application oriented hpge detector solutions · application oriented hpge detector solutions i....
TRANSCRIPT
-
Application Oriented HPGe Detector Solutions
I. Kojouharov, GSI Darmstadt
BgNS Conference, 10-13
September, Sv.Vlas, Bulgaria
-
Application Oriented HPGe
Detector SolutionsI. Kojouharov, GSI Darmstadt
BgNS Conference, 10-13
September, Sv.Vlas, Bulgaria
HPGe detectors vs. scintillation detectors
Advantages: Superior energy resolution
Energy range from
-
Application Oriented HPGe
Detector SolutionsI. Kojouharov, GSI Darmstadt
BgNS Conference, 10-13
September, Sv.Vlas, Bulgaria
The HPGe detector has to be considered as a very complex instrument
n-type HPGe
p+ at HV (B) n+ at HV (Li)
n+ at ~ GND (Li) p+ at ~ GND (B, Au)
p-type HPGe
Bulletization
n-type HPGe
n+ at ~ GND (Li, a-Ge)
p+ at HV (B)
p-type HPGe
n+ at ~ GND (Li, a-Ge)
p+ at HV (B)
Guard
Ring
Coaxial P- or N- Type
Planar P- or N- Type
Typically Cold FET as an input stage.Resistive or pulsed Feedback?AC or DC coupled?
Geometry?
Cooling agent?
Window?
Radiation damages?
Low Background?
-
Application Oriented HPGe
Detector SolutionsI. Kojouharov, GSI Darmstadt
BgNS Conference, 10-13
September, Sv.Vlas, Bulgaria
Criteria by choosing the detector – the
experiment/measurements specific
- Energy Range – determines the type of the crystal geometry. Low energies
(
-
Application Oriented HPGe
Detector SolutionsI. Kojouharov, GSI Darmstadt
BgNS Conference, 10-13
September, Sv.Vlas, Bulgaria
Criteria by choosing the detector – the experiment/measurements specific
The standard detectors are in many cases not optimal for the application.
- Is the experiment at beam => all attitude orientation of the detector?
- Are the measurements “in situ” – portable detector? Crystal size rate 1:1
or similar.
- Low background solution – the quality of the crystal holder and detector
End Cap has to be chosen carefully. Copper or Creal? Also Carbon
fibers EndCap?
- Cryostat geometry – vertical dipstick, side looking or any suitable
shape…? What is the optimal solution for your application.
A specific solution for full body counting
-
Application Oriented HPGe
Detector SolutionsI. Kojouharov, GSI Darmstadt
BgNS Conference, 10-13
September, Sv.Vlas, Bulgaria
- High count rate expected – has large impact on the efficiency and the type of the preamplifier. High
count rate may require pulsed feedback (transistor reset preamplifier) and/or small volume
(efficiency) detector.
- Multicrystal assembly (composite detector, used predominantly in the fundamental research
experiments. Coming soon in the medicine and other applications.) – may require AC coupling of the
preamplifier.
Criteria by choosing the detector – the experiment/measurements specific
The standard detectors are in many cases not optimal for the application.
U=Q/CF
Resistive Feedback
t = RFCF
U=Q/CF
Pulsed Feedback:
- Optical
- Transistor reset
Negative Feedback
CF
RF
CF
Courtesy of J.Kojouharova
-
Application Oriented HPGe
Detector SolutionsI. Kojouharov, GSI Darmstadt
BgNS Conference, 10-13
September, Sv.Vlas, Bulgaria
- Is LN2 broadly available or one has to go to electrical
cooling? LN2 Recycler?
- Permitted by regulations use of LN2? Autofill?
Criteria by choosing the detector – the experiment/measurements specific
The standard detectors are in many cases not optimal for the application.
48 V power
supply
Test fixture
Cooling fins
Controller
-
Application Oriented HPGe
Detector SolutionsI. Kojouharov, GSI Darmstadt
BgNS Conference, 10-13
September, Sv.Vlas, Bulgaria
- The HPGe detectors are more expensive as the scintillators.
One has to deal with ca. 600-1200 € per % efficiency for
standard geometry.
- Maintenance cost. A standard Pop Top Capsule needs vacuum
conditioning every 3-5 years, a standard VD detector every 5-7
years, GG detector as well.
- Autofill (if needed) piping – renewing every 6-12 months.
Criteria by choosing the detector – the cost factor
-
Application Oriented HPGe
Detector SolutionsI. Kojouharov, GSI Darmstadt
BgNS Conference, 10-13
September, Sv.Vlas, Bulgaria
- Application oriented geometry and structure –
preferable as an optimal solution. Elevated cost,
however may have much higher operational capability.
Criteria by choosing the detector – the cost factor
-
Application Oriented HPGe
Detector SolutionsI. Kojouharov, GSI Darmstadt
BgNS Conference, 10-13
September, Sv.Vlas, Bulgaria
The DESPEC – 0 Experiment setup – an application oriented solution
HISPEC (High-resolution
In-flight SPECtroscopy)
Runs AGATA as the basic
spectrometer
Super FRS
DESPEC (DEcay SPECtroscopy)
Runs DEGAS as the basic spectrometer –
DESPEC-0 Experiments
Collaboration of:
• Germany
• India
• Turkey
• Romania
• Spain
• Sweden
• UK
• Finland
-
Application Oriented HPGe
Detector SolutionsI. Kojouharov, GSI Darmstadt
BgNS Conference, 10-13
September, Sv.Vlas, Bulgaria
The DESPEC – 0 Experiment setup – an application oriented solution
GALILEO Solution
DEGAS Solution
-
Application Oriented HPGe
Detector SolutionsI. Kojouharov, GSI Darmstadt
BgNS Conference, 10-13
September, Sv.Vlas, Bulgaria
The DESPEC – 0 Experiment setup – an application oriented solution
-
Application Oriented HPGe
Detector SolutionsI. Kojouharov, GSI Darmstadt
BgNS Conference, 10-13
September, Sv.Vlas, Bulgaria
Thank you