# Presentation: 608309

## High Power Target and Target/Horn Integration R&DCurrent & Future Plans

**N. Simos**
**BNL**

## Targets for 2 - 4 MW Proton Sources?  

**Aim pushes the envelope beyond our current understanding of material behavior under conditions of extreme severity**
**There is no available accelerator even near the power we are seeking (< 1/10 power currently available) for testing under **_**remotely **_**similar conditions**
**However, we can be smart and conduct dedicated experiments (matched with state-of-the-art simulations) that will enhance our understanding in areas that are outside the limits of what has been achieved to-date**
**Experiments for high intensity proton beam/target interaction (thermal shock) as well as material damage from prolonged radiation exposure will serve a wide range of initiatives (neutrino beams, neutrino factory, etc.)**
**BNL targetry program has been formulated and pursued to address issues associated with a wide range of materials (low to high Z)**
**	****Solid Targets    ******** ****irradiation damage assessment, beam-induced shock**
**	****Liquid Targets ******** ****Hg jet interacting with intense proton pulses (and magnetic fields)**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## Is 4-MW Source Practical?  

**Several “smart” materials or new composites may be able to meet desired requirements:**
**new graphite grades**
**customized carbon-carbon composites **
**Super-alloys (gum metal, albemet, super-invar, etc.)**
**While calculations based on non-irradiated material properties **
**may show that it is possible to achieve 2 or even 4 MW, irradiation **
**effects may completely change the outlook of a material candidate**
**ONLY way is to test the material to conditions similar to those expected **
**during its life time as target**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## Overview of BNL Target Studies

- Beam on targets (E951)
- Hg Jet
- Solid Targets & Beam Windows (thermal shock)
- Material Irradiation and Damage Assessment (ongoing at the BNL hot cell facilities)
- New activities (in planning)
- Hg jet target intercepting intense proton pulses in a 15 Tesla magnetic field (CERN experiment)
- Irradiation studies at BNL BLIP
- irradiation studies/beam on targets (p-bar at FNAL)
- Laser-based target shock studies
- Simulations and benchmarking

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## BNL E951 Hg Jet Experiment 

**BNL E951 Hg Jet Experiment **

_**Hg Jet target issues to be addressed in R&D:**_
**Behavior of the Hg jet after entering 15-20 T magnetic field**
**Survival of jet from ****	****(a) single proton pulse; **
**	****	****(b) pulse train separated by ns**
**mode of jet break-up and velocity of projectiles **
**ways to achieve jet speeds of 20 m/s**
**effects of backward traveling pressure waves on the jet nozzle**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## BNL E951 Hg Jet Experiment - Simulations Snapshots of Hg Jet destruction following rapid heating from proton beam

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## 24 GeV AGS Protons on Graphite & CC Composite Targets

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## WHY Carbon-Carbon and not graphite?

**WHY Carbon-Carbon and not graphite?**

_**IRRADIATION EFFECTS ON GRAPHITE**_
**Irradiation has a profound effect on thermal conductivity/diffusivity**
**CC composite at least allows for fiber customization and thus significant **
**improvement of conductivity. **
**NOTE**** that assessment of irradiation effects on conductivity of CC composite **
**yet to be completed **
** **

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## 24 GeV AGS Protons on Targets/Beam Windows

**24 GeV AGS Protons on Targets/Beam Windows**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## Beam Target/Window Experiment (E951)  Experimental Strain Data vs. Simulation

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## BNL IRRADIATION STUDIES

_**PHASE I**_**:**
-  **Super Invar **
** ****Inconel-718**

**Carbon-Carbon Composite in Target **
**Assembly**

**Nickel-plated aluminum in target assembly (goal is to find out how irradiation affects bonding)**

**  ****3D Carbon-Carbon Composite **
**   ****Toyota “Gum Metal”**
**   ****Graphite (IG-43) **
**   ****AlBeMet **
**   ****Beryllium **
**   ****Ti Alloy (6Al-4V) **
**   ****Vascomax **
**   ****Nickel-Plated Aluminum **

**Complex assembly of target materials**

**BEAM PARAMETERS**
- 200/117 MeV protons; ~ 70 μA
- Spot size  FWHM ~ 14 mm

**BEAM**

_**PHASE II**_**:**

_**PHASE II-a**_**:**
**2D Carbon-Carbon Composite**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## Slide 12

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## Slide 13

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## BNL BLIP Irradiation Temperature Assessment viaThermal Sensitive Paint (TSP)

**BNL BLIP Irradiation Temperature Assessment viaThermal Sensitive Paint (TSP)**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## Post-Irradiation Testing at the BNL Hot Cell Facility

**Post-Irradiation Testing at the BNL Hot Cell Facility**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## WHY DO WE WANT TO DO THESE TESTS?

**WHY DO WE WANT TO DO THESE TESTS?**

- Non-irradiated HORN material

**Ni-plated material AFTER irradiation**

**Is nickel-plating the way to prolong life of HORN?**
**Jury is still out BUT preliminary assessment not favorable**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## CC composite “annealing” behavior

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## Super Invar: Serious candidate?

**Super Invar: Serious candidate?**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## GUM Metal

_**GUM Metal**_
**90% cold-worked may be of interest (if it holds these properties after irradiation)**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## Vascomax

**Vascomax**

**Ti alloy (6Al-4V)**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## AlBeMet

**AlBeMet**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## 2D carbon-carbon Irradiation at BNL BLIP Facility(received ~5x the dose of the 3-D CC)

- 2D carbon-carbon Irradiation at BNL BLIP Facility(received ~5x the dose of the 3-D CC)

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## Preliminary 2D carbon-carbon post-irradiation – Surprise Surprise !

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

##  Neutrino Beam Target/Horn Integrated System Concept

- insulator

- Horn

- Target

- Forced helium

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

##  Proposed Activities

_**Irradiation damage and shock studies of target & horn materials  **_
- Expose materials considered promising from the current BNL experimental studies to irradiation damage levels anticipated in the real experiment
- 	3-D carbon-carbon; super-Invar, “gum metal”, Vascomax, Albemet, etc.
- Assess the degradation of physical and mechanical properties of interest
- 	conductivity; CTE; resistivity; strength; fatigue; fracture toughness, etc.
- Assess target shock response under increasing levels of irradiation exposure
_**Target/Horn Integration R&D**_
- Forced cooling using pressurized gas (helium) – avoid corrosive nature of water – under highly demanding conditions
- Optimization of insulating elements (decoupling of horn and target) including irradiation damage assessment
- Optimization of horn geometry for best neutrino flux and integration with optimal target configuration – Search for alternative horn materials (i.e., Albemet)

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## Target Shock + Irradiation Exposure Studies 

**Use of 120 GeV Beam of Pbar Facility (FNAL)**

_**What we hope to get out of it ?**_
**Shock induced failure**
**- Information regarding damage at different doses and at different different ratios of protons to neutrons**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## Off-beam Target Shock Studies 

_**Off-beam Target Shock Studies **_
**Use of High-Power Laser (BNL)**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

##  Proposed Activities – Liquid Targets

**MERIT Experiment**** (Hg jet intercepting intense proton pulses in magnetic field)**
-  **experimentally confirm both the jet dispersal characteristics and ability to replenish target between successive pulses**
** ****explore the feasibility of 50 Hz operation**
**Benchmark magneto-hydrodynamic simulations that will, in turn enable the feasibility assessment of multi-MW liquid target and/or its limitations **

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## MERIT Experiment Layout

**MERIT Experiment Layout**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## MERIT Experiment Simulations

- Hg Jet

**MERIT Experiment Simulations**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## Preliminary Hg dispersal analysis induced by beam

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## SUMMARY

**High power targets****, regardless of the physics they will support, are inherently coupled with material R&D (shock and irradiation damage)**
**Information to-date is available from low power accelerators and mostly from reactor (neutron irradiation) experience. ****Extrapolation is not allowed!**
**Advancements in material technology**** (alloys, smart materials, composites) provide hope BUT must be accompanied by ****R&D for irradiation damage**
**Liquid targets (Hg jets)**** may be the answer to neutrino factory initiative BUT the necessary experiments of the integrated system must be performed. Too many unknowns to be left unexplored**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005

## SUMMARY (cont.)

**Solid target shock experiments**** with pulse intensities anticipated in the multi-MW proton driver are necessary **
**The feasibility of an integrated target/horn system**** for the conditions demanded by the multi-MW neutrino beam needs to be studied with dedicated experiments of heat removal by forced helium (to get away from cooling water and its consequences), pulsing, and fatigue **
**Simulations of target/beam interaction**** (solids and liquid jets) that are benchmarked on the various experiments are a MUST. Predicting the mechanics of shock and of magneto-hydrodynamics (while benchmarking simulations to experiments) will allow us to push the envelope to the conditions of the multi-MW drivers**

- Neutrino R&D Proposal - Target Studies

- Nov 14, 2005