Response of multiwire proportional counter for energy loss measurement

Kohno, Toshiyuki; Kiyota, Takashige; Matsufuji, Naruhiro; Futami, Yasuyuki; Kanai, Tatsuaki

doi:10.1016/s0168-9002(00)00267-9

Cited by 6 publications

(3 citation statements)

References 10 publications

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“…When using these gases, more than 50% of the gain dropping between the anode wires from the gain on the wire was found by scanning the entire sensitive area with well-collimated 241 Am α-particles. A mixture of Ar/CH 4 (90:10) (P-10) showed the most uniform gas multiplication (better than 1.2% of uniformity over the centre region) among several other easily obtained gases (methane-and propane-based TE gases, CH 4 , N 2 , CO 2 , He/C 4 H 10 (99:1) (Q-gas), He, Ar and Kr) (Kohno et al 2000).…”

Section: Counter For Let Measurementmentioning

confidence: 99%

Influence of fragment reaction of relativistic heavy charged particles on heavy-ion radiotherapy

Matsufuji¹,

Fukumura²,

Komori³

et al. 2003

Phys. Med. Biol.

142

118

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The production of projectile fragments is one of the most important, but not yet perfectly understood, problems to be considered when planning for the utilization of high-energy heavy charged particles for radiotherapy. This paper reports our investigation of the fragments' fluence and linear energy transfer (LET) spectra produced from various incident ions using an experimental approach to reveal these physical qualities of the beams. Polymethyl methacrylate, as a substitute for the human body, was used as a target. A deltaE-E counter telescope with a plastic scintillator and a BGO scintillator made it possible to identify the species of fragments based on differences of various elements. By combining a gas-flow proportional counter with a counter telescope system, LET spectra as well as fluence spectra of the fragments were derived for each element down from the primary particles to hydrogen. Among them, the information on hydrogen and helium fragments was derived for the first time. The result revealed that the number of light fragments, such as hydrogen and helium, became larger than the number of primaries in the vicinity of the range end. However, the greater part of the dose delivered to a cell was still governed by the primaries. The calculated result of a simulation used for heavy-ion radiotherapy indicated room for improving the reaction model.

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Section: Counter For Let Measurementmentioning

confidence: 99%

Influence of fragment reaction of relativistic heavy charged particles on heavy-ion radiotherapy

Matsufuji¹,

Fukumura²,

Komori³

et al. 2003

Phys. Med. Biol.

142

118

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show abstract

“…The experimental setup is shown in figure 2, where the key detector in this experiment was a LET counter. The LET counter is a gas-flowing-type multi-wire parallel-plate proportional chamber and was developed to simulate experimentally the energy deposited by particles in lengths as small as 5 µm in soft tissue (Kohno et al 2000). The sensitive volume of the counter is a rectangular cavity of 50 mm in width and height and 5 mm in thickness.…”

Section: Let Countermentioning

confidence: 99%

“…The entrance and exit windows are made of aluminized Mylar films of 0.9 mg cm −2 in thickness, and −830 V high voltage is applied to both the windows to act as the cathode plates. The working gas of the LET counter is P-10 gas (Ar:CH 4 = 90:10), which has shown the best uniformity of response over the sensitive area and the best signal-to-noise ratio among tissue equivalent gases (Kohno et al 2000). In this experiment, the P-10 gas was controlled to flow through the LET counter with a reducing valve.…”

Section: Let Countermentioning

confidence: 99%

The LET spectra at different penetration depths along secondary⁹C and¹¹C beams

Li¹,

Komori²,

Kanai³

et al. 2004

Phys. Med. Biol.

Self Cite

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Owing to the potentially therapeutic enhancement of delayed particles in treating malignant diseases by radioactive 9C-ion beam, LET spectra at different penetration depths for a 9C beam with 5% momentum spread, produced in the secondary beam line (SBL) at HIMAC, were measured with a multi-wire parallel-plate proportional counter. To compare these LET spectra with those of a therapeutic 12C beam under similar conditions, the 12C beam was replaced with an 11C beam, yielded in the SBL as well and having almost the same range as that of the 9C beam. The LET spectra of the 9C beam and its counterpart, i.e. the 11C beam, at various depths were compared, especially around the Bragg peak regions. The results show that nearby the Bragg peak lower LET components decreased in the LET spectra of the 9C beam while extra components between the LET peak caused by the primary beam and the lower components due to the fragments could be observed. These additional contributions in the LET spectra could be attributed to parts of the emitted particles from the radioactive 9C ions with suitable conditions regarding the LET counter. Integrating these LET spectra in different manners, depth-dose and dose-averaged LET distributions were obtained for the 9C and 11C beams, forming the basic data sets for further studies. In general, the depth-dose distributions of the 9C and 11C beams are comparative, i.e. almost the same peak-to-plateau ratio. The ratio for the 9C beam, however, has room to increase due to the geometric structure limitation of the present detector. The dose-averaged LETs along the beam penetration are always lower for the 9C beam than for the 11C beam except at the falloff region beyond the Bragg peak. Applying the present depth-dose and dose-averaged LET data sets as well as the essential radiobiological parameters obtained with 12C beams previously for HSG cells, an estimate concerning the HSG cell surviving effects along the penetration of the 9C and 11C beams shows that lower survival fractions for the 9C beam at the distal part of the Bragg peak, corresponding to the stopping region of the incoming 9C ions, can be expected when the same entrance dose is given. It is still hard to appreciate the potential of 9C beams in cancer therapy based on the present LET spectrum measurement, but it provides a substantial basis for upcoming radiobiological experiments.

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Study and full simulation of ten different gases on sealed Multi-Wire Proportional Counter (MWPC) by using Garfield and Maxwell codes

Shohani¹,

Golgoun²,

Aminipour³

et al. 2016

Applied Radiation and Isotopes

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Response of multiwire proportional counter for energy loss measurement

Cited by 6 publications

References 10 publications

Influence of fragment reaction of relativistic heavy charged particles on heavy-ion radiotherapy

Influence of fragment reaction of relativistic heavy charged particles on heavy-ion radiotherapy

The LET spectra at different penetration depths along secondary⁹C and¹¹C beams

Study and full simulation of ten different gases on sealed Multi-Wire Proportional Counter (MWPC) by using Garfield and Maxwell codes

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Response of multiwire proportional counter for energy loss measurement

Cited by 6 publications

References 10 publications

Influence of fragment reaction of relativistic heavy charged particles on heavy-ion radiotherapy

Influence of fragment reaction of relativistic heavy charged particles on heavy-ion radiotherapy

The LET spectra at different penetration depths along secondary9C and11C beams

Study and full simulation of ten different gases on sealed Multi-Wire Proportional Counter (MWPC) by using Garfield and Maxwell codes

Contact Info

Product

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About

The LET spectra at different penetration depths along secondary⁹C and¹¹C beams