Specifications_1.pdf

PCMSC Gamma Counting System

Background The U.S. Geological Survey Pacific Coastal and Marine Science Center (PCMSC) in Santa Cruz, CA relies on in-house gamma-counting to characterize hazards, risk, and resource resilience, topics that are national and Department of the Interior science priorities. The existing instrumentation at PCMSC is decades old, obsolete, subject to failure, cannot be networked, and must therefore be replaced to ensure operational continuity. Gamma system operations and quality assurance must be suitable for entry-level users. Typical samples are aquatic sediments with low radionuclide activities, varying densities, and varying volumes (geometries) from 1 milliliter (ml) to 10 ml.

Scope of Work PCMSC will acquire a complete new, non-portable gamma-counting system that includes all necessary equipment, instrumentation, lead shield, software package(s) that simplify operations and are suitable for a range of sample types/ densities/volumes, and a cryogenic liquid nitrogen recycler (see component list below). The new system must fit in with the existing lab space and be compatible with in-house sample vials (dimensions given below). The vendor will complete on-site installation, system configuration, software set-up, quality assurance testing, and user training.

Gamma System Components

1. High-purity low-background germanium (HPGe) Well Detector for gamma ray counting with oxygen-free high-purity copper endcap, high-purity aluminum well tube, and remote preamplifier and high voltage (HV) filter.

a. Well tube diameter: 15.5 to 16 millimeters (mm), fits in-house 10-ml volume, 15-mm outer-diameter sample vials

b. Well tube depth: 40 mm (at least)

c. Volume: 120 cubic centimeters (cc) (at least)

d. Endcap diameter: 70 mm or approximately.

e. Resolution at 122 keV = 1.4 keV at full width half maximum height (FWHM)

f. Resolution at 1.33 MeV = 2.3 keV FWHM or approximately.

g. It shall be possible for the user to perform detector efficiency calibrations locally without factory assistance. Accordingly, the detector shall not require any factory efficiency or response characterization to enable use of the HPGe Well detector with the application software for nuclide quantification.

2. Low-background J-type Cryostat with remote preamplifier.

3. Cryogenic Liquid Nitrogen Recycler with 25-liter capacity compatible with detector and J-type cryostat with remote preamplifier. Quote shall include a 2-year warranty.

4. Low background lead shield with 4-inch-thick walls and a graded tin and copper interior liner to eliminate gamma ray interference with sample measurements inside the counting chamber.

The shielding shall be designed to accept a J-style cryostat on the footprint of a standard 30-liter dewar. Quote shall include a stand for the shield and dewar.

5. Standalone, digital, multi-channel analyzer (MCA) signal processing gamma spectrometer with digital amplifier, single internal high voltage (HV) power supply. Communication between the digital MCA and the Windows PC shall be possible by Ethernet or USB. Quote shall include cost of any needed 10-foot cable(s) if not included with the HPGe Well detector.

a. MCA Emulation software application capable of operating all computer-controllable MCA hardware functions compatible with Multichannel analyzers that operate and communicate via 64 bit protocols, supporting data acquisition, nuclide library use and editing, display, and quantitative analysis.

6. HPGe Detector Efficiency Transfer software application. The application shall allow the user to generate sample geometric efficiencies from the known efficiency of a reference configuration. A solid angle model will be used to derive the efficiency from a single reference for different containers, sample materials, and sample positions. The software shall additionally create a Geometry correction file for use with the quantitative analysis software application so that the final analysis results retain traceability to the Reference calibration while applying the necessary efficiency corrections to the derived geometry configuration.

Cascade Summing Corrections are calculated with correction factors applied to the nuclide branching ratios to account for coincidence summing of photon emissions from a single atom, a factor that is significant for well configurations where samples are close to the detector.

7. A user-friendly gamma analysis productivity software application (networked) to automate and/or streamline and/or customize gamma spectroscopy sample management, data entry, calibration, quality assurance/control, reporting, data management and export, and remote access/data acquisition. The application software shall:

a. Maintain a comprehensive event log and provide standard and simplified report generation tools that are integrated into the software as an interactive report generation tool. No third-party applications like Crystal Reports will be required to edit report content produced by the application software.

b. Provide an Excel Addin, so advanced calculations shall be possible using VBA or Excel worksheet fields to provide extensive calculations or automation outside of the standard automation provided by the application software.

c. Provide a simplified means of local database management that includes the ability to:

Purge, Archive, and Backup data. This data management shall not require any third-party database management tools such as: SQL Server, ORACLE, MS Access, or SQL Lite. Quote shall include 4 days of on-site installation, configuration, user training, and travel expenses.

Warranties

8. Extended Warranties (5 additional years) for labor, materials, and return shipping for:

a. HPGe well detector

b. J-type cryostat

c. Liquid Nitrogen recycler

d. Multi-channel analyzer (MCA)

Technical Support (on-site)

9. Technical support, service, and/or training – A single 2-day on-site follow on, post-installation support visit for training and/or technical support including travel costs in Year 1, 2 or 3 after purchase.

Special Requirements Software Requirements

• Software must be compatible with the Windows 11 operating system.

• Software packages must be approved by the U.S. Department of the Interior to be used on networked federal information systems (i.e. a networked USGS computer).

Space requirement (footprint)

• The existing space in the PCMSC Gamma Lab is 30” deep (out from wall) x 60” wide x 54” high.

Well size requirement

• The well detector must fit existing, current-use sample vials measuring 15-mm outer-diameter and 10-ml volume.

Shipping USGS will pay shipping costs with a FedEx account.

Period of Performance Period of Performance will be 12 months from the date of the award (excluding post-installation warranties and technical support) and can be extended for unforeseeable or unavoidable delays for the Vendor or for USGS PCMSC.