Strawman TXR Deployment Test PlanFor a Generic Host Chamber

Joe RiceNational Institute of Standards and Technology

Gaithersburg, MD

•This presentation is intended as a generic example of how a TXR deployment might work, and is intended for those who need a practical example.•We present this as a generic case because certain interface and test plan details for specific chambers may be considered confidential.•Because of the many assumptions that must be made for the generic case, the test plan details would be expected to vary greatly for a specific chamber.•Despite this, it is the intent to keep total chamber time involved with the deployment to below 2 weeks.

Introduction

Assumptions about Generic Host Chamber

• TXR has a direct view of black body source (no mirrors).• Environment is near room temperature, vacuum.• Blackbody source under test is variable temperature, within the range 200

K to 400 K, with ability to come to equilibrium within an hour for successively increasing setpoints.

• Cooling black body and environment from highest T to lowest T can be accomplished overnight.

• Time from chamber closure to initial TXR LN2 fill is <24 hrs.• Time from end of testing to chamber opening is <24 hrs.• Normal work hours are within 8am - 6pm , Monday through Friday.

(Although we assume this here, we can certainly accommodate a 24 hr work schedule where that is the norm.)

Major Objectives of Test

•Measure response of TXR Channels 1 and 2 to the black body in-situ radiance at a statistically significant number (9 or more) of well-equilibrated temperatures that span the range used.•Repeat the measurements at least once under identical conditions, presumably on a separate day(s).

Two-Week Chamber Test Plan

•Week 0: TXR and its accessories (about 1200 lbs gross weight) are delivered to host facility and are located in an off-line space.•Week 1, Monday (optionally could be moved up to Week 0, Friday):

–Unpack & begin repumping TXR cryostat vacuum with turbo pump.–Functional checkout of TXR at room-temperature.

•Week 1, Tuesday: –Valve-off TXR cryostat vacuum space.–Load TXR cryostat into chamber and position TXR racks.–Make electrical connections to cryostat and racks & power up.–Align TXR with respect to source under test using TXR laser.–Make cryogenic connections to TXR cryostat.–Close chamber and begin chamber pumping.

•Week 1, Wednesday:–Initial LN2 fill of TXR cryostat (<30 minutes).–Preliminary TXR measurements at lowest black body setpoint.

Two-Week Test Plan (continued)

•Week 1, Thursday:–First day of genuine data acquisition.–Series of source T’s from lowest to highest, reaching equilibrium at each of 9 pre-determined setpoints.–TXR acquires 10 minutes of data into reduced data files at each equilibrated T plateau.–Source under test set to cool back to lowest T overnight.–TXR performs automated checksource measurements overnight.

•Week 1, Friday:–Repeat of Thursday: second day of genuine data acquisition.–Quick assessment of data repeatability.

•Week 2, Monday-Thursday:–Contingency for problems.–Optionally: more repeats of genuine data acquisition.–No LN2 refill on evening of last day. Purge cryolines to warm up overnight. Backfill chamber to assist warming.

•Week 2, Friday:–Ensure that cryoline temperatures are above dew point.–Open chamber, remove TXR cryostat.–Pack TXR and its accessories.

•Week 3:–TXR is shipped back to NIST.