Advanced European Infrastructures for Detectors at ... · connection to a 16-bit ADC. Furthermore, an Arduino Yún in the BPM system collects the data from the ADC and controls its

AIDA-2020-POSTER-2016-001

AIDA-2020Advanced European Infrastructures for Detectors at Accelerators

Poster

The Beam Profile Monitoring System forthe IRRAD Proton Facility at the CERN

PS East Area

M. Glaser (CERN)

10 November 2015

The AIDA-2020 Advanced European Infrastructures for Detectors at Accelerators projecthas received funding from the European Union’s Horizon 2020 Research and Innovation

programme under Grant Agreement no. 654168.

This work is part of AIDA-2020 Work Package 15: Upgrade of beam and irradiation testinfrastructure.

The electronic version of this AIDA-2020 Publication is available via the AIDA-2020 web site<http://aida2020.web.cern.ch> or on the CERN Document Server at the following URL:

<http://cds.cern.ch/search?p=AIDA-2020-POSTER-2016-001>

Copyright c© CERN for the benefit of the AIDA-2020 Consortium

Beam Profile Monitor (BPM) Hardware

Beam Profile Monitor (BPM) Software & Display

For small samples irradiation, a remote-controlled shuttle system is installed in the IRRAD area,together with a series of remote-controlled tables for the irradiation of large samples, detectorcomponents and prototypes. On the tables it is possible to perform irradiation experiments at lowtemperature (up to -25°C) and on powered equipment. The tables are located in three separatedshielded zones in order to minimise the particle scattering as well as to reduce the radiation dose tothe personnel accessing the area. IRRAD is also equipped with a cryostat that is fed with liquidHelium for special irradiations at cryogenic temperature down to 1.8K.

Proton IRRAD Facility

Poster presented at: 12th International Topical Meeting on Nuclear Applications of Accelerators (AccApp '15) - Washington, DC, November 10-13, 2015

ABSTRACTIn particle physics experiments, devices are frequently required to withstand a certain radiation level. As a result, detectors and electronics must be irradiated to determinetheir level of radiation tolerance. To perform these irradiations, CERN built a new Irradiation Facility in the East experimental area at the Proton Synchrotron (PS) accelerator. Atthis facility, named IRRAD, a high-intensity 24 GeV/c proton beam is used to irradiate samples. During the irradiation it is necessary to monitor the intensity and the transverseprofile of the beam as it irradiates devices. The PS East Area Irradiation Facility beam profile monitor (BPM) uses 39-channel pixel detectors to monitor the beam position.These pixel detectors, that must withstand high cumulated radiation levels, are constructed using thin foil copper pads positioned on a flex circuit. When protons passthrough the copper pads, they induce a measurable current. To measure this current and determine the total flux of protons passing through the thin foil copper detectors,a new data acquisition system was designed as well as a new database and on-line display system. In its final configuration, the IRRAD facility exploits 4 BPM deviceslocated along the path of the irradiation beam.The new BPM data acquisition system uses low noise integrators attached to each channel for measuring the total particle flux through each pixel during spills from the PS. Thedetector pixels are connected to the integrators by a shielded, 25 meter long, 40-channel, micro-coaxial cable. The voltages from each integrator are scaled and limited beforeconnection to a 16-bit ADC. Furthermore, an Arduino Yún in the BPM system collects the data from the ADC and controls its transmission over the Ethernet port to a IRRADserver for further processing and storage. Finally, the live beam position and intensity data are available to the IRRAD users, as well as to the operators at the CERN ControlCentre, via a dedicated web-based display.Two BPM data acquisition systems were assembled in 2014 and were used to read out two pixel detectors during the commissioning of the new IRRAD Proton IrradiationFacility. Additional BPM data acquisition systems were assembled and installed at the beginning of the irradiation run 2015. The BPM systems are now fully operational andhave been used for sample alignment during proton irradiations in 2014 and 2015. In this work, we present the design and the architecture of the BPM system and results onits performance during the commissioning and beam development of the IRRAD proton beam.

East Area Irradiation Facilities Project (EA-IRRAD)

The East Area has been operating for many years with aging equipment, increasedfailure rates and high dose levels. A consolidation program for the whole of the EastArea has been proposed in two phases. The first phase took place in 2013-2014during CERN LS1. During this period, the DIRAC experiment was dismantled and anew irradiation facility, combining a proton irradiation facility (IRRAD) and a mixedfield facility (CHARM), is being installed in the old DIRAC location. Such an irradiationfacility at CERN is necessary to test and validate detectors for HEP experiments (inIRRAD) and complete electronics systems for accelerators (in CHARM). Theadvantages of such a new facility are numerous:

1. as the facility has no more competition for protons from the DIRAC experiment,more protons will be available for irradiations;

2. in many cases the same protons can serve irradiations in IRRAD and CHARM;3. much more space and shielding will be available and the irradiation areas will

be equipped with a state-of-the-art ventilation system;4. the layout is optimised to reduce doses to the personnel during intervention;5. the increased space allows irradiating larger objects, even in operation with

services;6. the access will only stop the facility itself, not the beam to the other East Area

users.

Proton Beam Characteristics

THE BEAM PROFILE MONITORING SYSTEM FOR THE IRRAD PROTON FACILITY AT THE CERN PS EAST AREAMaurice Glaser, Blerina Gkotse, Emanuele Matli and Federico RavottiPH and BE Department, CERN, CH-1211, Geneva 23, Switzerland

Kock Kiam Gan, Harris Kagan, Shane Smith and Joseph WarnerThe Ohio State University, Columbus, OH, USA WEB: www.cern.ch/irradiation, E-MAIL: [email protected]

T11

p+

24 GeV/c

PSring

The East Area contains 4 beam lines:T8, T9, T10 and T11. The beam linesare derived from the 24GeV/cprimary beam of the PS, whichprovides 2.4s cycles with a flat top ofabout 400ms. Some cycles serve theNorth target (for T9, T10 and T11),some the South branch (for T8)

Mixed-field Facility(CHARM)

Vmax=5×5×15cm3

Irradiation Tables

Access Chicane

Zone 3

Zone 2Zone 1

Cryogenic System

Cryostat

Temp.: -25 ºC

Temp.:-20 ºC

Proton Facility(IRRAD)

Beam Dimensions• Several optic variants possible on T8

• Standard size: 15x15 mm2 (FWHM)

• Spot size from 5x5 to 20x20 mm2

Secondary Electron Emission (SEE) from Thin Metal Foils: Choice of the Detector Material

ControlRoom

www.cern.ch/irradiation

Shuttle System

T8

Vmax=20×20×50cm3

Beam Intensity• p+ are delivered in “spills” of ~3.5×1011 p

• No. of spills/frequency depends on CPS

• Typical CPS from 2014: 30s

• Typical figures (high intensity): 3 spills/CPS• ~1 × 1016 p cm-2 5days-1

(15x15 mm2 FWHM)• about 4x more than the old facilities!

• Design figures (maximum): 6 spills per CPS• ~1 × 1017 p cm-2 4days-1

(5x5 mm2 FWHM)

39 separate 4x4mm2 pads (beam profile) 0.5mm spacing between pads covers a 36mm x 27mm (x,y) area 6 layer Kapton/Cu flex circuit

‒ top and bottom layer shields‒ pads on internal layers connected through vias

pad thickness (Cu) 1.75μm / layer Kapton thickness 120μm / layer overall thickness ~700μm

1 single 5x5mm2 pad (irradiation systems alignment)

The need for an on-line method to determine the position and the profile of the IRRAD proton beammotivated a feasibility study of an instrument based on the proton-induced Secondary Electron Emission(SEE) from thin metal foils. The foils are required to be made of a low cost and relatively short radio-activity lifetime material. Moreover they have to be on the one hand thin to avoid scattering of beambut on the other hand thick enough to allow easy handling. Finally, the material has to show an SEEyield strong enough to avoid the usage of a external bias in the IRRAD beam and thus maintain thesimplest operation principle as possible.

Al and Cu foils were chosen as a good compromise to Satisfy these requirements

15 meters

time ~ 450 ms (PS proton extraction)Signal (V) ~ 250 mV at center of

beam spot. S/N = 5

Amplifier45 pA/V

V (5

0 m

V/di

v)

t (50 ms/div)

The BPM test setup consisted of a 3x3 cm2, 100µm thickAl foil mounted transversally on the IRRAD proton beam.At a fixed vertical position the foil was displaced todifferent horizontal positions ranging from 0mm to90mm and the charge integrated over one particle spillwas measured in order to get a horizontal profile.

BPM Test Setup

Comparison with other beam profiling techniques

BPM 4

Digitizes BPM detector signals in the 10pA to 500pA range

‒ dynamic range adjustable Uses commercial off the shelf, low-noise

switched integrators to amplify the BPM signals

‒ Texas Instruments ACF2101‒ TI ADS1115 (16 bit, 2-3 bits noise)

50 Channels‒ 40 channels via a 20 meter

micro-coaxial cable to the BPM detector (up to 35m)

‒ 10 channels (auxiliary LEMOs on the front panel) to readout the single pad detectors

System installed next to the PS timing distribution Local Server collect and send data to ORACLE Database

‒ Beam positions are recorded for later analysis Real time information displayed on a web-page and

used by:‒ IRRAD OP team and users to check beam quality and

alignment of irradiation systems‒ PS operation team at CERN Control Center (CCC) to tune

the T8 beam Total proton flux through irradiated samples can be

estimated using only the BPM data‒ linear behaviour BPM signal vs. beam intensity

Detectors

Data Acquisition System

BPM 3

BPM 2BPM 1

single pad

Location of multi-pads BPM detectors in IRRAD

Multi & single BPM detectors

System Architecture

BPM rack IRRAD and PS timing distribution

DAQ Controlled by Arduino Yún Communication over Ethernet Time handling for DAQ

BPM Display

DAQ System Timing

Future Upgrade

Secondary Emission Chamber(PS Beam Instrumentation)

Integral of BPM Pads SignalBPM Voltage vs. SEC cts.

www.cern.ch/opwt

Beam Integral

BPM Display Page

BPM PADs

Horizontal and Vertical Beam

Profiles

Summary Page containing all

BPM detectors

“reply” function to display the archived beam profile data

Beam Intensities from both multi-

pads and single pad BPM detectors

The single pad BPM detectors are used

during IRRAD operation to monitor on-line the

position of the irradiation equipment

The summary page allows the

simultaneous monitoring of the

beam position along the IRRAD facility (beam steering)

BPM “all” PageBeam Intensity Page

Mini-BPM device for precise alignment of

irradiation equipment and or “big” samples

Increased space resolution w.r.t. single BPM

devices

Mini-BPM profiles for alignment

INTEGRATORS 50 CHANNELS

ARDUINO YUN

BPM3

INTEGRATORS 50 CHANNELS

BPM4

INTEGRATORS 50 CHANNELS

ARDUINO YUN

BPM1

ARDUINO YUN

BPM2

SERVER

COLLECTION

CONVERSION

INTEGRATORS 50 CHANNELS

ARDUINO YUN ORACLE DATABASE

WEBSITE

BEAM TRIGGER

Up to 4 mini-BPM and 4 pad readout with one system