scholarly journals Simple, Immediate and Calibration-Free Cyclotron Proton Beam Energy Determination Using Commercial Targets

Instruments ◽  
2019 ◽  
Vol 3 (1) ◽  
pp. 20 ◽  
Author(s):  
Sergio do Carmo ◽  
Pedro de Oliveira ◽  
Francisco Alves
Keyword(s):  
Proton Beam ◽  
Beam Current ◽  
Simple Method ◽  
Thin Foils ◽  
Proton Beam Energy ◽  
Hpge Spectrometer ◽  
Absolute Efficiency ◽  
Calibration Free ◽  
Set Up ◽  
Energy Determination

This work presents a simple method for determining the energy of the proton beam in biomedical cyclotrons, using no additional experimental set-up and only materials from radioisotope routine productions that are therefore available on-site. The developed method requires neither absolute efficiency calibration nor beam current measurements, thus avoiding two major sources of uncertainty. Two stacks composed of natural titanium thin foils, separated by an energy degrader of niobium, were mounted in a commercial target and irradiated. The resulting activities of 48V were assessed by a HPGe spectrometer.

Proton Beam Energy Determination Using a Device for Range Measurement of an Accelerated High Energy Ion Beam

2011 ◽  
Vol 59 (2(2)) ◽  
pp. 679-685 ◽  
Author(s):  
Yeun-Soo Park ◽  
Jae-Hong Kim ◽  
Geun-Beom Kim ◽  
Bong-Hwan Hong ◽  
In-Su Jung ◽  
...  
Keyword(s):  
Proton Beam ◽  
Beam Energy ◽  
Ion Beam ◽  
High Energy ◽  
Range Measurement ◽  
Proton Beam Energy ◽  
Energy Determination

A simple method to measure proton beam energy in a standard medical cyclotron*

2009 ◽  
Vol 32 (2) ◽  
pp. 92-97 ◽  
Author(s):  
J. W. Burrage ◽  
A. H. Asad ◽  
R. A. Fox ◽  
R. I. Price ◽  
A. M. Campbell ◽  
...  
Keyword(s):  
Proton Beam ◽  
Beam Energy ◽  
Simple Method ◽  
Proton Beam Energy

A simple way for producing holographic filters suitable for image improvement

1978 ◽  
Vol 36 (1) ◽  
pp. 226-227
Author(s):  
K.-H. Herrmann ◽  
E. Reuber ◽  
P. Schiske
Keyword(s):  
Transfer Functions ◽  
Diffraction Order ◽  
Lateral Position ◽  
Simple Method ◽  
Spatial Frequencies ◽  
Resolution Electron ◽  
Wiener Filters ◽  
Image Improvement ◽  
Optical Reconstruction ◽  
Set Up

Aposteriori deblurring of high resolution electron micrographs of weak phase objects can be performed by holographic filters [1,2] which are arranged in the Fourier domain of a light-optical reconstruction set-up. According to the diffraction efficiency and the lateral position of the grating structure, the filters permit adjustment of the amplitudes and phases of the spatial frequencies in the image which is obtained in the first diffraction order.In the case of bright field imaging with axial illumination, the Contrast Transfer Functions (CTF) are oscillating, but real. For different imageforming conditions and several signal-to-noise ratios an extensive set of Wiener-filters should be available. A simple method of producing such filters by only photographic and mechanical means will be described here.A transparent master grating with 6.25 lines/mm and 160 mm diameter was produced by a high precision computer plotter. It is photographed through a rotating mask, plotted by a standard plotter.

Pump Performance Improvement by Restraining Back Flow in Screw-Type Centrifugal Pump

2005 ◽  
Vol 127 (4) ◽  
pp. 755-762 ◽  
Author(s):  
Yasushi Tatebayashi ◽  
Kazuhiro Tanaka ◽  
Toshio Kobayashi
Keyword(s):  
Pressure Fluctuations ◽  
Centrifugal Pumps ◽  
Two Phase ◽  
Simple Method ◽  
Back Flow ◽  
Pump Performance ◽  
Impeller Outlet ◽  
Pump Head ◽  
The Difference ◽  
Set Up

The authors have been investigating the various characteristics of screw-type centrifugal pumps, such as pressure fluctuations in impellers, flow patterns in volute casings, and pump performance in air-water two-phase flow conditions. During these investigations, numerical results of our investigations made it clear that three back flow regions existed in this type of pump. Among these, the back flow from the volute casing toward the impeller outlet was the most influential on the pump performance. Thus the most important factor to achieve higher pump performance was to reduce the influence of this back flow. One simple method was proposed to obtain the restraint of back flow and so as to improve the pump performance. This method was to set up a ringlike wall at the suction cover casing between the impeller outlet and the volute casing. Its effects on the flow pattern and the pump performance have been discussed and clarified to compare the calculated results with experimental results done under two conditions, namely, one with and one without this ring-type wall. The influence of wall’s height on the pump head was investigated by numerical simulations. In addition, the difference due to the wall’s effect was clarified to compare its effects on two kinds of volute casing. From the results obtained it can be said that restraining the back flow of such pumps was very important to achieve higher pump performance. Furthermore, another method was suggested to restrain back flow effectively. This method was to attach a wall at the trailing edge of impeller. This method was very useful for avoiding the congestion of solids because this wall was smaller than that used in the first method. The influence of these factors on the pump performance was also discussed by comparing simulated calculations with actual experiments.

A Simple Approach to the Theory of Secondary Flows

1954 ◽  
Vol 5 (4) ◽  
pp. 218-234 ◽  
Author(s):  
J. H. Preston
Keyword(s):  
Simple Approach ◽  
Secondary Flows ◽  
Large Deflections ◽  
Simple Method ◽  
Vortex Sheets ◽  
Trailing Edges ◽  
Secondary Motion ◽  
Set Up ◽  
Uniform Stream

SummaryA simple method is developed for computing the trailing vorticity which arises when a non-uniform stream is turned.It is shown that, for a sudden and constant deflection of a non-uniform stream, no net trailing vorticity is set up in the exit flow and hence there is no secondary motion.In the case of an impulse cascade of finite dimensions with constant turning, it is found that the trailing vorticity has three distinct components—the passage vorticity and two components which appear as vortex sheets springing from the trailing edges of the aerofoils. It is shown that for small angles of deflection there is no net circulation associated with the trailing vorticity downstream, of the cascade, and it is inferred that this should still be so for large deflections.

scholarly journals A New and Simple Method to Capture Small Arboreal Mammals: The Suspended Pitfall

2019 ◽  
Vol 20 (1) ◽  
pp. 1-14
Author(s):  
Helder José ◽  
Iasmin Macedo ◽  
Mateus Cruz Loss
Keyword(s):  
The Other ◽  
Southeastern Brazil ◽  
Native Forest ◽  
Simple Method ◽  
Live Trap ◽  
Set Up ◽  
Cacao Plantation ◽  
Didelphis Aurita ◽  
Tree Branch ◽  
Doce River

The suspended pitfall demonstrates a new and simple mechanism to capture small arboreal and scansorial mammals. It is an arboreal version of the pitfalls traditionally used to capture terrestrial amphibians and reptiles. Buckets with bait inside are raised by a rope until they reach a tree branch at the desired height. Tests were performed in the Atlantic Forest at three different sites at the mouth of Doce River in Linhares, southeastern Brazil. In one of them suspended pitfalls were set up in the understory of a shaded cacao plantation (cabruca agroforest) in the branches of cacao trees between 2 and 3 m in height, and in the other they were placed in a native forest between 5 to 15 m in height. At the third site, suspended pitfalls were tested together with the other live traps used hitherto in the understory of other cabruca agroforest. The marsupials Didelphis aurita, Caluromys philander, Marmosa (Micoureus) paraguayana, Gracilinanus microtarsus, Marmosa murina and the rodent Rhipidomys mastacalis were captured by suspended pitfall. This live trap was capable of catching all sizes of small arboreal mammals, including juvenile individuals. This method proved to be functional for the capture of some small arboreal mammals and may be a complementary alternative for sampling in high forest strata.

Absolute polarimeter for the proton-beam energy of 200 MeV

2013 ◽  
Vol 76 (12) ◽  
pp. 1490-1496
Author(s):  
A. N. Zelenski ◽  
G. Atoian ◽  
A. A. Bogdanov ◽  
S. B. Nurushev ◽  
F. S. Pylaev ◽  
...  
Keyword(s):  
Proton Beam ◽  
Beam Energy ◽  
Proton Beam Energy

Pump Performance Improvement by Restraining Back Flow in Screw-Type Centrifugal Pump

2005 ◽  
Author(s):  
Yasushi Tatebayashi ◽  
Kazuhiro Tanaka ◽  
Toshio Kobayashi
Keyword(s):  
Pressure Fluctuations ◽  
Centrifugal Pumps ◽  
Two Phase ◽  
Simple Method ◽  
Back Flow ◽  
Pump Performance ◽  
Impeller Outlet ◽  
Pump Head ◽  
The Difference ◽  
Set Up

The authors have been investigating the various characteristics of screw-type centrifugal pumps, such as pressure fluctuations in impellers, flow patterns in volute casings, and pump performance in air-water two-phase flow conditions. During these investigations, numerical results of our investigations made it clear that three back flow regions existed in this type of pump. Among these, the back flow from the volute casing toward the impeller outlet was the most influential on the pump performance. Thus the most important factor to achieve higher pump performance was to reduce the influence of this back flow. One simple method was proposed to obtain the restraint of back flow and so as to improve the pump performance. This method was to set up a Ring-like wall at the suction cover casing between the impeller outlet and the volute casing. Its effects on the flow pattern and the pump performance have been discussed and clarified to compare the calculated results with experimental results done under two conditions — namely, one with and one without this Ring-type wall. The influence of wall’s height on the pump head was investigated by numerical simulations. In addition, the difference due to the wall’s effect was clarified to compare its effects on two kinds of volute casing. From the results obtained it can be said that restraining the back flow of such pumps was very important to achieve higher pump performance. Furthermore, another method was suggested to restrain back-flow effectively. This method was to attach a wall at the trailing edge of impeller. This method was very useful for avoiding the congestion of solids because this wall was smaller than that used in the first method. The influence of these factors on the pump performance was also discussed by comparing simulated calculations with actual experiments.

scholarly journals Dielectric-Filled Reentrant Cavity Resonator as a Low-Intensity Proton Beam Diagnostic

Instruments ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 24 ◽  
Author(s):  
Sudharsan Srinivasan ◽  
Pierre-André Duperrex
Keyword(s):  
Resonance Frequency ◽  
Proton Beam ◽  
Second Harmonic ◽  
Cavity Resonator ◽  
Beam Current ◽  
Dielectric Thickness ◽  
Medical Treatment Facility ◽  
Beam Currents ◽  
Paul Scherrer ◽  
Non Destructive

Measurement of the proton beam current (0.1–40 nA) at the medical treatment facility PROSCAN at the Paul Scherrer Institut (PSI) is performed with ionization chambers. To mitigate the scattering issues and to preserve the quality of the beam delivered to the patients, a non-interceptive monitor based on the principle of a reentrant cavity resonator has been built. The resonator with a fundamental resonance frequency of 145.7 MHz was matched to the second harmonic of the pulse repetition rate (72.85 MHz) of the beam extracted from the cyclotron. This was realized with the help of ANSYS HFSS (High Frequency Structural Simulator) for network analysis. Both, the pickup position and dielectric thickness were optimized. The prototype was characterized with a stand-alone test bench. There is good agreement between the simulated and measured parameters. The observed deviation in the resonance frequency is attributed to the frequency dependent dielectric loss tangent. Hence, the dielectric had to be resized to tune the resonator to the design resonance frequency. The measured sensitivity performances were in agreement with the expectations. We conclude that the dielectric reentrant cavity resonator is a promising candidate for measuring low proton beam currents in a non-destructive manner.

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