Title: T-489: Induced Activity and Residual Dose Rates
1T-489 Induced Activity and Residual Dose Rates
- Irradiation Experiment in Endstation A Spring 2007
Johannes Bauer for T-489 experimenters prepared
3/19/2007
2Motivation
- Monte Carlo Simulations for Design of New
Facilities - Simulation of residual activity improved in last
years - Better-controlled experiments needed for
benchmark tests - CERN Involvement
- Four collaborators from CERN
- Two years ago similar experiment at CERN with
hadron beam - SLAC experiment complimentary with electron beam
3Experimental Setup
- Beam
- Primary beam 28.5 GeV at 20 W average (up to 100
W temporarily), 2x109 e-/pulse at 1 to 10
Hz (not exceeding 100 W) - Compatible with PEP2 and BABAR
- Beams delivered to dedicated copper dump
- Need to know absolute beam power to 5
- Equipment
- Use of existing wire scanner 3WS1 and standard
roller screens for beam monitoring and alignment - Use of existing toroids to measure current
- Infrastructure
- Just standard beam delivery
4Samples at Dump
Installation in beam line inside shielding
tunnelof ESA
Regularly controlled access to remove and
replace samples
Measurements of samples in Bldg.24
5Schedule
- Installation
- Official schedule Mon/Tue April 2/3, 2007
(earlier if access to ESA possible) - Beam
- Starting Wed April 4, 2007 for 5 to 7 days
(earlier if beams available)
6Radiation Hazards
- Concrete in ESA
- Already irradiatedT-489 does not add much lt
0.01 mrem/h - Equipment in ESA
- Also very little 0.13 mrem/h
- Dump
- 1 mrem/h at 30 cm distance off dump surface
- 13 mrem/h on contact
- Values for 100 hours cooling time
7Radiation Hazards (cont)
Worst case radiation dose according to
simulation, 4 days, 20 W, 15 min cooling time
contact 30 cm
Dump 2000 mrem/h 130 mrem/h
sample (worst case stainless steel ) 2 mrem/h 0.02 mrem/h
Dumps 30 cm dose rate 70 mrem/h after 30
min cooling time 50 mrem/h after 1 hour
cooling time 20 mrem/h after 10 hours
cooling time
8Radiation Hazards (cont)
Exposure during sample exchange (4 days of 20 W,
15 min cool-down)
Task Dose rate Time Dose
Approaching dump 1 mrem/h 1 minute 0.017 mrem
Exchanging sample 130 mrem/h 20 seconds 0.72 mrem
Leaving dump 1 mrem/h 1 minutes 0.017 mrem
Total 0.76 mrem
Training and rehearsals will be required
Radiological postings and procedures worked out
with RPFO
9Conclusion
- Radiological aspects under controlboth
short-term and long-term - No additional safety hazards (e.g. no earthquake
bracing needed for equipment)