NOVA Medium Energy Target ME-1 autopsy procedure and … · 2018-08-03 · 4. Target autopsy tools and equipment 8/3/2018 V.Sidorov/ NOVA Medium energy ME-1 Target autopsy procedure

Vladimir SidorovInput: J. Hylen Fermilab7 High Power Targetry Workshop5 June 2018

NOVA Medium Energy Target ME-1 autopsy procedure and equipment

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1. Target operating conditions and history

2. Purpose and Scope

3. Target autopsy facility

4. Target autopsy tools and equipment

5. Target autopsy procedure5.1 Target delivery ,installation and alignment5.2 Downstream flange removal5.3 Cameras trolley insertion5.4 Graphite fins observation

6. Graphite chip removal

7. Conclusions

Contents

NuMI-NOVA target MET-01 first saw beam on 9/2/2013, and last beam to the target was on 7/29/2016. It took 1.116 x1021 Protons at 120 GeV/Proton during that time. Proton beam spot size varied, mostly between 1.1 mm RMS and 1.3 mm RMS.Beam power was initially around 300 kW and increased to around 540 kW during the last half-year.


The target can developed a helium leak where the downstream beryllium window is e-beam welded to the aluminum flange. The leak was big enough to be seen starting on May 26, 2016.

The target was run with increasing helium leak rate until it reached about 7 liters per minute after about two weeks.

The flow was then limited to 7 liters per minute, and the pressure allowed to gradually decrease during the rest of the run, being at somewhere around a couple tenths to half a psi at the end.

Beam power during operation of MET-01.

1.Target operating conditions and history J. Hylen

2. Purpose and Scope


The purpose of this ME-1 Target autopsy phase is to investigate the condition of the target graphite fins. To observe the graphite fins, the downstream flange has to be removed. The Screw driver tool accesses the flange via the remote positioning fixture and is operated remotely by drive mechanisms and the through-wall manipulator.

DownstreamFlange

Graphite fins

3. Target autopsy facility


The ME Target is installed inside the C-0 Work cell in the front of the lead glass window and aligned with the special fixture equipped with the screw driver tool. The fixture has X-Y-Z directions movements and reachable by tele-manipulators.A mock-up target was constructed and steps practiced before starting the autopsy with the actual target.

Tele-manipulator

Fixture

Target support standTarget mock-up

Hand wrench

CaskWork cell door

Lead glass window

Tele-manipulator

Videocenter

Motors control

4. Target autopsy tools and equipment


The special Screw driver tool is designed and fabricated for this ME target autopsy. The tool is mounted on the existing remote positioning fixture inside the C-0 Work Cell. Two cameras are attached to the trolley that is inserted into the target canister for the both sides of the target fins observation. The trolley is equipped with lights . The six feet aluminum tubes with the tele-manipulator holder provides cameras delivery to the upstream end of the target.

Screw driver tool

Trolley

Camera Light

Screw driver tool Flange holder Flange support

Trolley-tubeassembly

5. Target autopsy procedure


Delivery target into the Work cell. Pick up target by crane and placed on the support stands.Align target with screw driver tool.

5.1 Target delivery installation and alignment

TargetScrew drivertool

Target

Cask

Target DS Flange

Target cart

Unscrew nine top flange screws and install flange holding bracket. Hold it with the manipulator. Unscrew all others flange screws. Moved the fixture cart with screw driver out from target. The flange is loosened from the gasket by second manipulator and placed into the support stand located in the plastic pan.


5.2 Downstream flange removal

Flange support stand Flange

Flange holder

Tele-manipulatorjaw

First the target was observed with a wall mounted camera. The cameras cart is picked up by manipulator and installed into the target canister. Cameras are moved slowly into the target canister till the upstream end of the target.


5.3 Cameras trolley insertion

Target downstream end

Target upstream end

Trolley

Graphite chip


5.4 Graphite fins observation

Target upstream end

Target downstream end

All 50 fins of the target graphite at beam level looks in very good condition.There was discoloration of the fins that appears to follow the hottest areas on the fins; not much on the fins near upstream and downstream end, and large areas on fins near shower maximum.

Shower maximum

Beam


6. Graphite chip removalThe only sign of internal damage is a chip that is believed to have come off the bottom of a fin. The bottoms of the fins are notched to set height of fin, and the notch can create a weaker point.

Example fin (un-used because it cracked before installation) to show notch.

Chip removingbracket

Gluetape

Graphite chip

7. Conclusions

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1. No visible radiation damage to target graphite ; Monte Carlo based estimate of about 1.1 DPA at peak.

2. The target can be used as a spare target with new downstream end flange.


Target autopsy team

Jim HylenTarget autopsy coordinator and maker of physics-based decisions

Vladimir SidorovEngineer, tools and equipment constructor

Cervando CastroOperator of remote tele-manipulators and crane

Mike CoburnOperator of tools motionsystems

Robert AlbrechtOperator of video recorderand second tele-manipulatoroperator

Keith AndersonVideo systemconstructor

Jim ZahuronesOperator of video recorder

Ralph FordTarget mock-upassembly

Tony BuschRadiation safety oversight

Documents

NOVA Medium Energy Target ME-1 autopsy procedure and … · 2018-08-03 · 4. Target autopsy tools and equipment 8/3/2018 V.Sidorov/ NOVA Medium energy ME-1 Target autopsy procedure