PAUL SCHERRER INSTITUT CERN / Oct. 17. 2005 / P.A.Schmelzbach

PAUL SCHERRER INSTITUT

CERN / Oct. 17. 2005 / P.A.Schmelzbach



PSI Experience, Dealing with a MW Beam…Pierre A. Schmelzbach

…in Switzerland



COCKCROFT-WALTON

INJECTOR 2870 keV TRANSFER LINE

72 MeV TRANSFER LINE

590 MeV CYCLOTRON

TARGET E

TARGET M

SINQ TRANSFER LINE SINQ

OVERVIEW

Protonentherapie (+ 2006) UCN (in construction)

IP

3 mA /1.8 MW

2 mA /1.2 MW

2 mA /1.1 MW

1.4 mA /.8 MW



Basic Considerations for Design and Operation

Accelerators: Cyclotrons with large turn separation at the extraction

Losses: Extraction from Injector Cyclotron, injection and extractionfrom Ring Cyclotron: < 0.5 A each

Beam lines: < 1nA / m

Local shielding

Remote handling

Repairs in hot cell located in machine / experimental hall



Beam production on target E

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

1974

1975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

year

char

ge

del

iver

ed [

mA

h]

ho

urs

of

pro

du

ctio

n [

h]

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

aver

age

curr

ent

[mA

]

delivered charge on target E hours of production average delivered current

Rebuilding of Target E /

Beam Dump



TARGET E

TARGET WHEEL

ABSORBERS

COLLIMATOR K1

COLLIMATORS K2 + K3



Layout of the beam line between target E and beam dump

TARGET-E INSERT

COLLIMATORS DIAGNOSTIC INSERTS

MOVABLE SLITS

BEAM DUMP

INFLATABLE SEAL ASSEMBLY

WORKING PLATFORM

CONCRETE SHIELDING



Special tools

• Shielded flasks for transportation to hot cell

• Remote control of main functions (e.g. lifting defective component out of beam line shielding)



Accelerator & Beam Line Protection

• Range of 590 MeV p in steel is 28 cm = welding torch !

• The Run Permit System has to switch off the beam in less than 5 ms in order to avoid burning a hole in a vacuum chamber

• Transmission

• Halo

• Losses (Ioniz. Chambers)



We are not alone !

Swiss Authorities:BAG / OFSP (Swiss Federal Office of Public Health)HSK / DPSIN (Swiss Nuclear Safety Inspectorate)NAGRA (National Cooperative for the Disposal of Nuclear Waste)

Burocracy- before- during- after



eventually….

+ some others…



1. Gen. description of the facility / use

2. Plan of controlled areas

3. Machine protection systems

4. Regulations RA-protection (site)

5. Regulations RA-protection (Control Room)

6. Operating regulations for personnel RA-protection systems

7. Concept personnel RA-protection systems (access control vaults)

8. Operating regulations accelerator

• Responsabilities

• Operation, emergencies,…

9. Access regulations to site

10. Quartely reports (Doses)

Further authorizations needed for• Release of radioactivity• Hot cell operation• Special user‘s facilities

Basis for the authorizationto operate the PSI proton facility



The good old times . . . Things become tougher !

Experience with the high current accelerator

• Start of the project was quite easy, first upgrade (<1.5 mA) also

• Upgrade 1.5 to 2 mA - only short test periods at higher current allowed first- delay >2 years because a long pending condition was not fulfilled ( controlled access to site [RA check of persons, vehicles])

• Enhanced requirements on facilities for selective storage of material (be carefull with vocabulary and definitions)

• History, tracking of RA material (waste), e.g. ISRAM, specifications for waste / waste containers (HSK, NAGRA)

• Also: BAG frequent visits (about once a month), presentation of shutdown planning



Experience with the installation of our new 250 MeV, 500 nA cyclotron (PROSCAN Project)

BAG want:

• to be involved at a early stage (before you start to build something) submit plans and safety report early • to supervise step by step the commissioning of the systems several requests for “authorization to operate xxxx” + progress reports

Looks also at things that are not their immediate business (e.g. rf-systems)



Recommendations:(to solve a 3-dimensional problem: technology, law, psychology)

• Invite BAG to a first, general information on the project (Dr. Nicolas Stritt ?)

• Define the scope of the project (accelerator only, target a.s.o as separate projects).

• Feel what they want to have in the safety report (can be discussed !, they are reasonable people). Problem with “arbitrary” requirements.

• Safety report: present solutions that satisfy their standards ( not too little, but also not too much !).

• Operating regulations: clear information on who is responsible for what. They accept local rules if equivalent to their standards.

• They read safety report and operating regulations very carefully



4 MWGood Luck !

Documents

PAUL SCHERRER INSTITUT CERN / Oct. 17. 2005 / P.A.Schmelzbach