Automatic Sample Changer for Gamma Spectrometry

Added: Aug 07, 2015 10:40 am

STATEMENT OF WORK
For Requisition Number: NB646080-15-04141
TITLE: Automatic Sample Changer for Gamma Spectrometry
LAB REQUESTING SERVICE: Material Measurement Laboratory, Chemical Sciences Division, Elemental Measurement Science Group
I. BACKGROUND INFORMATION
The Chemical Sciences Division, part of NIST's Material Measurement Laboratory, serves as the Nation's reference laboratory for chemical measurements and standards to enhance U.S. industry's productivity and competitiveness, assure equity in trade, and provide quality assurance for chemical measurements used for assessing and improving public health, safety, and the environment. The Chemical Sciences Division is responsible for development and characterization of Standard Reference Materials (SRMs) to enhance chemical measurement comparability within the U.S. and to provide a basis for measurement comparability with other nations. The Elemental Measurement Science Group within the Chemical Sciences Division, relies on the use of High purity germanium (HPGe) gamma-ray detectors in gamma ray spectrometry measurements to carry out neutron activation analysis for the value assignment of NIST SRMs, the characterization of research and industrial materials, and the characterization of samples provided by other U.S. Agencies. This sample changer is intended to expand the gamma spectrometry capabilities by enabling higher throughput of samples as well as continued out-of-hours operation. It will support the available gamma spectrometry capacity for highest quality analytical work on a 24/7 basis.

II. SCOPE OF WORK
The planned sample changer will be employed in neutron activation analysis. It will accommodate sets of irradiated samples to be measured by high resolution gamma spectrometry. It is designed to transport samples from a storage area into a detector position within a lead shield and, after a preset counting time, back to the storage. The samples will be in form of 50 mm X 9 mm petri dishes or standard 20-mL scintillation vials, either handled by the pick-up tool of the sample changer directly or by means of custom made sample holders.
III. SPECIFICATIONS

The Contractor shall provide an automatic sample changer system for the automatic transportation of samples with a pick-up tool from a storage area.

System Requirements:
1. Dimensions shall be (max. width, length, height) = (4 ft, 8 ft, 10 ft)
2. The system shall be housed in one frame that is divided into two functional parts, the sample storage area and the detector area.
3. Horizontal transport range between the functional parts shall be within the length of the system.
4. A base plane height for bottom detector shielding support shall be defined to allow insertion of a dewar for a standard dipstick germanium detector (typically 80 cm clearance).
5. Storage area shall have a minimum capacity of 20 samples, either in a sample tray or a disk. The storage area shall be designed to be shielded with a 30 cm height, 5 cm thick lead shield made of standard lead bricks, 5 cm x 10 cm x 20 cm. Standard lead bricks to be provided by NIST.
6. The sample transfer shall be accomplished with a pick-up tool suitable for the physical form of the samples.
7. The pick-up tool shall be self-centering to securely pick up the sample; the tool shall recognize failure (e.g., no sample in position) and generate an appropriate failure status in the control unit. The tool shall feature a positive close and grasp design, so that in the event of an unexpected power loss the sample will not be dropped.
8. The sample changer pick-up tool shall be capable of transporting samples contained in 50 x 9 mm petri dishes or standard 20 mL scintillation vials. The samples may be transported either directly or, if necessary, in Contractor provided sample holders.
9. The pick-up tool shall place the sample / sample holder precisely in the detector position; the X-, Y-, and Z-position of the sample shall be reproduced within ± 1.0 mm in all dimensions. The pick-up and return position on the sample storage tray or disk shall be reproduced with similar precision.
10. Limit switches shall be provided for all travel directions of the pick-up tool to prevent damage to the tool or a sample.
11. The detector shall be located in a lead "4π" shield, 50 cm height with approximately 15 x 15 cm internal dimension. The lead wall thickness shall be 10 cm and the constructed using standard lead bricks stacked in a steel shell and lined with copper/tin (lead bricks and copper/tin to be provided by NIST)
12. The bottom plate of the "4π" detector shielding shall allow insertion of a 100 mm diameter detector endcap and the top plate shall be a movable lid with 10 cm lead layer (NIST may supply this lead).
13. Contractor shall provide a programmable automation system to control the sample changer and locally display the status and other operational parameters. The control unit shall be interfaced to the gamma spectroscopy data acquisition system, a computer system provided by NIST, see 15. The sample changer automation system shall interact with commercial gamma spectroscopy data acquisition systems via TTL-Level (+ or -) signals over BNC connectors.
14. The programmable automation system shall control the change sequence: pick-up of a designated sample, sample transport to the detector position, setting the sample into the detector position, retracting the pick-up tool, closing the lid, waiting for end of count, opening the lid, pick-up of the sample, returning the sample to the storage, selecting the next sample, etc.
15. The NIST data acquisition system uses commercial gamma spectroscopy software such as Gammavision (Ortec) and/or Genie PC (Canberra) for gamma spectrometry data acquisition. The contractor supplied sample changer automation system, shall work with the before mentioned gamma spectrometry data acquisition.
16. An executable program or data template file shall be installed on the data acquisition computer (Windows 7) for definitions of sample pick-up, sample measurement duration, and the data storage file associated with the sample.
17. The position of sample container shall be centered with the center of the detector for the counting period and the following options for the distance of the sample container to the detector endcap. The pick-up tool shall release the sample container at the following positions:
-on the detector endcap.
-5 cm above the detector endcap
-10 cm above the detector endcap
-20 cm above the detector endcap

Installation:
The Contractor shall install the instrument at NIST Gaithersburg, MD. Installation shall include, at a minimum, uncrating/unpacking of all equipment, set-up and hook-up of all equipment, start-up, and demonstration of specifications. Instrument will operate to manufacturer's specifications upon installation. Installation will take place during normal business hours, between 9:00 am and 5:00 pm Eastern Time, Monday through Friday except Federal Holidays, and will be coordinated with the NIST Technical Point of Contact (TPOC). Installation is to occur within 12 weeks of award.

Warranty:
The Contractor shall provide a one year warranty for the system. All hardware and software shall be covered. The warranty shall cover all parts, labor and travel. Only OEM certified parts shall be used in the repair and maintenance of the instrument. The warranty shall commence upon successful completion of delivery, installation, training and demonstration of all required specifications.

During the warranty period, the Contractor shall provide email and/or telephone support during normal business hours, and on-site service, and replacement of any defective equipment or software. The Contractor must respond to NIST personnel requesting service by email or phone not later than twenty-four hours after receiving a request for service or technical support. The Contractor must provide their best effort to be on-site at NIST within ten business days of the initial request for service.

Training:
Include training at NIST for up to 4 NIST personnel covering normal operation, troubleshooting, and routine maintenance. Training will be provided during normal business hours, between 9:00 am and 5:00 pm Eastern Time, Monday through Friday, except Federal Holidays, and will be coordinated with the NIST TPOC to ensure maximum availability of NIST personnel. Training may be completed on-site at NIST immediately after installation and demonstration of specifications.

IV. PERIOD OF PERFORMANCE
The period of performance shall cover delivery 12 weeks after award, installation and training 16 weeks after award, and a one year warranty upon acceptance.

V. PLACE OF PERFORMANCE
Equipment will be delivered to NIST Gaithersburg. Installation of the automatic sample changer shall be accomplished by the Contractor and the Technical Point of Contact at NIST, Gaithersburg, Maryland. Normal duty hours are Monday through Friday, 9:00 am to 5:00 pm Eastern Time with the exception of Federal Holidays.

VI. DELIVERABLES
Description Quantity Due Date
Automatic Sample Changer 1 12 weeks after award
Installation 1 16 weeks after award
Training 1 16 weeks after award

VII. GOVERNMENT ACCEPTANCE
Acceptance/inspection will be determined by the TPOC at NIST following Contractor Installation and Training. Acceptance will be based solely on the System Requirements listed in Part III - SPECIFICATIONS of the SOW. NIST TPOC shall use the demonstration of specifications by the Contractor during Installation and Training to determine acceptance.