A New Method for the Eliminaion of the Wall Effect in Proportional Counter

1976 ◽  
Vol 20 ◽  
pp. 555-563 ◽  
Author(s):  
K. Sipilä ◽  
E. Kiuru
Keyword(s):  
Proportional Counter ◽  
Dead Zone ◽  
Low Energy ◽  
Wall Effect ◽  
Cylindrical Shape ◽  
X Ray ◽  
Detector Pulse ◽  
Proportional Counters ◽  
And Performance ◽  
X Ray Absorption

The wall effect present in the gas-filled proportional counters and the low-energy background caused by it are well-known disadvantages. In this paper a method is presented to define the radial position of a single X-ray absorption in ordinary proportional counters. The method utilizes the variation in detector pulse collection times due to the electron diffusion. This variation can be determined with a specially constructed risetime analyzer which effectively forms a dead zone of cylindrical shape inside the detector. The properties and performance of the method are demonstrated. In the experiment performed the signal to background ratio was improved by a factor of twenty.

Model for low-energy electronic states probed by x-ray absorption in high-Tccuprates

1992 ◽  
Vol 45 (17) ◽  
pp. 10032-10050 ◽  
Author(s):  
Mark S. Hybertsen ◽  
E. B. Stechel ◽  
W. M. C. Foulkes ◽  
M. Schlüter
Keyword(s):  
Electronic States ◽  
Low Energy ◽  
X Ray ◽  
X Ray Absorption

Proportional Counter Parameters

1972 ◽  
Vol 16 ◽  
pp. 37-52 ◽  
Author(s):  
A. J. Burek ◽  
R. L. Blake
Keyword(s):  
Proportional Counter ◽  
X Rays ◽  
X Ray ◽  
Proportional Counters

AbstractA flow proportional counter for ultrasoft x-ray applications has been constructed and used to measure proportional counter parameters in the ultrasoft x-ray region at atmospheric and subatmospheric pressures for counting gases of P-10 and methane. We find that at atmospheric pressures the parametrization given by Zastawny for describing gas amplification in proportional counters applies and have measured values for the parameters for P-10 and methane. For subatmospheric pressures the Zastawny parameters are inadequate. A new parametrizatlon is required. In addition, the linearity of the detector for x-rays of energies of 15 KeV to 0.5 KeV was measured for pressures ranging from 750 Torr to 150 Torr and found to be excellent in all pressure regions.

A track length estimator method for dose calculations in low-energy X-ray irradiations: implementation, properties and performance

2015 ◽  
Vol 25 (1) ◽  
pp. 36-47 ◽  
Author(s):  
F. Baldacci ◽  
A. Mittone ◽  
A. Bravin ◽  
P. Coan ◽  
F. Delaire ◽  
...  
Keyword(s):  
Low Energy ◽  
Track Length ◽  
Dose Calculations ◽  
X Ray ◽  
And Performance

scholarly journals The SPECIES beamline at the MAX IV Laboratory: a facility for soft X-ray RIXS and APXPS

2017 ◽  
Vol 24 (1) ◽  
pp. 344-353 ◽  
Author(s):  
Samuli Urpelainen ◽  
Conny Såthe ◽  
Walan Grizolli ◽  
Marcus Agåker ◽  
Ashley R. Head ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
Unique Property ◽  
Unique Combination ◽  
X Ray ◽  
Fast Switching ◽  
X Ray Scattering ◽  
And Performance ◽  
Ring Species ◽  
X Ray Absorption

SPECIES is an undulator-based soft X-ray beamline that replaced the old I511 beamline at the MAX II storage ring. SPECIES is aimed at high-resolution ambient-pressure X-ray photoelectron spectroscopy (APXPS), near-edge X-ray absorption fine-structure (NEXAFS), X-ray emission spectroscopy (XES) and resonant inelastic X-ray scattering (RIXS) experiments. The beamline has two branches that use a common elliptically polarizing undulator and monochromator. The beam is switched between the two branches by changing the focusing optics after the monochromator. Both branches have separate exit slits, refocusing optics and dedicated permanent endstations. This allows very fast switching between two types of experiments and offers a unique combination of the surface-sensitive XPS and bulk-sensitive RIXS techniques both in UHV and at elevated ambient-pressure conditions on a single beamline. Another unique property of the beamline is that it reaches energies down to approximately 27 eV, which is not obtainable on other current APXPS beamlines. This allows, for instance, valence band studies under ambient-pressure conditions. In this article the main properties and performance of the beamline are presented, together with selected showcase experiments performed on the new setup.

scholarly journals Soft X-ray absorption spectroscopy in the low-energy region explored using an argon gas window

2020 ◽  
Vol 27 (4) ◽  
pp. 959-962
Author(s):  
Masanari Nagasaka
Keyword(s):  
Absorption Spectroscopy ◽  
Energy Region ◽  
Low Energy ◽  
X Rays ◽  
Argon Gas ◽  
X Ray ◽  
First Order ◽  
Helium Gas ◽  
Transmission Window ◽  
X Ray Absorption

The soft X-ray region below 200 eV is important for investigating chemical and biological phenomena since it covers K-edges of Li and B and L-edges of Si, P, S and Cl. Helium gas is generally used as the soft X-ray transmission window for soft X-ray absorption spectroscopy (XAS) under atmospheric conditions. However, the helium gas window cannot be applied to XAS in the low-energy region since transmitted soft X-rays mostly consist of high-order X-rays due to the low transmission of first-order X-rays. In this study, the argon gas window is proposed as a new soft X-ray transmission window in the low-energy region. High-order X-rays are removed by the absorption of the Ar L-edge (240 eV), and first-order X-rays become the major contribution of transmitted soft X-rays in the low-energy region. Under atmospheric argon conditions, the double-excitation Rydberg series of helium gas (60 eV), Si L-edge XAS of an Si3N4 membrane (100 eV) and S L-edge XAS of dimethyl sulfoxide gas (170 eV) are successfully measured, indicating that the argon gas window is effective for soft X-ray transmission in the low-energy region from 60 eV to 240 eV.

scholarly journals AP-XPS beamline, a platform for operando science at Pohang Accelerator Laboratory

2020 ◽  
Vol 27 (2) ◽  
pp. 507-514
Author(s):  
Geonhwa Kim ◽  
Youngseok Yu ◽  
Hojoon Lim ◽  
Beomgyun Jeong ◽  
Jouhahn Lee ◽  
...  
Keyword(s):  
High Resolution ◽  
Photoelectron Spectroscopy ◽  
Ambient Pressure ◽  
Experimental System ◽  
Photon Flux ◽  
Acceptance Angle ◽  
X Ray ◽  
Pohang Accelerator Laboratory ◽  
And Performance ◽  
X Ray Absorption

Beamline 8A (BL 8A) is an undulator-based soft X-ray beamline at Pohang Accelerator Laboratory. This beamline is aimed at high-resolution ambient-pressure X-ray photoelectron spectroscopy (AP-XPS), soft X-ray absorption spectroscopy (soft-XAS) and scanning photoemission microscopy (SPEM) experiments. BL 8A has two branches, 8A1 SPEM and 8A2 AP-XPS, that share a plane undulator, the first mirror (M1) and the monochromator. The photon beam is switched between the two branches by changing the refocusing mirrors after the monochromator. The acceptance angle of M1 is kept glancing at 1.2°, and Pt is coated onto the mirrors to achieve high reflectance, which ensures a wide photon energy range (100–2000 eV) with high resolution at a photon flux of ∼1013 photons s−1. In this article, the main properties and performance of the beamline are reported, together with selected experiments performed on the new beamline and experimental system.

scholarly journals X-ray bursting activity in the BL Lacertae object PKS 2155-304

1986 ◽  
Vol 119 ◽  
pp. 267-268
Author(s):  
D. Maccagni ◽  
L. Chiappetti ◽  
L. Maraschi ◽  
D. Molteni ◽  
M. Morini ◽  
...  
Keyword(s):  
Exposure Time ◽  
Low Energy ◽  
Medium Energy ◽  
X Ray ◽  
Bl Lacertae ◽  
Bl Lac ◽  
Proportional Counters ◽  
Bursting Activity

The bright BL Lac object PKS 2155-304 (mv=13; z=0.117) was observed with EXOSAT at five epochs (1983 Oct. 31, Nov. 30, 1984 Nov. 6, 7 and 11), for a total of about 30 hours of exposure time. Here we present data and results obtained with the Low Energy (LE) telescopes, in the band 0.05–2. keV, and with the Medium Energy (ME) argon proportional counters in the range 1.–6. keV.

scholarly journals A Low Energy Gas Scintillation Proportional Counter for the SAX-X-Ray Astronomy Satellite

1990 ◽  
Vol 123 ◽  
pp. 457-461
Author(s):  
A.N. Parmar ◽  
A. Smith ◽  
M. Bavdaz
Keyword(s):  
Proportional Counter ◽  
Space Science ◽  
Low Energy ◽  
X Rays ◽  
Science Department ◽  
Energy Response ◽  
X Ray ◽  
Thin Plastic

AbstractThe payload of the italian/Dutch satellite SAX will include a set of four concentrators each with a geometric area of 90 cm2. Imaging GSPCs will be located at the focal planes of the concetrators. The Space Science Department of ESA will provide one of these GSPCs which will be sensitive to X-rays with energies between 0.1-10 keV. In order to achieve such a low-energy energy response, a driftless configuration and a thin plastic window have been adopted. At 6 keV the collecting area will be 50 cm2 and the energy and angular resolutions 8% and 1.6′ FWHM, respectively.

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