TF SBIR2012

File:99462.pdf

1.) Scientific/Technical Approach

Hall probes are available which are rated to 10^15 n/cm^2 at 0.1 MeV. Why aren't these OK for FRIB when the neutron fluence is 10^10 n/cm^2/s. The FBIR division director support letter indicates that NMR probes will be used but no mention of Hall probes. They indicate the current method of inserting a (NMR?)probe, measuring the B-field with beam off, and then tuning the beam will lead to long beam tuning times.

Does the B-field change in the presence of the beam?

Why not put thermal neutron shielding upstream of a Hall probe monitoring a fringe field? 

Temperature probes using the technology are shown to survive the high neutron fluence,
will the technique used to look for B-field induced shifts survive.  
What is the shift for temperature fluctuations compare to that induced by B-fields?

FRIB uses 0.5-2.5 Telsa strength magnetic dipoles to separate rare isotopes. Currently Hall probes are used to set B-field and then remove probe during operation to prevent damage. Gamma, neutron, and proton fluxes are about 2 E10 n/cm^2/s (mostly thermal neutrons).

If its mostly thermal neutrons then why not park the hall probe near the dipole field and shield it with a thermal neutron capture them with a liner?

 Why do you need to monitor the B-field when beam is on?

Optical Frequency Domain Reflectometry will be used to measure B-field to an accuracy of 0.01%. Probes will be able to withstand fast neutron fluxes of 10^18n/cm^2 = 1 year in the FRIB.

a.) To what extent does the proposal build upon or extent current stat-of-the-art

The project proposes adapt Optical Frequency Domain Reflectometry technology licensed from NASA to develop a 0.5 - 2.5 Telsa magnetic fields monitoring device that can withstand radiation environments containing thermal neutron fluxes on the order of 2 E10 n/cm^2/s. Luna is currently using the technology to measure temperature and strain at locations that are about 30 micron in size.

b.) How new or unique is the idea

The company has a history of using the technique

c.) Hos significant is the scientific or technical challenge

d.) Is a breakthrough possible

The propsal seek to develop a device to measure the magnetic field of a dipole (0.5 - 2.5 T)to an accuracy of 0.01% which can survive in a radiation environment with a neutron, gamma, and proton combined flux of 10^10 particle/cm^2/s. There is a statement that thermal neutrons make up most of the flux. There is little information on how much of the remaiing flux is from photons and protons thus it is difficult to determine if the device could be degraded from the radiation damage of the photons or protons.

e.) does applicant have knowledge of the subject

f.) have concepts been presented thoroughly

2.) Ability to carry out the project in a cost effective manner

a.) Qualification of the PI ,staff, and facilities

b.) soundness of Phase I work

On pg 7 of the proposal it was stated that Object 1 for phase 1 will be to determine the sensor requirements need by FRIB. This is a little confusig given the goals shown on pg 13 would imply that the Objective for phase 1 has already been achieved?

c.) does effort justify the cost.

3.) Impact

a.) benefits of proposed work to technology or economy

b.) liklihood work will lead to marketable product

The device may be able to meausure magnetic field strength, can more of them be used to measure the B-filed direction?

c.) liklihood product will attract further funding