Medipix1

[image: mp1 chip]

Photograph of the Medipix1/PCC chip (64x64 pixels)

[image: Medipix logo]

One of the first Medipix1 raw images using a 90Sr source (electrons) centred in the middle of the red pixel part. The different colours represent different number of counts per pixel. The image is formed by a 500 μm thick tungsten wire bent to an 'm'. The small spot in the bottom left corner shows the absorption of the conductive glue used to fix the bias wire to the 200 μm thick GaAs sensor.

[CERN group]

[image: 4 shells]

Four radiographs of four different sea shells taken with a radioactive 109Cd source. A Medipix1 chip bump-bonded to a 300 μm thick silicon sensor was used. The thresholds of the pixels were adjusted beforehand and a flat field correction applied offline. No other image processing was employed.

[Pisa group]


[image: x-rayed sardine and photo]

X-ray image of a sardine (top; see photograph below). This image was taken using a Mo X-ray tube + 30 ┬Ám Mo filter. The following tube settings were used: 25 kV, 10 mAs, distance target-object ~50 cm. The Medipix1 detector (Medipix1 ASIC bump-bonded to a 300 μm thick silicon sensor) was stepped for one detector width in x and half a detector width in y; aquisition time per image: 500 ms. No image correction was used (raw data!). The thickness of the fishbones corresponds roughly to the pixel size.

[CERN group]

[image: x-rayed frog leg and photo]

X-ray image of froglegs (top; see photograph below). This image was taken using a Mo X-ray tube + 30 μm Mo filter. The following tube settings were used: 25 kV, 10 mAs, distance target-object ~50 cm. The Medipix1 detector (Medipix1 ASIC bump-bonded to a 300 μm thick silicon sensor) was stepped for one detector width in x and half a detector width in y; acquisition time per image: 500 ms; flat field correction, median filter.

[CERN group]


[image: flies]

X-ray image (lower image) of a fly (see optical image above) using a 55Fe radioactive source (5.9 keV X-rays!) and the Medipix1 chip bump-bonded to a 300 μm thick silicon sensor.
To reach such low energies the threshold adjustment facility of Medipix1 was used. Moreover, a flat field correction was applied, but no filtering.
The acquisition time chosen for this image was 5 hours (source of 4.6 MBq relatively far away for uniform illumination) which shows the stability of the system. The average number of counts in the background was ~23000.

[CERN group]

[image: octoputs eggs]

Right: Medipix1 image of five octopus vulgaris eggs (white) labelled with 14C-leucyne immersed in nutrient solution (pink) during a dynamic uptake test.
Left: Photograph of the culture dish showing the cells in the solution.

[Napoli group]


[image: sheep spine]

X-ray image of a sheep's spine taken using a novel laser-driven micro-dose X-ray source (Univ. Claude-Bernard, Lyon1; see NIM A 452 (2000) 361-370 for details about the source). An assembly with a silicon sensor was used and a median filter applied. The alveoles are clearly visible.

[CERN group]

[image: carbon microscale]

Image of a 14C microscale (in bands of different specific activity ranging from 1.1 to 25.9 kBq/g) used for calibration of beta-autoradiography systems.

[Napoli group]

[image: integrated circuit]

Image of an integrated circuit (left: without flat field correction, right: with flat field correction) obtained with a 241Am radioactive source and a 300 μm thick Si detector.

[Napoli group]


[image: circuit board]

Detail of a 2-sided PCB-board (red rectangle in the lower optical image) taken with a Medipix1/silicon assembly. The source consisted of a dental X-ray tube applying an acceleration voltage of 70 kV. Threshold adjustment and flat field correction were applied as well as a median filter. The electronics components can easily be identified as well as the fine interconnection paths.

[Glasgow group]


[image: lead bar]

Image of a lead bar pattern. The Medipix1/silicon assembly was illuminated by a 13 keV synchrotron beam. The spatial frequency is 1.8 lp/mm, i.e. 30% of the pixel sampling frequency. The measurement yields a contrast modulation of 80%. The pixellated bar edges are characteristic of scatter-free detectors whose resolution is only limited by the pixel aperture.

[ESRF group]

[image: fuse]

X-ray image from a 1.6 A fuse (20 mm x 5 mm) taken with Medipix1 bump-bonded to a silicon detector. The X-ray source consisted of a Mo tube (30 kVp, 25 mAs) with 30 μm Mo filtration resulting in 1 mGy dose just above the object. The twisted wire inside the fuse can clearly be seen and one will state that the fuse is blast (top left corner). A bubble with residuents from this blast is seen approximately in the middle of the fuse attached to the glass tube (top).

[Erlangen group]

[image: screw]

M2-screw (6 mm long) imaged with a 241Am radioactive source using a 200 μm thick GaAs sensor (background subtracted). For representation a contour plot was chosen.

[CERN group]


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Medipix2


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Medipix3


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