William Ku - Academia.edu (original) (raw)

Papers by William Ku

Nuclear Instruments and Methods, 1979

Page 1. IEEE Tranisactions on Nuclear Science, Vol. NS-26, No. 1, February 1979 AN IMPROVED LARGE... more Page 1. IEEE Tranisactions on Nuclear Science, Vol. NS-26, No. 1, February 1979 AN IMPROVED LARGE-AREA, GAS SCINTILLATION PROPORTIONAL COUNTER * William H.-M. Ku, David F. Anderson, Thomas T. Hamilton, and Robert Novick Abstract ...

Instrumentation in Astronomy V, 1984

ABSTRACT

IEEE Transactions on Nuclear Science, 2000

A large area imaging gas scintillation proportional counter (IGSPC) has been constructed for use ... more A large area imaging gas scintillation proportional counter (IGSPC) has been constructed for use in X-ray astronomy. The IGSPC consists of a gas scintillation proportional counter (GSPC) with a 1 wm coupled to a multiwire proportional counter (MWPC) via a calcium fluoride window. The MWPC, filled with a mixture of argon, methane, and tetrakis (dimethylamino) ethylene, detects the W photons emitted by the xenon gas in the GSPC. energy resolution of 17.5% (FWHM) and 1 . 9 mm (FWHM) spatial resolution at 1.5 keV. polypropylene window Over a sensitive area of 21 c d the instrument has a measured , 302

IEEE Transactions on Nuclear Science, 2000

The problems of developing large-area, gas-scintillation proportional counters with high resoluti... more The problems of developing large-area, gas-scintillation proportional counters with high resolution are considered. It is found that simple large-area, parallel-grid proportional counters suffer from a variation in gain over the counter window. Some success has been achieved in overcoming this problem by focusing the charge cloud as it drifts into the multiplication region. Measurements are reported for various mixtures of argon and xenon as well as pure xenon.

IEEE Transactions on Nuclear Science, 2000

An improved, large-area (285 cm2), gas scintillation proportional counter with a measured overall... more An improved, large-area (285 cm2), gas scintillation proportional counter with a measured overall energy resolution of 9.3% (FWHM) at 5.9 keV has been built. The rise-time resolution, 11.6% (FWHM) at 5.9 keV, of this counter is sufficiently well defined to allow the use of pulse-shape discrimination to reject 86% of the non-X-ray background events, while accepting 80% of the true

IEEE Transactions on Nuclear Science, 2000

We have mated a parallel-grid gas scintillation proportional counter (GSPC) to a multiwire propor... more We have mated a parallel-grid gas scintillation proportional counter (GSPC) to a multiwire proportional counter (MWPC) through a UV transparent window to produce a new instrument that combines the good energy resolution of the GSPC with the imaging capabilities of the MWPC. The imaging gas scintillation proportional counter (IGSPC) operates on the principle of detecting the centroid of the UV light excited by X-ray photons interacting in the noble gas of the GSPC with a UV sensitive gas [e.g. Tetrakis (dimethylamino) ethylene (TMAE)] in the MWPC. A prototype version of the counter has been built which yields a measured performance of 9% (FWHM) energy resolution and 0.9 mm (FWHM) spatial resolution at 6 keV. Further refinements of this counter and a new counter, designed for flight on a sounding rocket, should permit us to achieve 18% (FWHM) energy resolution and 0.6 mm (FWHM, spatial resolution at 1 keV.

IEEE Transactions on Nuclear Science, 2000

Page 1. IEEE Transactions on Nuclear Science, Vol. NS-26, No. 1, February 1979 A DRIFT MULTIWIRE ... more Page 1. IEEE Transactions on Nuclear Science, Vol. NS-26, No. 1, February 1979 A DRIFT MULTIWIRE PROPORTIONAL COUNTER FOR COSMIC SOFT X-RAY IMAGING Paul B. Reid, William H.-M. Ku, Knox S. Long, Robert Novick, and Ryszard L. Pisarski Abstract ...

Nuclear Instruments and Methods, 1979

Page 1. IEEE Tranisactions on Nuclear Science, Vol. NS-26, No. 1, February 1979 AN IMPROVED LARGE... more Page 1. IEEE Tranisactions on Nuclear Science, Vol. NS-26, No. 1, February 1979 AN IMPROVED LARGE-AREA, GAS SCINTILLATION PROPORTIONAL COUNTER * William H.-M. Ku, David F. Anderson, Thomas T. Hamilton, and Robert Novick Abstract ...

Instrumentation in Astronomy V, 1984

ABSTRACT

IEEE Transactions on Nuclear Science, 2000

A large area imaging gas scintillation proportional counter (IGSPC) has been constructed for use ... more A large area imaging gas scintillation proportional counter (IGSPC) has been constructed for use in X-ray astronomy. The IGSPC consists of a gas scintillation proportional counter (GSPC) with a 1 wm coupled to a multiwire proportional counter (MWPC) via a calcium fluoride window. The MWPC, filled with a mixture of argon, methane, and tetrakis (dimethylamino) ethylene, detects the W photons emitted by the xenon gas in the GSPC. energy resolution of 17.5% (FWHM) and 1 . 9 mm (FWHM) spatial resolution at 1.5 keV. polypropylene window Over a sensitive area of 21 c d the instrument has a measured , 302

IEEE Transactions on Nuclear Science, 2000

The problems of developing large-area, gas-scintillation proportional counters with high resoluti... more The problems of developing large-area, gas-scintillation proportional counters with high resolution are considered. It is found that simple large-area, parallel-grid proportional counters suffer from a variation in gain over the counter window. Some success has been achieved in overcoming this problem by focusing the charge cloud as it drifts into the multiplication region. Measurements are reported for various mixtures of argon and xenon as well as pure xenon.

IEEE Transactions on Nuclear Science, 2000

An improved, large-area (285 cm2), gas scintillation proportional counter with a measured overall... more An improved, large-area (285 cm2), gas scintillation proportional counter with a measured overall energy resolution of 9.3% (FWHM) at 5.9 keV has been built. The rise-time resolution, 11.6% (FWHM) at 5.9 keV, of this counter is sufficiently well defined to allow the use of pulse-shape discrimination to reject 86% of the non-X-ray background events, while accepting 80% of the true

IEEE Transactions on Nuclear Science, 2000

We have mated a parallel-grid gas scintillation proportional counter (GSPC) to a multiwire propor... more We have mated a parallel-grid gas scintillation proportional counter (GSPC) to a multiwire proportional counter (MWPC) through a UV transparent window to produce a new instrument that combines the good energy resolution of the GSPC with the imaging capabilities of the MWPC. The imaging gas scintillation proportional counter (IGSPC) operates on the principle of detecting the centroid of the UV light excited by X-ray photons interacting in the noble gas of the GSPC with a UV sensitive gas [e.g. Tetrakis (dimethylamino) ethylene (TMAE)] in the MWPC. A prototype version of the counter has been built which yields a measured performance of 9% (FWHM) energy resolution and 0.9 mm (FWHM) spatial resolution at 6 keV. Further refinements of this counter and a new counter, designed for flight on a sounding rocket, should permit us to achieve 18% (FWHM) energy resolution and 0.6 mm (FWHM, spatial resolution at 1 keV.

IEEE Transactions on Nuclear Science, 2000

Page 1. IEEE Transactions on Nuclear Science, Vol. NS-26, No. 1, February 1979 A DRIFT MULTIWIRE ... more Page 1. IEEE Transactions on Nuclear Science, Vol. NS-26, No. 1, February 1979 A DRIFT MULTIWIRE PROPORTIONAL COUNTER FOR COSMIC SOFT X-RAY IMAGING Paul B. Reid, William H.-M. Ku, Knox S. Long, Robert Novick, and Ryszard L. Pisarski Abstract ...