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Development of an X-ray HARP-FEA detector system for high-throughput protein crystallography.

Miyoshi T, Igarashi N, Matsugaki N, Yamada Y, Hirano K, Hyodo K, Tanioka K, Egami N, Namba M, Kubota M, Kawai T, Wakatsuki S - J Synchrotron Radiat (2008)

Bottom Line: The combination of the membrane avalanche effect with a single driven FEA has several advantages over currently available area detectors, including higher sensitivity, higher spatial resolution and a higher frame rate.Preliminary evaluation of the detector has been carried out and its effectiveness has been confirmed.Next, diffraction images were measured with continuous rotation of a protein crystal, and the images were compared with those measured by the existing CCD detector; the system successfully obtained high-spatial-resolution images.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan. tmiyoshi@post.kek.jp

ABSTRACT
A new detector system for protein crystallography is now being developed based on an X-ray HARP-FEA (high-gain avalanche rushing amorphous photoconductor-field emitter array), which consists of an amorphous selenium membrane and a matrix field emitter array. The combination of the membrane avalanche effect with a single driven FEA has several advantages over currently available area detectors, including higher sensitivity, higher spatial resolution and a higher frame rate. Preliminary evaluation of the detector has been carried out and its effectiveness has been confirmed. Next, diffraction images were measured with continuous rotation of a protein crystal, and the images were compared with those measured by the existing CCD detector; the system successfully obtained high-spatial-resolution images. Using shutterless measurement, the total measurement time can be reduced significantly, making the method appropriate for high-throughput protein crystallography. The X-ray HARP-FEA detector is an attractive candidate for the next generation of X-ray area detectors.

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Schematic diagram of the HARP–FEA detector.
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fig1: Schematic diagram of the HARP–FEA detector.

Mentions: Fig. 1 ▶ shows a schematic diagram of the HARP–FEA detector; Fig. 2 ▶ is a photograph of a prototype. A HARP membrane on the original HARP-TV is formed on a glass plate. Since low-energy X-rays cannot penetrate a thick glass plate, a thin beryllium membrane is used for the formation of the HARP membrane. When high voltage is applied to the HARP, electron–hole (e–h) pairs generated by the X-rays produce additional e–h pair(s), and avalanche multiplication occurs. The accumulated charge is detected by electron beams from the field emitter array. There are two types of FEA, Spindt and HEED (high-efficiency electron emission device), whose difference is mainly in the shape of the array. A group of arrays forms a pixel, multiple pixels are gathered in an aligned signal circuit, and signals are sent from every circuit in series. A mesh electrode is used for focusing each pixel; this adjustment influences spatial resolution. The HARP–FEA detector is assembled in a camera box with readout electronics. On the camera, the HARP–FEA detector is surrounded by a large permanent magnet to focus all of the readout electron beams from the FEA. Because of the space required for the magnet, the distance between the surface of the camera and the beryllium membrane is large, about 30 mm.


Development of an X-ray HARP-FEA detector system for high-throughput protein crystallography.

Miyoshi T, Igarashi N, Matsugaki N, Yamada Y, Hirano K, Hyodo K, Tanioka K, Egami N, Namba M, Kubota M, Kawai T, Wakatsuki S - J Synchrotron Radiat (2008)

Schematic diagram of the HARP–FEA detector.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2394816&req=5

fig1: Schematic diagram of the HARP–FEA detector.
Mentions: Fig. 1 ▶ shows a schematic diagram of the HARP–FEA detector; Fig. 2 ▶ is a photograph of a prototype. A HARP membrane on the original HARP-TV is formed on a glass plate. Since low-energy X-rays cannot penetrate a thick glass plate, a thin beryllium membrane is used for the formation of the HARP membrane. When high voltage is applied to the HARP, electron–hole (e–h) pairs generated by the X-rays produce additional e–h pair(s), and avalanche multiplication occurs. The accumulated charge is detected by electron beams from the field emitter array. There are two types of FEA, Spindt and HEED (high-efficiency electron emission device), whose difference is mainly in the shape of the array. A group of arrays forms a pixel, multiple pixels are gathered in an aligned signal circuit, and signals are sent from every circuit in series. A mesh electrode is used for focusing each pixel; this adjustment influences spatial resolution. The HARP–FEA detector is assembled in a camera box with readout electronics. On the camera, the HARP–FEA detector is surrounded by a large permanent magnet to focus all of the readout electron beams from the FEA. Because of the space required for the magnet, the distance between the surface of the camera and the beryllium membrane is large, about 30 mm.

Bottom Line: The combination of the membrane avalanche effect with a single driven FEA has several advantages over currently available area detectors, including higher sensitivity, higher spatial resolution and a higher frame rate.Preliminary evaluation of the detector has been carried out and its effectiveness has been confirmed.Next, diffraction images were measured with continuous rotation of a protein crystal, and the images were compared with those measured by the existing CCD detector; the system successfully obtained high-spatial-resolution images.

View Article: PubMed Central - HTML - PubMed

Affiliation: Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan. tmiyoshi@post.kek.jp

ABSTRACT
A new detector system for protein crystallography is now being developed based on an X-ray HARP-FEA (high-gain avalanche rushing amorphous photoconductor-field emitter array), which consists of an amorphous selenium membrane and a matrix field emitter array. The combination of the membrane avalanche effect with a single driven FEA has several advantages over currently available area detectors, including higher sensitivity, higher spatial resolution and a higher frame rate. Preliminary evaluation of the detector has been carried out and its effectiveness has been confirmed. Next, diffraction images were measured with continuous rotation of a protein crystal, and the images were compared with those measured by the existing CCD detector; the system successfully obtained high-spatial-resolution images. Using shutterless measurement, the total measurement time can be reduced significantly, making the method appropriate for high-throughput protein crystallography. The X-ray HARP-FEA detector is an attractive candidate for the next generation of X-ray area detectors.

Show MeSH