1. Beam diagnostics in the beamlines
Sergey Sadovich
CERN BE-BI-PM on behalf of BE-BI-PM

2. Outline HIE-ISOLDE diagnostic system overview
Short and long diagnostic boxes
Instruments and devices
Faraday Cup
Scanning slit
Collimator and stripping foils
Silicon detector

3. Diagnostic boxes:

4. Possibilities: Beam current measurement
Profile and position measurement
Beam emittance
Energy of beam measurement
Stripping foils

5. Types of DB:

6. Short and Long diagnostic boxes
Due to tight space constraints in the longitudinal direction, two designs for the DBs were implemented: Linac: Short DBs (5). HEBT: Long DBs (8). The functionality and operation of the instruments is similar in the SDBs and LDBs. The only difference between them is that the SDBs have a compact Faraday cup. Depending on which devices are included on each DB, there can be up to 4 different types/configurations of DBs.
scanning slit
stripping foils FC
Si. det
collimators
vacuum port
beam
short FC
long FC

7. Instruments summary Instrument Inputs Outputs Plane * Positions
Connected to
Faraday cup
V repeller
I signal plate 2
IN – OUT
FC preamplifier + VME board
Scanning slit 1
continuous stroke 135 mm
Si detector HV
particle energy and time of arrival
and continuous adjustment
preamplifier + VME digitizer V1724
Collimators 1
4 setpoints and continuous adjustment
Collimators 2
Stripping foils
3 setpoints and continuous adjustment

8. Faraday Cup
FC working zone
Design for short FC
Ibeam
IFC
Vrep
-67 V

9. Faraday Cup
Final design
Ibeam
IFC
Vrep

10. Scanning slit A blade with a V-shaped slit is scanned upstream the FC.
Detector
Beam
A blade with a V-shaped slit is scanned upstream the FC.
Vertical and horizontal profiles are acquired, and the beam position is calculated from them.
A 1 mm collimator hole is also included in the blade and can be used for beam alignment.
The position of the blade needs to be controlled for the full stroke (135 mm). The actuator is driven by a stepper motor.

11. Transverse profile: scanning slit + FC
Horizontal and vertical profiles.
Beam size and position.

12. Transverse emittance: 2 slits + FC
can be implemented with 2 DBs at the HEBT (d = 2.6 m)
MonteCarlo simulation of particles transport
optimal slit width w = 1 mm

13. Scanning slit: position measurement

14. Collimators and stripping foils
Preset positions (1 to 4, or OUT) or arbitrary value. Actuator driven by a stepper motor.

15. Collimators: position measurement

16. charged particles spectroscopy
Silicon detector
preamplifier
energy chain
charged particles spectroscopy
Total particle energy
Mass composition
timing chain
time of flight
Particle speed
Bunch length
energy spectrum
TOF spectrum
Works at an average rate of ~100s particles per second. Beam intensity needs to be severely reduced placing collimating foils in DB2 and DB3.
Detector bias (60 or 100 V) supplied through the preamplifier.
Preamplifier power: ±24 V, ±12 V provided by shaper amplifier.
Leakage current monitoring can be used to determine detector aging and also to block the beam if dose rate is too high.
Requires the time signal for the RF master-oscillator and the EBIS pulse for triggering the TDC and gating the acquisition.
Integration time controlled by the user.

17. Implementation: Canberra PIPS detector (TM)PD50-11-300AM 50 mm2
Resolution 11(16) keV FWHM for 241Am, MeV alphas
Canberra 2003BT
The output provides a voltage in direct proportion to the collected charge at the rate of 0.45 V per pC. This translates to a gain of 20 mV per MeV for room temperature silicon detectors.
CAEN V1724 with DPP-PHA
VME module with 8 Channels 14 bit 100 MS/s Flash ADC Waveform Digitizer and featuring 10 Vpp input dynamics
0-10V /20 mV = MeV
500 MeV / 2^14 = 30.5 keV per bit

18. Summary DBs in tunnel are installed DBs for XT01 line are installed
DBs for XT02 line are ready to be installed
Stripping foils have to be installed
Silicon detectors for SDB5 and LDB6 have to be installed
Following measurements can be performed
Beam intensity: Faraday cup (+ collimators).
Setting up the accelerator and aligning and transporting the beam.
Beam transverse profiles (and position): Scanning slit + FC.
Horizontal and vertical profiles.
Beam longitudinal profile: Silicon detectors.
Energy and time spectra.
Time of flight measurements
Transverse emittance: 2 scanning slits + FC
Stripping foils.