title: Note: Neutron shutter for Kolkata superconducting cyclotron.
abstract: In particle accelerator facilities, experimental areas are isolated from active accelerator area with thick concrete walls. A neutron shutter is used to isolate the experimental areas from the active accelerator area in the beam line. These shutters are provided primarily to reduce the secondary radiations like neutrons in the experimental areas to permissible limit when the primary beam is blocked in the accelerator area. The reduced radiation level in the experimental areas makes the experimental areas accessible. The shutters should allow the primary beam to pass to the experimental caves when they retracted from the beam line. A new neutron shutter has been designed and fabricated. This shutter incorporates compact features with considerable reduction in length, surface area and volume. The attenuation of secondary radiations is evaluated using Monte-Carlo radiation transport code FLUKA. It is found that the features of the shutter are sufficiently good enough to reduce the diffused secondary radiations well within the permissible levels.
authors.affiliation: Mechanical Engineering Group, Variable Energy Cyclotron Centre, I∕AF Bidhan Nagar, Kolkata 700064, India. gautam@vecc.gov.in
authors.forename: Gautam
authors.initials: G
authors.lastname: Pal
authors.forename: Tapas
authors.initials: T
authors.lastname: Bandopadhyay
authors.forename: Chinmay
authors.initials: C
authors.lastname: Nandi
authors.forename: Sujoy
authors.initials: S
authors.lastname: Chatterjee
authors.forename: R
authors.initials: R
authors.lastname: Ravishankar
authors.forename: Sumantra
authors.initials: S
authors.lastname: Bhattacharya
authors.forename: Mausumi Sengupta
authors.initials: MS
authors.lastname: Mitra
authors.forename: Javed
authors.initials: J
authors.lastname: Akhter
authors.forename: Santosh
authors.initials: S
authors.lastname: Mishra