Abstract
Some medical compact cyclotrons have selfshielding to reduce neutron fluxes. Thermal neutron fluxes in an 18-MeV unshielded cyclotron room and in a 16.5- MeV self-shielded cyclotron room were evaluated. In addition, the radioactivities in concrete and metals due to thermal neutrons in the cyclotron rooms for 30 years were calculated of operation such that the sum of the ratio of the nuclide concentration to the nuclide clearance level was equal to 1. The thermal neutron flux from the unshielded cyclotron was approximately 10 2 cm-2 s-1, whereas that from the self-shielded cyclotron was approximately 102 cm-2 s-1. The thermal neutron fluxes for concrete, stainless steel, vessel steel, and aluminum that reached their clearance levels were 9.80 × 104, 2.17 × 103, 1.87 × 104, and 2.41 × 10 5 cm-2 s-1, respectively. The specific activities in the cyclotron room were found to be sufficiently below the clearance level when the self-shield was employed.
| Original language | English |
|---|---|
| Pages (from-to) | 156-165 |
| Number of pages | 10 |
| Journal | Radiological physics and technology |
| Volume | 5 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Jul 1 2012 |
| Externally published | Yes |
Fingerprint
All Science Journal Classification (ASJC) codes
- Radiation
- Physical Therapy, Sports Therapy and Rehabilitation
- Radiology Nuclear Medicine and imaging
Cite this
Comparison of neutron fluxes in an 18-MeV unshielded cyclotron room and a 16.5-MeV self-shielded cyclotron room. / Fujibuchi, Toshioh; Horitsugi, Genki; Yamguchi, Ichiro; Eto, Akihisa; Iwamoto, Yasuo; Obara, Satoshi; Iimori, Takashi; Masuda, Yoshitada; Watanabe, Hiroshi; Hatazawa, Jun.
In: Radiological physics and technology, Vol. 5, No. 2, 01.07.2012, p. 156-165.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Comparison of neutron fluxes in an 18-MeV unshielded cyclotron room and a 16.5-MeV self-shielded cyclotron room
AU - Fujibuchi, Toshioh
AU - Horitsugi, Genki
AU - Yamguchi, Ichiro
AU - Eto, Akihisa
AU - Iwamoto, Yasuo
AU - Obara, Satoshi
AU - Iimori, Takashi
AU - Masuda, Yoshitada
AU - Watanabe, Hiroshi
AU - Hatazawa, Jun
PY - 2012/7/1
Y1 - 2012/7/1
N2 - Some medical compact cyclotrons have selfshielding to reduce neutron fluxes. Thermal neutron fluxes in an 18-MeV unshielded cyclotron room and in a 16.5- MeV self-shielded cyclotron room were evaluated. In addition, the radioactivities in concrete and metals due to thermal neutrons in the cyclotron rooms for 30 years were calculated of operation such that the sum of the ratio of the nuclide concentration to the nuclide clearance level was equal to 1. The thermal neutron flux from the unshielded cyclotron was approximately 10 2 cm-2 s-1, whereas that from the self-shielded cyclotron was approximately 102 cm-2 s-1. The thermal neutron fluxes for concrete, stainless steel, vessel steel, and aluminum that reached their clearance levels were 9.80 × 104, 2.17 × 103, 1.87 × 104, and 2.41 × 10 5 cm-2 s-1, respectively. The specific activities in the cyclotron room were found to be sufficiently below the clearance level when the self-shield was employed.
AB - Some medical compact cyclotrons have selfshielding to reduce neutron fluxes. Thermal neutron fluxes in an 18-MeV unshielded cyclotron room and in a 16.5- MeV self-shielded cyclotron room were evaluated. In addition, the radioactivities in concrete and metals due to thermal neutrons in the cyclotron rooms for 30 years were calculated of operation such that the sum of the ratio of the nuclide concentration to the nuclide clearance level was equal to 1. The thermal neutron flux from the unshielded cyclotron was approximately 10 2 cm-2 s-1, whereas that from the self-shielded cyclotron was approximately 102 cm-2 s-1. The thermal neutron fluxes for concrete, stainless steel, vessel steel, and aluminum that reached their clearance levels were 9.80 × 104, 2.17 × 103, 1.87 × 104, and 2.41 × 10 5 cm-2 s-1, respectively. The specific activities in the cyclotron room were found to be sufficiently below the clearance level when the self-shield was employed.
UR - http://www.scopus.com/inward/record.url?scp=84866415143&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84866415143&partnerID=8YFLogxK
U2 - 10.1007/s12194-012-0149-2
DO - 10.1007/s12194-012-0149-2
M3 - Article
C2 - 22447045
AN - SCOPUS:84866415143
VL - 5
SP - 156
EP - 165
JO - Radiological Physics and Technology
JF - Radiological Physics and Technology
SN - 1865-0333
IS - 2
ER -