hypervelocity impact lab at jhu...kirana and shimadzu hpv-x2 • flash x-ray imaging –two channel...

Planned Diagnostics

• Ultra High Speed Imaging - Up to 10 Mfps video with

Kirana and Shimadzu HPV-X2

• Flash X-Ray Imaging – Two channel 300 kV system,

orthogonal soft x-ray tubes

• UV-VIS and Infrared Spectroscopy

• Photon Doppler Velocimetry (PDV) for surface

velocimetry

• Hyperspectral Snapshot Camera (via CASSI) and 3D

Particle Tracking system in development by JHU

collaborators

Hypervelocity Impact Lab at JHUG. Simpson1*, M. Shaeffer1, D. Mallick1,2, K.T. Ramesh1

1. Hopkins Extreme Materials Institute, The Johns Hopkins University, Baltimore, Maryland 21218

2. U.S. Army Research Laboratory, Aberdeen, Maryland 21005

OverviewHEMI researchers are interested in material behavior under a broad range of dynamic conditions. To improve our fundamental understanding of these problems, HEMI has built a hypervelocity impact facility at JHU including a two-

stage light gas gun and enclosed projectile range. The system is designed to accommodate a range of target/ impactor configurations and diagnostics, with flexibility to add capabilities in the future. The facility is expected to be

operational by the end of the calendar year.

Problems of Interest• Fragmentation of Impactors/Targets

• Protective Materials and Structures

• Planetary Impact of Geological Materials

• Impact of Space Debris and Micro-meteoroids

• Multiphase mechanics of high energy impacts

Gun System DescriptionThe hypervelocity impact lab hosts a two stage light

gas gun with a launch tube diameter of 7.62 mm. The

system utilizes a compressed gas breech (as opposed

to smokeless powder) in order to minimize handling

risk, decrease fouling and increase shot-to-shot

consistency. The facility is equipped for hydrogen use,

allowing a maximum launch velocity of approximately

7 km/s. Both smoothbore and rifled barrels will be

available for use.

Gun and Target Tank

Acknowledgements

HEMI thanks Dr. Kevin McNesby of ARL, Dave Strange of PAI,

Don Grosch of SwRI, and the members of the Hypervelocity

Impact Symposium and the Aeroballistics Range Association for

their help and feedback.

Source: PAI

Initial Research

After installation, the hypervelocity facility will be used

initially for DoD funded work involving the fragmentation

of impactors. Experiments to capture and observe the

failure of an impacting body as well as the resulting

fragment cloud will be performed with the goal of

characterizing the mechanisms controlling the dynamic

fragmentation of projectiles and colliding bodies.

Velocity Performance

All combinations of launch mass and velocity below

this curve are accessible. Accelerated mass includes

projectile and sabot.

Accelerated reservoir increases

pressure, rupture disk failure

launches projectile

Drift tube section with multiple ports for imaging

projectile free flight and measuring projectile velocity

Target chamber 3 ft diameter by 3 ft long to

accommodate various targets. Internal rails

provided for mounting

Orthogonal configuration for

flash X-ray heads

Blast tank for gas expansion and

sabot separation

7.62 mm diameter launch tube, can be

smooth or rifled to aid in sabot separation

30 mm diameter pump tube –

H2 or He fill gas

Breech – 10,000 PSI He or N2

to drive pump tube piston

5 rectangular viewports along shot

line, 3 circular viewports looking at

target plane, dedicated pass

through for in-chamber sensors

* Email: gsimps10@jhu.edu

𝑉𝑝𝑟𝑜𝑗

Flash X-Ray

Ultra High

Speed Imaging

Flash X-Ray