safety using fluorine eximer lasers jack j. hahn slac

Safety Using Safety Using Fluorine Eximer Fluorine Eximer

Lasers Lasers Jack J. Hahn SLACJack J. Hahn SLAC

Purpose of Today’s TalkPurpose of Today’s Talk Background on fluorine gas (F2) in Background on fluorine gas (F2) in

Eximer Lasers at SLACEximer Lasers at SLAC Review hazards of F2 gas Review hazards of F2 gas Worst case accident scenarios Worst case accident scenarios SLAC ES&H Guideline “Safety Using SLAC ES&H Guideline “Safety Using

Fluorine Eximer Lasers”Fluorine Eximer Lasers” Equipment design approaches to minimize Equipment design approaches to minimize

the hazards of F2 in Eximer Lasersthe hazards of F2 in Eximer Lasers Not covering laser beam/electrical other Not covering laser beam/electrical other

hazardshazards

Background on use of Background on use of Fluorine in Eximer Lasers Fluorine in Eximer Lasers

at SLACat SLAC Final Focus Test Beam (FFTB)- Final Focus Test Beam (FFTB)-

GAM, Historical UsageGAM, Historical Usage Fringe patterns to measure beam Fringe patterns to measure beam

locationlocation

Klystron Test Laboratory- Lambda Klystron Test Laboratory- Lambda Physik Physik Laser beams to make plasma deposited Laser beams to make plasma deposited

oxide cathodesoxide cathodes

Final Focus Test Beam

Klystron Test Lab Laser

What is a Fluorine What is a Fluorine Eximer Laser?Eximer Laser?

Uses “Uses “ExExcited Dcited Dimerimer” lasing ” lasing mediummedium

Excited diatomic molecule- Inert Excited diatomic molecule- Inert gas/halogengas/halogen

Halogen is FluorineHalogen is Fluorine

Some Hazards of Pure Some Hazards of Pure Fluorine GasFluorine Gas

Reacts violently and decomposes to Reacts violently and decomposes to hydrofluoric acid (HF) with moisturehydrofluoric acid (HF) with moisture

Fire fighting- Fires with fluorine as Fire fighting- Fires with fluorine as oxidizer only extinguished by oxidizer only extinguished by shutting off source of fluorine. Water, shutting off source of fluorine. Water, CO2 add fuel to fireCO2 add fuel to fire

Immediately dangerous to life and Immediately dangerous to life and health (IDLH) = 25ppmhealth (IDLH) = 25ppm

Forms of Fluorine UsedForms of Fluorine Used

FFTB GAM FFTB GAM 1700 ppm premix of F21700 ppm premix of F2 5% F2 Passivating Gas5% F2 Passivating Gas

Lambda PhysikLambda Physik Pure F2 generated where neededPure F2 generated where needed

Worst Case Accident Worst Case Accident ScenariosScenarios

Whole-bottle 5% F2 passivating gas Whole-bottle 5% F2 passivating gas release in FFTBrelease in FFTB

300 yard FFTB area- 3 times FFTB area 300 yard FFTB area- 3 times FFTB area is affected > IDLH. Unacceptable, is affected > IDLH. Unacceptable, required mitigation. (credit to Joe required mitigation. (credit to Joe Kenny/Ih Lin for these calculations)Kenny/Ih Lin for these calculations)

SLAC ES&H Guideline SLAC ES&H Guideline “Safety Using Fluorine “Safety Using Fluorine

Eximer Lasers”Eximer Lasers” Networking from International HEP Networking from International HEP

Safety ForumSafety Forum

Charles (Bill) Nuttall (CERN retired); Charles (Bill) Nuttall (CERN retired); Joe Kenny, Dr Maria Gherman, John Joe Kenny, Dr Maria Gherman, John ShepardsonShepardson

Hazardous Experimental Equipment Hazardous Experimental Equipment Committee (HEEC) all of SLAC Committee (HEEC) all of SLAC

SLAC ES&H Guideline SLAC ES&H Guideline (cont.)(cont.)

Other influencesOther influences Santa Clara County Toxic Gas OrdinanceSanta Clara County Toxic Gas Ordinance

http://www.ehinfo.org/content/0,4745,sid%253D113http://www.ehinfo.org/content/0,4745,sid%253D11383%2526chid%253D15213%2526ccid%253D336101,83%2526chid%253D15213%2526ccid%253D336101,00.html#TGO00.html#TGO

Not required to follow the Toxic Gas Not required to follow the Toxic Gas Ordinance (TGO)Ordinance (TGO)

Not in county’s jurisdictionNot in county’s jurisdiction Designed for large quantity Silicon Valley high-tech Designed for large quantity Silicon Valley high-tech

manufacturingmanufacturing Below the triggers for the TGOBelow the triggers for the TGO


Devices reviewed by HEEC, Devices reviewed by HEEC, guidelines provide resource for guidelines provide resource for reviewersreviewers

Proposals use guideline or be able to Proposals use guideline or be able to justify deviations justify deviations


Engineering ControlsEngineering Controls Flow-restricting orifices to limit material Flow-restricting orifices to limit material

releasedreleased Keep gas cylinders in a gas cabinets or Keep gas cylinders in a gas cabinets or

well ventilated exterior locationwell ventilated exterior location Small door for adjusting the regulatorSmall door for adjusting the regulator Large door for changing tanksLarge door for changing tanks

Ventilate the outside of the area Ventilate the outside of the area surrounding the gas cylinder and laser surrounding the gas cylinder and laser cabinet that contains laser chamber.cabinet that contains laser chamber.

Monitor ventilation with alarmMonitor ventilation with alarm


Engineering ControlsEngineering Controls

Establish location and design to protect Establish location and design to protect gas systems from physical damagegas systems from physical damage

Out of path of heavy equipmentOut of path of heavy equipment

Design system to survive earthquakeDesign system to survive earthquake


Engineering Controls (cont.)Engineering Controls (cont.) Accessible gas system fittings- physical Accessible gas system fittings- physical

barrier to impede inadvertent loosening barrier to impede inadvertent loosening of fittingsof fittings

Eliminate fittings entirely if possibleEliminate fittings entirely if possible

Due to reactivity of F2, take extreme care Due to reactivity of F2, take extreme care in manipulation and choice of materialsin manipulation and choice of materials


Administrative Procedures and SignsAdministrative Procedures and Signs Post “Danger” signsPost “Danger” signs Alert Fire DepartmentAlert Fire Department

Provide FD TourProvide FD Tour Turn off bottles when not in useTurn off bottles when not in use In event of gas system failure evacuate In event of gas system failure evacuate

immediatelyimmediately Turn off cylinders and regulators only if safe Turn off cylinders and regulators only if safe

to do so without protective equipmentto do so without protective equipment


Administrative Procedures and Signs Administrative Procedures and Signs (cont.)(cont.)

Two people minimum working on toxic gas Two people minimum working on toxic gas systemssystems

Special precautions may be needed when Special precautions may be needed when using passivating gasesusing passivating gases

Evacuating excess staff from an effected areaEvacuating excess staff from an effected area Provide Safety or Security personnel to control Provide Safety or Security personnel to control

area entryarea entry

SLAC ES&H Guideline SLAC ES&H Guideline (cont.) (cont.)

Personal Protective Equipment Personal Protective Equipment (PPE) for Fluorine Use(PPE) for Fluorine Use

Gas proof goggles (unventilated)Gas proof goggles (unventilated)

Neoprene glovesNeoprene gloves


First AidFirst Aid Eyewash located nearby but outside of Eyewash located nearby but outside of

potential exposure areapotential exposure area

Calcium gluconate gel for use on skin- Calcium gluconate gel for use on skin- near the eyewashnear the eyewash Used to minimize additional damage from Used to minimize additional damage from

the HFthe HF

Equipment Design to Minimize Equipment Design to Minimize the Hazards of F2 Use with the Hazards of F2 Use with

Eximer LasersEximer Lasers

Most problematic issue- Fluorine gas Most problematic issue- Fluorine gas cylinderscylinders

Passivating gas – Higher concentration Passivating gas – Higher concentration

Premix operating gasPremix operating gas

Solution- Eliminate F2 gas cylinders Solution- Eliminate F2 gas cylinders through in situ ( in-place) generation of F2through in situ ( in-place) generation of F2

Equipment Design Equipment Design Approaches (cont.)Approaches (cont.)

Generate F2 gas in-placeGenerate F2 gas in-place

Heat fluorine containing salt to Heat fluorine containing salt to generate F2 gasgenerate F2 gas

Klystron Lab Lambda Physik- In-place Klystron Lab Lambda Physik- In-place

HaloSafe™ Unit F2 Generator

Lambda Physik

Krypton Gas (inert)


Some Lambda Physik Additional Some Lambda Physik Additional Safety Features Safety Features

F2 sources generate only the amount of F2 sources generate only the amount of gas needed for the laser filling cyclegas needed for the laser filling cycle

F2 is kept under negative pressureF2 is kept under negative pressure

F2 filter eliminates the F2 when not in useF2 filter eliminates the F2 when not in use


Advice Advice Buy the right equipment- In-place F2 Buy the right equipment- In-place F2

generationgeneration

Reports suggest that there are older Reports suggest that there are older generation systems available for “free”generation systems available for “free”

May want to consider total costs and safety May want to consider total costs and safety aspects of these systems aspects of these systems

More InformationMore Information

Safety Using Fluorine Eximer Lasers Safety Using Fluorine Eximer Lasers http://www-group.slac.stanford.edu/esh/guidelines/fluorhttp://www-group.slac.stanford.edu/esh/guidelines/fluor

inelaser.pdfinelaser.pdf

Santa Clara County Toxic Gas OrdinanceSanta Clara County Toxic Gas Ordinance http://www.ehinfo.org/content/0,4745,sid%253D11383http://www.ehinfo.org/content/0,4745,sid%253D11383

%2526chid%253D15213%2526ccid%253D336101,00.ht%2526chid%253D15213%2526ccid%253D336101,00.html#TGOml#TGO

Toxic Gas Ordinance at Stanford Toxic Gas Ordinance at Stanford http://www.stanford.edu/dept/EHS/prod/researchlab/labhttp://www.stanford.edu/dept/EHS/prod/researchlab/lab

/tgo//tgo/

Lambda Physik- Information on Halosafe systemsLambda Physik- Information on Halosafe systems http://www.lambdaphysik.com/script/content.asp?http://www.lambdaphysik.com/script/content.asp?

area=products&sitepages_id=47area=products&sitepages_id=47

safety using fluorine eximer lasers jack j. hahn slac

Documents