Radiation Protection Instructions for Test Beam User

1. Radiation Protection Instructions for Test Beam User • Introduction • At DESY • Personal Dosimeter • Radiation Protection Areas • Prohibited Areas • Controlled Areas • Switching on .. • Controled access (Accelerator/Test Beam) • Search (Test Beam Area) • Radioactive materials/probes Norbert Meyners, MEA

2. Introduction Radioactivity is dangerous. • There are deterministic (killing) effects at high doses (~1 Gy=1joule/kg=100rad) • lethal dose (for single whole body exposure) 4-5 Sv • and stochastic effects at lower doses (Absorbed Dose = absorbed energy per mass). • Stochastic effects are still under discussion. • Different types of radiation are more or less dangerous. Equivalent Dose (for biological damage) = absorbed dose x wR(biological factor) wR = 1 (, e, ), wR = 5 – 20 (p, n, );unit: 1Sv (Sievert) = 1joule/kg = 100rem • The legal dose limits for exposures due to work have been reduced in 2001. • legal limit for non-radiation workers 1mSv/year • legal limit for persons of category B 6mSv/year • legal limit for persons of category A 20mSv/year • One anyhow receives an exposure: • natural radiation (North Germany 1-2mSv/year), • traveling (roundtrip flight btw. New York  Frankfurt 0.1 mSv) or • medical measures (CAT scan of lungs or abdomen 5 – 30 mSv) • Laws and regulations (Ger: “Strahlenschutzverordnung”, “Röntgenverordnung”) demand to keep the exposure as small as possible. Norbert Meyners, MEA

3. Radiation Protection Actions Duration of Stay How to keep the exposure as small as possible? Shielding Distance Instruction Norbert Meyners, MEA Interlock System Labelling

4. Radiation SafetyResponsible Person At DESY • Accelerators  • synchrotron radiation (X-rays) • primary beam losses (e-, p-showers) • secondary radiation (g, neutrons) Radiation Protection Group D3 46 Radiation Safety Officer Klystrons &Cavities (X-rays) radioactive sources (a, b, g) activated materials (a, b, g) Norbert Meyners, MEA

5. Personal Dosimeter combination of photon and neutron dosimeter • Photon dosimeter(PLD, photo luminescence dosimeter, Messstelle für Strahlenschutz, HH,Dose >= 0.1 mSv) • Neutron dosimeter(nuclear track emulsion, PSI - Sektion Messwesen, Dosis >= 0.5 mSv) Norbert Meyners, MEA

6. A prohibited area is an area with a possible local dose > 3 mSv/h Labeling: !!! Entry to a prohibited area is strictly forbidden !!! Where are prohibited areas ? All accelerator rooms,when the accelerator is on! All beam areas,when the beam is on! Areas with high rf-power, when power is on! Linac 2converter area, fast passage allowed Some adjacent areas,when the accelerator is on, such as tunnel ceilings at PETRA, DORIS, FLASH Exceptions are labeled in addition: Prohibited Areas interlock system ON / OFF Norbert Meyners, MEA

7. In a controlled area at DESY, a personal dose > 1 mSv per year can be possible Labeling: Exceptions are labeled in addition: Entry is only allowed if: there is a working mission, the personal dosewill be measured and a radiation protection instruction was given to you. Entry is not allowed for: people under 18 years and pregnant and nursing women. In controlled areas it is forbidden to: eat, drink and smoke. Controlled Areas Norbert Meyners, MEA

8. Search (High Responsibility) Start searchIn accelerators: message: „Tunnel search ! Please leave the tunnel !“ Search buttonsforce to reach the farest point Warning Yellow warning lamps on Lights dimmed (Accelerators) Warning message (1min) Example: „Attention: DESY is going to be switched on !“ Prohibited area Beam(possible) Still inside, warning signs on? Upps! Escape Or EmergencyOFF Switching ON an Accelerator or a Beam Norbert Meyners, MEA

9. Controlled Access (Accelerators) (To avoid to search the area again.) • Persons arrive at a yellow door with red lamp on • Contact machine controlroom via phone • Operator reads your DESY ID-card • Each person takes a key • Operator bridges the door contacts • While the red lamp is off,door can be open. Remark: Don’t open doors with a red lamp/tableau onexcept “your own” Norbert Meyners, MEA

10. Close the beam shutter Each personthat enters the interlock area takes a key from the key cabinet 2 keys = max. 2 persons(If the beam shutter is still open one can not take a key!!!) With the keyat the doorbridge the door contacts While the red lamp is off,door can be open. Remark: When the shutter is closed, one can break the test beam area interlock without disturbing the machine. Controlled Access (Test Beam) Norbert Meyners, MEA

11. The responsible persontakes a key from the key cabinet An assistant could take the second one (Exactly 1 key per person!) Start search with the keyat the door(from inside) Press all search buttons (ger: “Absuche”; red boxes) while searching the area!  Emergency Off Buttons (ger: “Notaus”) start to blink. Check that there are no ladders leaning at the walls! Leave the area while bridging the door contacts with the master key at the door (as descript in slide “Controlled Access”)! Search (Test Beam Area) Norbert Meyners, MEA

12. Radioactive materials/probes • All radioactive material that comes to DESY has to be reported to radiation safety group (D3) ! ! ! • Have to be labeled: • Wear your dosimeter, if needed • Wash your hands afterwards • Store theft protected (Safe in the test beam hut) • Waste disposal via D3 • Ask D3 before shipping, mechanical processing etc.. Be aware that components near the accelerator beam lines may be radioactive !!! D3 will measure the fields! D3-Homepagewww.desy.de/d3/d3indexe.html Norbert Meyners, MEA