BNL - FNAL - LBNL - SLAC

Progress Report on LQ Program Giorgio Ambrosio

Fermilab

Task Leaders:Fred Nobrega (FNAL) – CoilsJesse Schmalzle (BNL) – CoilsPaolo Ferracin (LBNL) – StructureHelene Felice (LBNL) – Instrumentation and QPGuram Chlachidize (FNAL) – Test prep. and test

LARP Collaboration Meeting 13 Port JeffersonNov. 4-6, 2009

2005 The birth of the LQ

…

…

Some years ago … just before CM 4 …

LARP CM13 – BNL – Nov. 4-6, 2009 G. Ambrosio - Long Quadrupole

We need a successful Long Quadrupole by

the end of 2009April 2, 2005April 2, 2005

We need a successful Long Quadrupole by

the end of 2010

G. Ambrosio - Long Quadrupole 3

Long Quadrupole

Main Features:

• Aperture: 90 mm

• magnet length: 3.7 m

Target:

• Gradient: 200+ T/m

Goal:

• Demonstrate Nb3Sn magnet scale up:– Long shell-type coils

– Long shell-based structure (bladder & keys)

1st Long Quad test by the end of 2009

2nd Long Quad test in mid 2010

LQ Design Report available online at:https://plone4.fnal.gov/P1/USLARP/MagnetRD/longquad/LQ_DR.pdf

LQS01 SSL 4.3 K

Current 13.9 kA

Gradient 242 T/m

Peak Field 12.4 T

Stored Energy 473 kJ/m

LQ in LARP R&D

“S”: Shell-based support structure

“C”: Collar-based support structure

LARP CM13 – BNL – Nov. 4-6, 2009 G. Ambrosio - Long Quadrupole

Long MirrorLM023.6 m longNo bore

FNAL Core progr.

From TQS & LRS to LQS

• LQS is based on TQS

and LRS

TQS Modifications:– Added masters

– Added tie-rods for yoke & pad laminations

– Added alignment features for the structure

– Rods closer to coils

– Rods made of SS

– Segmented shell (4)

LQS with dummy Al coils

LQSD: – LQS assembled with Al coils (LBNL)– Shipped, lifted, tilted (LBNL & FNAL)– Tested at liquid nitrogen (FNAL)

6

LQSD cool down

ΔT=150 KΔT=50 K

Magnet top

Magnet bottom

LQ Coil Design & Fabrication

• Fabrication technology:– From 2-in-1 (TQ coils) to single coil fixtures (LQ)

– Mica during heat treatment

– Bridge between lead-end saddle and pole

• Coil design:– LQ coils = long TQ02 coils with gaps to

accommodate different CTE during HT

Cross-section of TQ/LQ coil

250 mceramicandbindersheet

titanium outer pole

titanium inner pole

250 m ceramic and binder sheet

500 m

250 m

250 m

125 mmica sheet

125 mmica sheet

125 m micasheet

Lead End Return End

1 2 3 4 5 6 7 8 9 10

LQ Coils Handling & Shipment

• New tooling for long coil handling and shipment– Handling: strain < 0.05%

– Shipment on rigid mandrel in shipping fixture w shock absorbers (BNL)

Shipping fixture with shock absorbers

Long Quadrupole Overview – G. Ambrosio 9LARP Collab. Mtg 10 – Port Jefferson, Apr. 23-25, 2008

Quench Protection

• Goal: – MIITs < 7.5 Temp ~ 380 K (adiabatic approx)

• Quench protection param. (4.5 K) – conservative hypothesis– Dump resistance: 60 m(extract ~1/3 of the energy; Vleads ~ 800 V)

– 100% heater coverage ( heaters also on the inner layer)

– Detection time: ~5 ms based on TQs with I > 80% ssl

– Heater delay time: 12 ms based on TQs with I > 80% ssl

Very challenging!J in copper = 2900 A/mm2

at 13.9 kA (4.3 K SSL)

Instrumentation

• Voltage taps: 13 IL + 7 OL• Two protection heaters on each layer

– Large ss strip with narrow heating areas• Successfully tested on Long Racetrack

– “Bubbles” may cause coil-heater shorts test at 4.5, and 3.0 K (1.9K at the end)

• Coil strain gauges: 4 IL– Gauges instrumented with wires

• Structure strain gauges:– Shell: 10 (two full bridges each)

– Rods: 4 (two half bridges each)Test at LN of Protection HeatersLARP CM13 – BNL – Nov. 4-6, 2009 G. Ambrosio - Long Quadrupole

G. Ambrosio - Long QuadrupoleDOE Review 09 - FNAL, July 13-14, 2009

Status Summary

• 5+ production coils are ready– Wind & cure (FNAL)– React. & Impr. (BNL & FNAL)– Instrumentation (all 3 labs)– Shipping fixtures (BNL)

• Shell-structure was tested LQSD& LQS01 was assembled (LBNL)

LQS01 ready for test (FNAL)

LQS01 Assembly

• LQS01 assembled and pre-loaded

Strain gauge readings:• on the structure (shell & rods) are on target

• on the coils are lower than expected with large scattering– Seen also in TQS models; partially caused by coil/pads sub-assembly

Should improve at cold G. Ambrosio - Long QuadrupoleLARP CM13 – BNL – Nov. 4-6, 2009

Comparison of measurements and targets

293 K y (MPa) z (MPa)

Shell measured +33 ±8 +3 ±7

Shell computed +34 +6

Pole measured -12 ±11 +14 ±17

Pole computed -49 -14

Rod measured n/a +60 ± 3

Rod computed n/a +63

G. Ambrosio - Long QuadrupoleLARP CM13 – BNL – Nov. 4-6, 2009

Test Preparation

• Quench Detection System with Adaptive Thresholds– To allow using low threshold at high current avoiding trips due to voltage

spikes at low current

– Both DQD and AQD

• Symmetric Coil Grounding– To reduce peak coil-ground voltage

• LQ needs larger dump resistance than TQ magnets (60 vs 30 mOhm)

• Reconfiguration of the Magnet Protection System– Additional Heater-Firing-Units for all LQ heaters (16)

• Modified Strain Gauge Readout System– To reduce noise and sampling time

J in copper = 2900 A/mm2

at 13.9 kA (4.3 K SSL)

All new systems tested all together two weeks ago Upgrades passed LQS01 Test Readiness Review

LQS01 Status

• LQS01 is connected to the VMTF top-head

• Electrical check-out is in progress

• Cool down start: this weekend or early next week

LARP CM13 – BNL – Nov. 4-6, 2009

Test GOALS

• Achieve target gradient 200 T/m– Compare with TQ02-series

• Understand training– Compare with TQ02-series

• Understand if limitation is due to mechanics and/or coils– Understand if changing one coil could improve “significantly”

performance for next test

• Memory after thermal cycle• Understand behavior at 1.9K

• Inner Layer “bubbles” could cause coil-heater shorts!

• Could reduce the number of usable protection heaters

LARP CM13 – BNL – Nov. 4-6, 2009 G. Ambrosio - Long Quadrupole

Present LQ FY10 plan

Notes:– Coils #14 & #15 start after LQS01 feedback

– Coil #13 delayed because of HQ coils priority

• Plan for success with budget = $1.4 M– Need contingency money in case of “problems”

LARP CM13 – BNL – Nov. 4-6, 2009 G. Ambrosio - Long Quadrupole

LQS01 Test Scenarios

1. Successful (G >= 200 T/m)

2. Limited (G < 200 T/m) by one or two coils

3. There is a flaw in all LQ coils design and/or fabrication technology

4. All coils are damaged during cooldown or testmechanics or quench protection failure, excessive pre-load, …

G. Ambrosio – Long Quadrupole 17

LQS02 (4 new coils) or LQS01b (1 or 2 new coils)

LQS01b (1 or 2 new coils), may need 3rd test

Need analysis to understand cause of limitationMay need 4 new coils (2 out of contingency)Need LQS02 and 3rd test

LARP CM13 – BNL – Nov. 4-6, 2009

G. Ambrosio - Long QuadrupoleLARP CM13 – BNL – Nov. 4-6, 2009

Conclusions

• The test of the first Nb3Sn Long Quadrupole (LQS01) is starting

• We planned the test in order to obtain as much information as possible

• The present LQ FY10 plan is based on success– May need to use contingency in case of limited

performance

Addendum

LQS01 Test Plan - I

Room temperature preparation and cool down (10 days)• Magnetic measurements (z-scan) at VMTF

1st Thermal Cycle (10 days)Test at 4.5 K

• Cold electrical checkout• Magnetic measurements• Quench training• Ramp rate study

Cool down to 3 K• Quench Training• Magnetic measurements• Ramp rate study• Temperature dependence study

Warm up to 4.5 K• Verify quench plateau at 4.5 K

LQS01 Test Plan - II

Warm up to 300 K before 2nd thermal cycle (4 days)• RRR measurements

Cool down (4 days) 2nd Cold Test (10 days)

Test at 4.5 K• Quench training Memory

Cool down to 1.9 K• Verify operation of protection heaters

– To avoid possible damage after first few quenches we will do hi-pot (coil-heaters) and low current trips to verify proper operation of heaters

• Quench Training• Magnetic measurements• Ramp rate study• Temperature dependence study

LQS01 Test Plan - III

Warm up to 4.5 K• Verify quench plateau

• Protection heater study

• Spot heater study

Warm up to room temperature (6 days)• Magnetic measurements (z-scan, use warm-finger of full length)

LARP CM13 – BNL – Nov. 4-6, 2009

1.9K Test

• “Bubbles” are a possible cause for coil-heater shortsElectric arc?

Note: we never had heaters on inner layer

“Original” & Present plans

No 3rd generation

In FY08

In FY07-08,

No ceramic binder

2N + 1R

We had delays, some parts were skipped, but we want to keep the 2009 LQ goal “it can be done, but no without pain!”

Long Nb3Sn Coils R&D

• LARP Long Racetrack (4m coils)1st LR: 90% of ssl w single shell2nd LR: 96% of ssl w segmented shell

Coils: flat, no wedges, no tight constrain on coil cross-section during heat treatment First Long Racetrack

• FNAL Long Mirror (2-4m coil)1st LM (2m coil): ~ssl w PIT strands2nd LM (4m coil): 87%* w RRP

108/127 str.Coils: cos-, with wedges, and tight

constrain on coil cross-section during heat treatment

Front view of mirror magnet

* Using heaters on outer layer