X-123SDD Detection System

The X-123SDD is a complete X-ray detection solution with a silicon drift detector in a compact package that fits in your hand.

Without the use of liquid nitrogen

Fig. 1 Spectrometer X-123SDD.

X-123SDD includes

Silicon Drift Detector (SDD) and Preamplifier
Digital Pulse Processor and Analyzer
Power supply and software compatible with your PC

Advantages

Compactness of the system
Ease of use
Small size (7 x 10 x 2.5 cm)
Low power consumption (2.5W)
Light weight (180g)
USB, RS232 and Ethernet connectors

Application

X-ray fluorescence analysis (XRF)
RoHS/WEE compliance for instrumentation
Control of technological processes
Art and Archaeology

Detector

Silicon Drift Detector (SDD) for X-ray Detection
2-stage thermoelectric cooling
Area: 25 mm2
Thickness: 500 microns
Multilayer collimator

General characteristics

Resolution: 125-140 keV, FWHM at 5.9 keV
Optimal energy range: from 1 keV to 40 keV
Maximum count rate: up to 5.6 x 105 events per second

The X-123SDD is the result of 15 years of development of X-ray detectors by Amptek. The company's philosophy has always been to produce compact, low power consumption, high performance detectors that are easy to operate. The X-123SDD is an example of this philosophy and is a combination of the XR-100SDD silicon drift X-ray detector and its charge sensitive preamplifier; the DP5 digital pulse processor, MCA, software and PC5 power supply in a single housing. And all this requires only +5 V DC and connection to a computer via USB, RS232 or Ethernet.

sdd_12

Fig.2 Spectrum of 55Fe obtained using a silicon drift detector (SDD).

Description

The X-123SDD combines Amptek's high-quality X-ray spectrometry components into a single package: (1) an XR-100SDD X-ray detector with preamplifier, (2) a DP5 digital pulse processor with MCA, and (3) a PC5 power supply. The result is a complete system that fits in your hand without sacrificing performance. The X-123SDD requires only +5VAC and a standard PC connection to operate. With the X-123, anyone can quickly acquire high-quality X-ray spectra.

The X-123SDD uses a silicon drift detector (SDD) similar to a Si-PIN photodiode, but with a unique electrode structure that provides better resolution and counting speed. The SDD is mounted on a thermoelectric cooler with an input field-effect transistor and is connected to a charge-sensitive preamplifier. Thermoelectric cooling reduces the level of electrical noise in the detector and preamplifier, but at the same time the cooling remains open and understandable to the user: it works like a conventional air conditioning system.

The DP5 Pulse Processor is a second generation digital pulse processor (DPP) that replaces both the signal amplifier and the multichannel analyzer (MCA) found in similar systems. The use of digital technology provides improvements in the following key parameters: (1) better performance, such as better resolution and higher count rate; (2) excellent flexibility in configuring settings selected via software; (3) improved stability and reproducibility of results. The DPP digitizes the output signal from the preamplifier using real-time digital signal processing, detects the peak amplitude and collects these values in memory histograms, generating an energy spectrum. The spectrum is then transferred to the user's PC. The PC5 provides power to the detector, low voltage to the preamplifiers and high bias voltage to the detector, and powers the thermoelectric cooling, which provides a closed-loop control with a maximum temperature difference of 85 °C. All this is controlled by the provided software. X-123SDD is powered by +5V with a current of about 300 mA.

The entire system is housed in an aluminum housing measuring 7 x 10 x 2.5 cm 3 . The detector is mounted on an extension cable ranging from 0 to 22.86 cm in length (vacuum flanges are available). In the standard configuration, only 2 connections are required: power supply (+5V) and a PC connection (USB, RS232 or Ethernet). Several additional inputs and outputs are also available if the X123 is integrated with other equipment. This includes a multi-channel analyzer chain and selective signal memory, time control and a single-channel analyzer. The X-123SDD comes complete with data acquisition and control software. It also includes a DLL application programming interface (API) for integrating the unit with custom software. Software for X-ray spectrum analysis, vacuum hardware, several collimator and mounting options, and X-ray tubes can be optionally added to create a complete compact XRF system.

x123sdd_1

Fig.3 Block diagram of X-123SDD and connection diagram.

Characteristics of X-123SDD

General

Energy resolution

125 - 140 eV (full width at half maximum) at 5.9 keV. Dependent on peak time and temperature.

Electrical noise level

73 eV (width at half maximum)

Signal to Noise Ratio

20,000:1 (counting ratio from 5.9 keV to 1 keV)

Energy range

Efficiency >25% for X-rays with energies from 1 to 25 keV. Can operate outside this range, but with lower efficiency.

Maximum counting speed

Depends on peak time. Recommended parameters are presented in the table below:

Peak time DP5 (µs)	9.6	4.8	2.4	0.8
Formation time (µs)	4.4	2.2	1.0	0.4
Recommended maximum speed	4.9 x 10 ⁴	1.0 x 10 ⁵	1.9 x 10 ⁵	5.6 x 10 ⁵
Typical resolution (eV FWHM at 5.9 keV)	130	135	140	155

Detector and preamplifier

Detector type

Silicon Drift Detector (SDD)

Detector area

25 mm2 (collimator area 17 mm2)

Detector thickness

500 microns

Thickness Be of the window

0.5 mil (12.5 µm)

Collimator

Multilayered

Thermoelectric cooling

2-stage (ΔTmax=85°)

Preamplifier type

Charge sensitive, manufactured by Amptek.

Preamplifier Conversion Ratio

1 mV/keV (typical)

Digital Pulse Processor (DPP)

Gain

Combination of coarse and fine gain provides continuous gain from 0.84 to 127.5

Rough amplification

Software selectable from 1.12 to 102.0 in 16 steps:

1.12, 2.49, 3.78, 5.26, 6.56, 8.39, 10.10, 11.31,

14.56, 17.77, 22.42, 30.83, 38.18, 47.47, 66.26, 102.0

Subtle enhancement

Software selectable from 0.75 to 1.25, with 10-bit resolution.

Full scale

1000 mV input pulse at X1 gain

Stability

<20 ppm/°C (typical)

Pulse shape

Trapezoidal (A semi-Gaussian amplifier with shaping time t has a peak time of 2.2t and is comparable to a trapezoidal shape of the same peak time)

ADC clock frequency

From 20 to 80 MHz

Peak time

30 different software selectable values from 0.2 to 102 µs, corresponding to semi-Gaussian shaping times from 0.1 to 45 µs.

Plateau

16 software selectable values for each peak time (peak time dependent), >0.05 µs.

Recovery

Asymmetric, 16 software-selectable convolution rates.

Two-pulse resolution time

120 nano seconds

Dead time

1.05 peak time. No conversion time.

Maximum counting speed

4x10 ⁶ s-1

Dead Time Adjustment

Manual adjustment. Accuracy up to 1%.

Pulse selection options

Overlap rejection, sorting by rise time, pass-through

Multi-Channel Analyzer (MCA)

Number of channels

Software selectable: 8,000; 4,000; 2,000; 1,000; 500; or 250 channels

Bytes per channel

3 Bytes (24 bits) - 16.7x 106 signals

Opening hours

From 10 ms to 466 days

Data transfer time

1,000 channels in 12 ms (USB) or 280 ms (RS-232)

Conversion time

Missing

Preset

Time, total number of invoices, number of invoices per ROI, number of invoices transmitted via 1 channel

MCS Time Base

From 10 ms/channel to 300 s/channel

External MCA controls

Input: Pulse is passed only when the pass is allowed by the external logic system. Software controlled.

Auxiliary I/O channels

Single Channel Analyzer (SCA)

8 SCA

Digital output

Two independent outputs with 8 programmable settings: INCOMING_COUNT, PILEUP, MCS_TIMEBASE, etc.

Digital input

Two independent inputs, software selectable from

MCA_GATE, EXTERNAL_COUNTER

I/O

Two common I/O lines for user application

Digital oscilloscope

The oscilloscope data is displayed on the computer. The software selects whether to show the output signal shape, the input signal to the ADC, etc. They are used for debugging equipment.

Connectors

USB

USB 2.0 (12 Mbps)

Serial

Standard RS232

Ethernet

10base-T

Nutrition

Nominal input

+5 VDC at 500 mA (2.5 W) (typical). Current is highly dependent on the detector's ΔT. Range is 300 to 800 mA at 5 VDC. AC adapter included.

Input voltage range

From 4 V to 5.5 V (at currents of 0.4 - 0.7 A)

The beginning of the transition process

2 A for <100 µs

High voltage

Internal multiplier, software controlled, from -95 to -1500V

Cooling power supply

Feedback controller ΔTmax = 85 °C

Overall dimensions

Dimensions

7 x 10 x 2.5 cm, excluding extension

Length of extension

3.8 cm

Weight

180 g

General

Operating temperature

From -20 %C to +50 %C

Guarantee

1 year

Average service time

5 - 10 years, depending on use

Storage and transportation

Long shelf life: 10+ years in dry environment

Typical Storage and transport: -20°C to +50°C, 10 to 90% humidity non-condensing

Correspondence

RoHS compliant

TUV Certification

Certificate No.:CU 72101153 01

Tested to: UL 61010-1: 2009 R10.08

CAN/CSA-C22.2 61010-1-04 + Gi1

Connectors

USB

Standard USB Mini connector. (The X-123SDD is not USB powered.)

RS232

Standard 2.5mm headphone jack.

TipTransmitFor PC Receive DB9 pin 2 (to DB25 pin 3)RingReceiveFor PC Transmit DB9 pin 3 (to DB25 pin 2)SleeveGroundFor PC Ground DB9 pin 5 (to DB25 pin 7)

Ethernet

Standard Ethernet connector (RJ-45)

Nutrition

Hirose MQ172-3PA (55), Plug Mating: MQ172-3SA-CV

Auxiliary

2x8 16-pin 2mm (Samtec part number ASP-135096-01). Mates with Samtec P/N TCMD-08-S-XX.XX-01. Top row odd contacts, bottom row even contacts. Top right contact = 1, bottom right contact = 2.

Pin #	Name	Pin #	Name
1	SCA1	2	SCA2
3	SCA3	4	SCA4
5	SCA5	6	SCA6
7	SCA7	8	SCA8
9	AUX_IN_1	10	AUX_OUT_1
11	AUX_IN_2	12	AUX_OUT_2
13	IO2	14	IO3
15	GND	16	GND

Software interface

DPPMC

The X-123SDD can be controlled by the Amptek DPPMCA display and dedicated software. This program completely controls and configures the X-123, acquires and displays the data. It supports ROI, calibration, peak search, etc. The DPPMCA software includes an interface for XRF analysis and a software package. It runs under Windows XP PRO SP3 or later.

SDK

X-123SDD comes with a free software development kit (SDK). The user can use this kit to write their own code to control X-123SDD to solve their own problems.

VB demo software

The VB demo software runs on a personal computer and allows the user to configure the X-123SDD, start and stop data collection, and save data files. It comes with source code and can be modified by the user. This software is intended to demonstrate how to control the X-123SDD manually or via the USB or RS-232 interface using basic commands without an SDK. This is primarily needed when writing software for non-Windows platforms.

Option

Other beryllium window thicknesses are available upon special order (0.3 mil - 7.5 µm).
A set of collimators for working with large flows.
Vacuum equipment
Can be used as a component of OEM systems

x123_h

Fig.4 X-123SDD in extended versions.

oem18

Fig.5 X-123 with PA-230 preamplifier in the case. This option is similar to the X-123 detector itself, except that the detector/preamplifier is removed from the electronics case and connected to it via a flexible cable.

Working in a vacuum

The X-123SDD can operate in both air and vacuum at pressures up to 10-8 Torr. There are two options for operating the X-123SDD in vacuum: 1) The entire X-123SDD detector and preamplifier can be placed inside the chamber. In order to avoid overheating and dissipating the 1 W of power required to operate the X-123SDD, good thermal conductivity to the chamber walls must be ensured using four mounting holes. 2) The X-123SDD can be located outside the vacuum chamber, a standard ConFlat port is used for X-ray detection in the chamber.

Additional information about the system

Fig.6 Plot of resolution versus peak time for a silicon drift detector (SDD).

Fig.7 Resolution dependence on Formation time/Peak time for Si-PIN and SDD detector.

Fig.8 Resolution versus count rate for different peak times.

Fig.9 Spectrum of 55Fe from 4 million measurements obtained with a silicon drift detector (SDD).

sdd_9

Fig.10 Plot of resolution versus energy for different peak times obtained with a silicon drift detector (SDD).

sdd_15

Fig.11 The figure combines the effect of beryllium glass permeability (including the protective layer) and interaction with the SDD detector. The low-energy region on the graph is determined by the thickness of the beryllium glass - 0.3 mil (8 μm) or 0.5 mil (12.5 μm), while the high-energy region is characterized by the thickness of the active zone of the SDD detector.

Additional spectra