ORTEC ULTRA-AS

Low-background silicon detectors for alpha spectroscopy

ORTEC ULTRA-AS comprises 8 models (low-background silicon detectors for alpha spectroscopy). The models differ in active area, depletion depth and warranted resolution, among other things – compare them in the model table.

Detector type: Ion-implanted silicon, partially depleted1
Active depth: ≈100 µm2

Download product sheet (PDF)All values with references – for tender documents

Specifications checked against the manufacturer’s documents on 2026-10-16

Manufacturer’s product page (opens in a new tab)

Overview

Nuclear power & nuclear technology Research & laboratories Environmental monitoring & radiation protection

Specifications

The number after each value refers to the source listed below. Values are as published by the manufacturer; the exact configuration is always confirmed in our quotation.

Detector type	Ion-implanted silicon, partially depleted1
Active depth	≈100 µm2
Resolution measurement conditions	²⁴¹Am 5.486 MeV alphas; standard ORTEC electronics; 1 µs shaping time constants3
Resolution measurement and warranty temperature	21 ±1 °C1
Bias polarity	Positive3
Resolution reference geometry	Thin-window point source; distance at least 2 times the detector diameter4

The data comes from the manufacturer’s published documents. Manufacturers may change specifications; the current configuration and performance are confirmed in the quotation.

Models

8 models in the series. Filter or scroll the table to compare.

8 / 8

Model	Minimum active area2	Guaranteed maximum alpha resolution2	Ordering mounts2	Alpha Suite compatibility2	Installation and spare packages
U-019-300-AS	≥300 mm²	≤19 keV FWHM	B, C, T (closed back)	ULTRA-AS in B mount is guaranteed compatible; C/T mounts require an approved special	B, C or T mount; ENS-U300: B mount, installed and system tested with an Alpha Suite spectrometer; ENS8U300: pack of eight spare detectors (not installed or system tested), only with an ALPHA-ENSEMBLE-8 system2
U-020-450-AS	≥450 mm²	≤20 keV FWHM	B, C, T (closed back)	ULTRA-AS in B mount is guaranteed compatible; C/T mounts require an approved special	B, C or T mount; ENS-U450: B mount, installed and system tested with an Alpha Suite spectrometer; ENS8U450: pack of eight spare detectors (not installed or system tested), only with an ALPHA-ENSEMBLE-8 system2
U-020-490-AS	≥490 mm²	≤20 keV FWHM	B, C, T (closed back)	ULTRA-AS in B mount is guaranteed compatible; C/T mounts require an approved special	B, C or T mount; ENS-U490: B mount, installed and system tested with an Alpha Suite spectrometer; ENS8U490: pack of eight spare detectors (not installed or system tested), only with an ALPHA-ENSEMBLE-8 system2
U-024-600-AS	≥600 mm²	≤24 keV FWHM	B, C, T (closed back)	ULTRA-AS in B mount is guaranteed compatible; C/T mounts require an approved special	B, C or T mount; ENS-U600: B mount, installed and system tested with an Alpha Suite spectrometer; ENS8U600: pack of eight spare detectors (not installed or system tested), only with an ALPHA-ENSEMBLE-8 system2
U-029-900-AS	≥900 mm²	≤29 keV FWHM	B, C	ULTRA-AS in B mount is guaranteed compatible; C mount requires an approved special	B or C mount; ENS-U900: B mount, installed and system tested with an Alpha Suite spectrometer; ENS8U900: pack of eight spare detectors (not installed or system tested), only with an ALPHA-ENSEMBLE-8 system2
U-037-1200-AS	≥1200 mm²	≤37 keV FWHM	B, C	ULTRA-AS in B mount is guaranteed compatible; C mount requires an approved special	B or C mount; ENS-U1200: B mount, installed and system tested with an Alpha Suite spectrometer; ENS8U1200: pack of eight spare detectors (not installed or system tested), only with an ALPHA-ENSEMBLE-8 system2
U-053-2000-AS	≥2000 mm²	≤53 keV FWHM	B, C	ULTRA-AS in B mount is guaranteed compatible; C mount requires an approved special	B or C mount; ENS-U2000: B mount, installed and system tested with an Alpha Suite spectrometer3
U-064-3000-AS	≥3000 mm²	≤64 keV FWHM	B, C	ULTRA-AS in B mount is guaranteed compatible; C mount requires an approved special	B or C mount; ENS-U3000: B mount, installed and system tested with an Alpha Suite spectrometer3

Documents

PDFULTRA and ULTRA AS Ion-Implanted-Silicon Charged-Particle DetectorsDatasheet · ORTEC

Sources

The number after each value refers to the source listed below. Values are as published by the manufacturer; the exact configuration is always confirmed in our quotation.

1
Si Charged Particle Radiation Detectors for Alpha Spectroscopy
Publisher: ORTEC (AMETEK)Product page ULTRA / ULTRA AS comparison table ('Diode Structure') and footnote †; footnote * below the introduction text Checked 2026-10-16
2
ORTEC Product Guide
Publisher: ORTEC (AMETEK)Product catalogue PDF p. 4 (printed p. 1), 'ULTRA-AS Ion-Implanted Detectors' note; PDF p. 4 (printed p. 1), table 'ULTRA-AS Ion-Implanted Detectors', Active Area column; PDF p. 11: 'The next group of dig; PDF p. 4 (printed p. 1), table 'ULTRA-AS Ion-Implanted Detectors'; PDF p. 11 (printed p. 8), table 'Standard Mounting Information' … Checked 2026-10-16
3
ULTRA and ULTRA AS Ion-Implanted-Silicon Charged-Particle Detectors
Publisher: ORTEC (AMETEK)Brochure p. 2–3, footnote * under the ULTRA / ULTRA-AS ordering tables; p. 1, footnote **; p. 3, table 'ULTRA-AS to be installed and system tested with an Alpha Suite Spectrometer. Supplied in B Mount' Checked 2026-10-16
4
Introduction to Charged-Particle Detectors
Publisher: ORTEC (AMETEK)Application note PDF p. 3, 'Energy Resolution and Noise' Checked 2026-10-16