Development of Positron Microbeam in AIST

Oshima, Nobuyuki; Suzuki, Ryoichi; Ohdaira, Toshiyuki; Kinomura, A.; Narumi, T.; Uedono, Akira; Fujinami, Masanori

doi:10.4028/www.scientific.net/msf.607.238

Cited by 17 publications

(13 citation statements)

References 11 publications

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“…The last step is to develop the focus system of the slow positron beam. The beam should be focused into 100 nm while it can currently be focused only into 25 µm [28] by different technique. The detection of the transition to BEC will also be possible by the same technique as the precise measurement of the Ps thermalization.…”

Section: The Roadmap For Ps Becmentioning

confidence: 99%

Study on cooling of positronium for Bose–Einstein condensation

Shu¹,

Fan²,

Yamazaki³

et al. 2016

J. Phys. B: At. Mol. Opt. Phys.

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A new method of cooling positronium down is proposed to realize Bose-Einstein condensation of positronium. We perform detail studies about three processes (1) thermalization processes between positronium and silica walls of a cavity, (2) Ps -Ps scatterings and (3) Laser cooling. The thermalization process is shown to be not sufficient for BEC. Ps -Ps collision is also shown to make a big effect on the cooling performance. We combine both methods and establish an efficient cooling for BEC. We also propose a new optical laser system for the cooling.

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Section: The Roadmap For Ps Becmentioning

confidence: 99%

Study on cooling of positronium for Bose–Einstein condensation

Shu¹,

Fan²,

Yamazaki³

et al. 2016

J. Phys. B: At. Mol. Opt. Phys.

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“…The lifetime and intensity of o-Ps in EB exposed positive tone non-CA and CA resists were measured using PPMA (beam diameter：~ 10 mm, time resolution (FWHM)：~280 ps, vacuum： ~ 1E-5 Pa) installed at AIST [15][16][17] , as shown in Fig.1. Figure 2 shows the penetration depth profile of positron with an energy of 1.0 keV.…”

Section: Free-volumementioning

confidence: 99%

Evaluation of vacancies in positive-tone non-chemically and chemically amplified EUV / EB resists: relationship between free-volume and LER

et al. 2014

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EUV, X-ray and EB mainly induce ionization in resist materials and its energy deposition process is different from ArF exposure. Linear energy transfer (LET) effect for resist sensitivity is very important issue from the viewpoint of radiation induced chemical reactions for high-volume nanofabrication. Therefore the knowledgebase of radiation chemistry is required for understanding the resist performances for EUV lithography. In order to acquire the knowledge of resist materials for EUV / EB lithography from a viewpoint of the free-volume, the positron annihilation lifetime spectroscopy was carried out using positron probe microanalyzer (PPMA) installed at AIST. The size of free-volume can be evaluated from the lifetime of ortho-Positronium (o-Ps). The lifetime and intensity of o-Ps in EB-exposed positive-tone non-chemically amplified (non-CA, ZEP) and CA (UV-III) EUV / EB resists were observed. Moreover, to evaluate the relationship between line edge roughness (LER) and free-volume, EB lithography was carried out, and then sensitivities (E0 and Esize) and LER were measured. For both non-CA and CA resist materials, the changes of free-volume due to evaporation of outgas, polarity change or chain scission would hardly influence on their LER and resolution.

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“…The beam is accelerated to a desired energy by acceleration tube electrodes and focused by a magnetic lens near the sample. The spot size of the positron beam on the sample was measured to be 30-100 mm by a knife edge method (Oshima et al, , 2009). …”

Section: Generation Of a Linac-based Positron Microbeammentioning

confidence: 99%

“…A method for focusing a LINAC-based intense positron beam was developed in AIST and a microbeam with diameter of E30 mm was obtained (Oshima et al, 2009). The microbeam can be pulsed with two different kinds of pulsing system to measure positron lifetime.…”

Section: Introductionmentioning

confidence: 99%