capillary optics , 2001, 2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310).

[5]  J. Schmalz,et al.  ArtTAX – a new mobile spectrometer for energy-dispersive micro X-ray fluorescence spectrometry on art and archaeological objects , 2001, Fresenius' journal of analytical chemistry.

[6]  Heike Soltau,et al.  Silicon drift detectors for high count rate X-ray spectroscopy at room temperature , 2001 .

[7]  Lothar Strüder,et al.  The quantum efficiency of pn-detectors from the near infrared to the soft X-ray region , 2000 .

[8]  V. V. Ivanov,et al.  Portable γ- and X-ray analyzers based on CdTe p–i–n detectors , 1999 .

[9]  F. Zaraga,et al.  In-situ, non-destructive identification of chemical elements by means of portable EDXRF spectrometer , 1998, 1998 IEEE Nuclear Science Symposium Conference Record. 1998 IEEE Nuclear Science Symposium and Medical Imaging Conference (Cat. No.98CH36255).

[10]  Carlo Fiorini,et al.  A new detection system for x-ray microanalysis based on a silicon drift detector with Peltier cooling , 1997 .

[11]  Heike Soltau,et al.  Silicon drift detectors for high resolution room temperature X-ray spectroscopy , 1996 .

[12]  G. Pappalardo,et al.  Feasibility study of a portable PIXE system using a210Po alpha source , 1996 .

[13]  G. Entine,et al.  New, high performance nuclear spectroscopy system using Si-PIN diodes and CdTe detectors , 1994 .

[14]  John L. Campbell,et al.  Particle-induced X-ray emission spectrometry (PIXE) , 1995 .